Improvements in time-of-flight mass analyzers

Abstract

Arrangement (10) comprising a vacuum chamber (20) and a time-of-flight mass spectrometer (30), wherein the time-of-flight mass spectrometer (30) is contained in the vacuum chamber (20), wherein the time-of-flight mass spectrometer (30) comprises a first electrode (51a) and a second electrode (61a), the second electrode (61a) being spaced from the first electrode (51a) by a distance defining a portion of an ion flight path therebetween; wherein the assembly (10) further comprises a first support (120) for supporting the first electrode (51a), the first support (120) being arranged between an inner side (21) of the vacuum chamber (20) and the first electrode (51a); wherein the first carrier (120) is configured to allow relative movement between at least a portion of the inside (21) of the vacuum chamber (20) and the first electrode (51a); wherein the vacuum chamber (20) is thermally coupled to the first and / or second electrode(s) by one or more flexible heat conductors (150), and wherein the inside (21) of the vacuum chamber (20) and the first electrode (51a) are thermally coupled.

Description

Field of the invention

[0001] This invention relates to improving bakeout efficiency, improving thermal compensation, and reducing stress and friction on the components of a time-of-flight mass analyzer. Background of the invention

[0002] In time-of-flight (TOF) mass spectrometry, the flight times of ions are measured to determine mass-to-charge ratios (m / z). The time of flight of an ion is known to be proportional to the square root of its mass-to-charge ratio. The recorded detection time is related to the m / z ratio by a calibration function. The ambient temperature of a mass spectrometer can vary by more than 10 degrees Celsius during use, leading to thermal expansion of the mechanical parts and induced drift of the electronic components (power supplies). Temperature fluctuations of the TOF-MS lead to changes in the measured time of flight of ions of a given species and therefore to drifts in the measured m / z of the ions.

[0003] Several approaches have been taken in the past to minimize these effects. For example, the mass calibration can be updated frequently to adequately account for drift, either using a known analyte or compared to a second, much more stable analyzer, as discussed in US 10,593,525 B2. Alternatively, the system can be temperature-controlled to reduce drift. However, this increases cost and technical complexity. As another example, in US 6,700,118 B2, multiple sensors are used to obtain temperature and strain measurements from the instrument. The measured parameters are then used in conjunction with a mathematical model to provide fitted mass spectra.

[0004] US 6,998,607 B1 relates to a thermal compensation scheme in a time-of-flight mass analyzer, where the analyzer is designed such that, although material may expand / contract with temperature, their actual ion flight path length remains approximately the same. This is achieved by using a spacer attached to the detector, which, upon thermal expansion, reduces the distance between the ion source and detector to reduce the flight path length between the ion source and detector. This reduction in flight path compensates for the increase in flight path caused by the other components of the analyzer. As a result of this arrangement, however, friction between the spacer and the detector can hinder smooth expansion / contraction.

[0005] DE 198 82 719 T5 relates to a portable time-of-flight mass spectrometer in which, for the adjustment of the reflectron, a canister containing the ring electrodes is held by a ball joint and a movable mounting rod to enable angular positioning. WO 2003 / 058 673 A2 relates to an adaptive mount for elements of a mass spectrometer, such as an ion detector or electrodes, in which remotely controllable, shape-variable mounting elements such as piezoelectric actuators are used to adjust the position of an element to improve resolution. WO 2009 / 081 444 A1 relates to a mass spectrometer with a mechanism for compensating for temperature fluctuations in which electrodes made of a material with general thermal expansion are mounted on a support element, which in turn is attached to a base made of a material with low thermal expansion to minimize temperature-induced changes in time-of-flight.

[0006] It should also be noted that due to their much longer flight path length, it is difficult to apply known thermal compensation techniques to multiple reflection time-of-flight mass analyzers. Their much longer flight path length requires excellent vacuum conditions, typically at least an order of magnitude lower than conventional analyzers. Therefore, the vacuum chamber housing the analyzer must be baked to perform outgassing. During bakeout, the vacuum chamber is heated to 80–120 °C for approximately 4–24 hours. Outgassing is the consequent removal of contaminants from the interior of the vacuum chamber during bakeout. To be usable after bakeout, the analyzer must be cooled. However, efficient heating / cooling requires good thermal coupling between the analyzer and the vacuum chamber.In known arrangements, good thermal coupling requires that the inside of the vacuum chamber and the analyzer be tightly secured. Consequently, a force is transferred from the thermal expansion / contraction of the vacuum chamber to the analyzer, exerting stress on the analyzer components and negating the effectiveness of the applied thermal compensation techniques.

[0007] The present invention attempts to solve some of these problems of prior art devices. Brief description of the invention

[0008] The invention provides an arrangement comprising a vacuum chamber and a time-of-flight mass spectrometer, wherein the time-of-flight mass spectrometer is contained in the vacuum chamber, wherein the time-of-flight mass spectrometer comprises a first electrode and a second electrode, the second electrode being spaced from the first electrode by a distance defining a portion of an ion flight path therebetween; wherein the assembly further comprises a first support for supporting the first electrode, the first support being disposed between an inner side of the vacuum chamber and the first electrode; wherein the first support allows relative movement between at least a portion of the interior of the vacuum chamber and the first electrode; wherein the inside of the vacuum chamber and the first electrode are thermally coupled.

[0009] The arrangement allows the first carrier to be thermally coupled to the vacuum chamber while also allowing the first carrier to move relative to the vacuum chamber.

[0010] During bakeout, the vacuum chamber is heated to remove contaminants from the inside of the vacuum chamber. In order for the analyzer to be used after bakeout, the analyzer must be cooled. The first aspect of the present invention thermally couples the vacuum chamber and the first electrode of the analyzer to enable efficient heating / cooling during bakeout. However, this also reduces stress and friction on components of the analyzer, particularly the electrodes, as the vacuum chamber can expand / contract without exerting force on the electrodes, as the first support allows the inside of the vacuum chamber to move relative to the first electrode. This also prevents thermal expansion / contraction of the vacuum chamber from significantly affecting the thermal compensation scheme used for the analyzer.

[0011] The vacuum chamber includes or defines a cavity in which the time-of-flight mass spectrometer is housed.

[0012] The inside of the vacuum chamber can be any inside formed by walls of the vacuum chamber.

[0013] The analyzer may comprise an ion source and an ion detector. The entire ion flight path runs from the ion source to the ion detector (via the first and second ion optical mirrors).

[0014] The first carrier can be connected to the inside of the vacuum chamber. The first carrier can be connected directly to the inside of the vacuum chamber and / or directly to the first electrode.

[0015] Preferably, the assembly may comprise a second support for holding a second electrode. The second support may have a similar configuration to the first support. The second support is arranged between the interior of the vacuum chamber and the second electrode, wherein the second support allows relative movement between at least a portion of the interior of the vacuum chamber and the second electrode.

[0016] The second carrier can be connected to the inside of the vacuum chamber. The second carrier can be connected directly to the inside of the vacuum chamber and / or directly to the second electrode.

[0017] Preferably, the first and / or second carrier comprises a surface configured to support the respective electrode thereon, wherein the surface is electrically insulating. The respective electrode may be supported directly on the surface of the carrier. The first and / or second carrier may be coated with an electrically insulating material or may be formed entirely from an electrically insulating material to provide the electrically insulating surface.

[0018] The first and / or second support allows relative translation of the respective electrode relative to at least a portion of the interior of the vacuum chamber. (That is, the aforementioned relative movement may be a relative translation.) The relative translation may occur in any direction.

[0019] In one embodiment, the first and / or second support comprises one or more rotatable elements, each rotatable element having a curved surface configured to support the respective electrode thereon. The curved surface may be electrically insulating. Rotation of the one or more rotatable elements may enable relative translation between the electrode(s) and the interior of the vacuum chamber. The curved surface may be in direct contact with the respective electrode, but not the interior of the vacuum chamber. Alternatively, the curved surface may be in direct contact with the respective electrode and the interior of the vacuum chamber. For example, each support may comprise a plurality of rotatable elements spaced along a longitudinal direction of the respective electrode.

[0020] Each rotatable element may be a ball, wherein the ball is received by a holder such that the ball is rotatable relative to the holder, and wherein the holder is coupled to the inside of the vacuum chamber. The holder may be formed from a flexible material or shaped to provide flexibility. The holder may be mounted directly to the inside of the vacuum chamber. The holder may flexibly maintain the position of the respective ball. The holder may limit the translation of the respective ball.

[0021] Preferably, the interior of the vacuum chamber has a complementary recess for receiving each rotatable element. The complementary recess can accommodate the ball and / or the holder of the rotatable element.

[0022] In an alternative arrangement, each rotatable element can be a cylinder.

[0023] In one embodiment, the first carrier and the second carrier are integrally formed. In other words, the first carrier and the second carrier may form a single, unified structure.

[0024] The first and / or second carrier may comprise a lubricated layer that is electrically insulating. The lubricated layer may also be thermally conductive, thereby providing thermal coupling between the electrode(s) and the inside of the vacuum chamber. The lubricated layer may extend between the inside of the vacuum chamber and the respective electrode. The first carrier may be a first portion of the lubricated layer, and the second carrier may be a second portion of the lubricated layer. The first and second portions of the lubricated layer may be separate from each other. Alternatively, the first and second portions may form a unitary lubricated layer such that the first and second carriers are integrally formed. The lubricated layer may comprise vacuum grease and / or soft metal, such as indium foil.

[0025] The first and / or second carrier may comprise a layer having a low coefficient of friction and formed from an electrically insulating material, such as low-friction plastic / Teflon. The layer may also be thermally conductive. The first carrier may be a first portion of the layer, and the second carrier may be a second portion of the layer. The first and second portions of the layer may be separate from each other. Alternatively, the first and second portions may form a unitary, lubricated layer such that the first and second carriers are integrally formed.

[0026] In one embodiment, the first and / or second support comprises one or more wires configured to suspend the respective electrode from the inside of the vacuum chamber. Preferably, in this arrangement, the inside of the vacuum chamber is a top side of the vacuum chamber. The one or more wires may be formed from a thermally conductive material. The one or more wires may be at least partially covered by an electrically insulating material. The one or more wires may be compressed and / or combined at their ends.

[0027] In one embodiment, the first and / or second support comprises one or more springs extending between the interior of the vacuum chamber and the electrode(s). The one or more springs may be formed from a thermally conductive material. Each spring may extend between a support connected to the interior of the vacuum chamber and a support connected to the surface of the respective electrode. Alternatively, each spring may extend directly between the interior of the vacuum chamber and a surface of the respective electrode.

[0028] Preferably, the interior of the vacuum chamber and the second electrode are thermally coupled. The thermal coupling between the interior of the vacuum chamber and the second electrode may be achieved by the same or a different feature used to provide thermal coupling between the interior of the vacuum chamber and the first electrode.

[0029] The invention further provides that the thermal coupling between the vacuum chamber and one or both of the first and / or second electrodes is achieved by one or more flexible heat conductors. Preferably, the thermal coupling is achieved on the inside of the vacuum chamber. The flexible heat conductor(s) enable relative movement between the inside of the vacuum chamber and the respective electrode. Preferably, each flexible heat conductor is connected between the inside of the vacuum chamber and the respective electrode.

[0030] Preferably, each flexible thermal conductor comprises one or more thermally conductive wires. The plurality of thermally conductive wires can be joined together, for example, braided, to form a flexible ribbon. At least a portion of the one or more thermally conductive wires can be covered with an electrically insulating material.

[0031] Preferably, each flexible heat conductor comprises a first holder configured to connect the flexible heat conductor to the respective electrode and a second holder configured to connect the flexible heat conductor to the inside of the vacuum chamber.

[0032] The first and second supports can be directly connected to the inside of the vacuum chamber and the respective electrodes. Alternatively, a spacer can be provided between the first support and the respective electrode and / or between the second support and the inside of the vacuum chamber.

[0033] The first holder may be electrically insulated from the respective electrode. For example, at least the surface of the first holder in contact with the respective electrode may be formed from an electrically insulating material. Alternatively, a spacer may be positioned between the first holder and the respective electrode, which spacer is configured to space the first holder and the respective electrode, wherein the spacer is formed from an electrically insulating material or has a surface coating formed from an electrically insulating material. The first holder may be connected to the respective electrode via a bolt. The bolt may be surrounded by an electrically insulating material.

[0034] Preferably, the first and / or second support is thermally conductive, thereby thermally coupling the interior of the vacuum chamber with the respective electrode. The first and / or second support may be formed from a thermally conductive material, such as a ceramic. Flexible heat conductors may not be required in this arrangement.

[0035] Liquid cooling, which may be directly temperature-controlled, can be used to thermally couple the inside of the vacuum chamber with the electrode(s). For liquid cooling, conduits, such as flexible, sealed hoses, can be provided with a coolant flowing through them to thermally couple the electrode(s) and the inside of the vacuum chamber. The conduits can be connected between the inside of the vacuum chamber and the electrode(s). A pump can be provided to circulate the coolant, such as a cooling liquid, through the internal volume of the conduits, so that the coolant flows between the inside of the vacuum chamber and the electrode(s) via the conduit, efficiently transferring heat between them.

[0036] Flexible bellows, which can be directly temperature-controlled, can be used to thermally couple the inside of the vacuum chamber with the electrode(s). For example, the electrode(s) can be mounted on flexible bellows connected to the vacuum chamber's ports, rather than to the inside of the vacuum chamber. The flexible bellows can be directly air-cooled for temperature control.

[0037] The first electrode may be one of a first plurality of electrodes, and the second electrode may be one of a second plurality of electrodes, wherein the first plurality of electrodes are spaced from the second plurality of electrodes, thereby defining the portion of the ion flight path therebetween.

[0038] One or more of the electrodes of the first plurality of electrodes may be supported by a carrier configured similarly to the first carrier. In other words, one or more of the electrodes of the first plurality of electrodes may be supported by a respective carrier that allows relative movement between at least a portion of the interior of the vacuum chamber and the respective electrode.

[0039] One or more of the electrodes of the second plurality of electrodes may be supported by a support configured similarly to the second support. In other words, one or more of the electrodes of the second plurality of electrodes may be supported by a respective support that allows relative movement between at least a portion of the interior of the vacuum chamber and the respective electrode.

[0040] Preferably, the time-of-flight mass spectrometer is a multi-reflection time-of-flight mass spectrometer, wherein the multi-reflection time-of-flight mass analyzer comprises a first ion optical mirror comprising at least the first electrode and a second ion optical mirror comprising at least the second electrode, wherein the second ion optical mirror is spaced from the first ion optical mirror by a distance defining at least the portion of the ion flight path therebetween.

[0041] The first ion-optical mirror may comprise a first plurality of electrodes spaced apart from one another, and / or the second ion-optical mirror may comprise a second plurality of electrodes spaced apart from one another. In this arrangement, the first electrode is the electrode of the first plurality of electrodes farthest from the second plurality of electrodes, and the second electrode is the electrode of the second plurality of electrodes farthest from the first plurality of electrodes.

[0042] Supports for one or more of the electrode(s) of the first and second plurality of electrodes may be used similarly to the first and second supports.

[0043] Alternatively, the time-of-flight mass spectrometer may be a multiturn time-of-flight mass spectrometer, wherein the multiturn time-of-flight mass analyzer comprises a first electrostatic sector comprising at least the first electrode and a second electrostatic sector comprising at least the second electrode, the second electrostatic sector being spaced from the first electrostatic sector by a distance that defines at least the portion of the ion flight path therebetween. The multiturn time-of-flight mass spectrometer may also comprise further pairs of electrostatic sectors configured similarly to the first and second electrostatic sectors.For example, the multiturn time-of-flight mass spectrometer may include a third and a fourth electrostatic sector configured similarly to the first and second electrostatic sectors, wherein the fourth electrostatic sector is spaced from the third electrostatic sector by a distance defining a portion of the ion flight path therebetween. Ions may oscillate along a flight path between the first, second, third, and fourth electrostatic sectors.

[0044] The first electrostatic sector may comprise a first plurality of electrodes spaced apart from one another, and / or the second electrostatic sector may comprise a second plurality of electrodes spaced apart from one another.

[0045] A carrier for one or more of the electrodes of the first and second plurality of electrodes may be used similarly to the first and second carriers.

[0046] The ion source and detector are preferably mounted inside the vacuum chamber. In a less preferred arrangement, the detector can optionally be mounted on the ion optical mirror or the electrostatic sector near the detector, but this arrangement would require flexible electrical connections between them.

[0047] In a preferred embodiment, a thermal compensation scheme is used. The first electrode has a shift in the m / z ratio per Kelvin, and the second electrode has a shift in the m / z ratio per Kelvin; the assembly further comprises a connector connected to the first electrode at a first connection point and connected to the second electrode at a second connection point, the connector having a shift in the m / z ratio per Kelvin, the connector defining a first length between the first and second connection points at a reference temperature, the first length, the positions of the first and second connection points, and the material of the connector being selected to compensate for the sum of the shift in the m / z ratio per Kelvin in the first and second electrodes.

[0048] Thermally coupling the electrode(s) to the vacuum chamber, but supporting the electrode(s) in such a way that the electrode(s) can move relative to the vacuum chamber, while also utilizing this thermal compensation scheme, enables efficient warm-up / cooling during bakeout without compromising the accuracy of the analysis or imposing stress or friction on the analyzer components.

[0049] The thermal compensation scheme is particularly advantageous for a multiple reflection time-of-flight mass analyzer.

[0050] As discussed in the Background section, it is important to note that due to their much longer flight path length, it is difficult to apply known thermal compensation techniques to multi-reflection time-of-flight mass analyzers. In a multi-reflection time-of-flight mass analyzer, most of the variation in ion flight path with temperature occurs due to thermal expansion / contraction of the spaced electrodes.

[0051] The described thermal compensation scheme achieves efficient thermal compensation in a multiple reflection time-of-flight mass analyzer without causing significant friction between the components.

[0052] A multiple reflection time-of-flight mass analyzer may include the thermal compensation scheme described above. In particular, a multiple reflection time-of-flight mass analyzer may include: a first ion optical mirror comprising a first electrode, the first electrode having a shift of the m / z ratio per Kelvin, a second ion optical mirror comprising a second electrode, the second electrode having a shift in m / z ratio per Kelvin, the second ion optical mirror being spaced from the first ion optical mirror by a distance defining a portion of the ion flight path therebetween; a connector connected to the first electrode at a first connection point and connected to the second electrode at a second connection point, the connector having a shift in the m / z ratio per Kelvin, the connector defining a first length between the first and second connection points at a reference temperature; wherein the first length, the positions of the first and second connection points, and the material of the connector are selected to compensate for the sum of the shift of the m / z ratio per Kelvin in the electrodes of the first and second ion optical mirrors.

[0053] Preferably, the first ion optical mirror comprises a first plurality of electrodes and / or the second ion optical mirror comprises a second plurality of electrodes.

[0054] Preferably, the first electrode is the electrode of the first plurality of electrodes that is furthest away from the second ion optical mirror and / or the second electrode is the electrode of the second plurality of electrodes that is furthest away from the first ion optical mirror.

[0055] The following paragraphs apply to the thermal compensation scheme when used in the first aspect of the invention.

[0056] A change in temperature causes the mass analyzer's electrodes to expand / contract. This, in turn, causes a change in the flight path length both within and between the spaced electrodes of the mass analyzer. For example, without the connector in place, the length of the flight path section between the spaced electrodes would increase due to thermal expansion of the electrodes.

[0057] As the electrodes expand, the flight path length within the electrodes would also increase due to the increased width of the electrodes. These changes in flight path length, in turn, result in a change in the total flight time and therefore a change in the measured m / z of an ion detected by the mass analyzer. This is referred to as the m / z ratio shift per Kelvin (i.e., delta m / z). The change in flight path length due to the expansion of each electrode can be determined based on the thermal expansion coefficient of the material, its dimensions, and geometry. The flight path length affected by each electrode can also extend beyond its geometric length due to a potential drop between electrodes and into otherwise field-free regions. From the determined change in flight path length, the measured change in m / z ratio for an ion can be determined.It is understood that depending on the geometry of the mass analyzer and the electrodes, the relationship between the m / z ratio shift and the temperature perturbation (i.e., the m / z ratio shift per Kelvin) can be positive or negative.

[0058] In other words, the first electrode is associated with a shift in the m / z ratio per Kelvin (i.e., the amount of m / z shift caused by a temperature change of 1 K). For example, the first electrode may have a shift in the m / z ratio per Kelvin of -0.1 ppm / K. In such a case, a temperature change of +10 K would cause a shift in the measured mass of an ion by -1 ppm (parts per million, i.e., 0.0001%). Similarly, a temperature change of -10 K would cause a shift in the measured m / z ratio of an ion by +1 ppm.

[0059] The connector is connected to the first electrode at the first connection point and to the second electrode at the second connection point. The connector cannot move relative to the electrodes. The first connection point and the second connection point may be points on the electrodes where the electrodes are coupled (directly or indirectly) to the connectors. The connector may be directly connected to the electrodes, for example, by bolts or pins or screws or adhesive. Alternatively, the connector may be indirectly connected to the electrodes. Indirect connection of the connector to the electrode refers to an arrangement in which the connector and the electrode are connected via an intervening or intermediate member. The connector may be connected to the electrodes, for example, via one or more clamps and / or brackets.The connector may be configured to maintain the separation between the first and second electrodes, which in turn maintains the separation between the electrodes of the first ion-optical mirror and the electrodes of the second ion-optical mirror, wherein the mass analyzer is a multi-reflection mass analyzer. The first connection point is typically attached to the first electrode, and the second connection point is typically attached to the second electrode. The first connection point is typically a point on the first electrode, and the second connection point is typically a point on the second electrode. As discussed above, without the connector in place, thermal expansion of the electrodes would increase the distance between the first and second electrodes.Once the connector is in place, an increase in the width of the electrodes due to their thermal expansion would cause the proximal edges of the electrodes to approach each other, thereby reducing the distance between the first and second electrodes. However, the thermal expansion of the connector increases the distance between the first and second connection points, compensating for the increased width of the electrodes, which would otherwise reduce the distance between the first and second electrodes. Accordingly, the connector essentially maintains the distance between the first and second electrodes.

[0060] The connector may extend above or below the first and / or second electrode. In other words, the first connection point may be located on a top surface of the first electrode, and the second connection point may be located on a top surface of the second electrode. Alternatively, the first connection point may be located on a bottom surface of the first electrode, and the second connection point may be located on a bottom surface of the second electrode. The connector may optionally extend beyond the outer edge of the first electrode and beyond the outer edge of the second electrode.

[0061] With the connector in place, the m / z ratio shift of the first electrode per Kelvin depends on the thermal expansion coefficient of the material from which the first electrode is formed, its dimensions (e.g., length, width, and thickness), and the position of the first connection point. As discussed above, it is understood that depending on the geometry of the mass analyzer and the first electrode, the relationship between the m / z ratio shift and the temperature perturbation (i.e., the m / z ratio shift per Kelvin) can be positive or negative.

[0062] With the connector in place, the m / z ratio shift per Kelvin of the second electrode depends on the thermal expansion coefficient of the material from which the second electrode is formed, its dimensions (e.g., length, width, and thickness), and the position of the second connection point. As discussed above, it is understood that depending on the geometry of the mass analyzer and the second electrode, the relationship between the m / z ratio shift and the temperature perturbation (i.e., the m / z ratio shift per Kelvin) can be positive or negative.

[0063] The shift in the m / z ratio per Kelvin of the connector depends on the thermal expansion coefficient of the material from which it is formed, its length between the first and second connection points, and the positions of the first and second connection points. The length of the connector between the first and second connection points at a reference temperature is referred to as the first length. The reference temperature can be room temperature or any specified temperature. The material of the connector, the length of the connector between the first and second connection points at a reference temperature (the first length), and the positions of the first and second connection points are selected such that the shift in the m / z ratio per Kelvin of the connector can compensate for the shift in the m / z ratio of the first and second electrodes per Kelvin.

[0064] Compensation means that the shift in the m / z ratio per Kelvin of the connector counteracts the total shift in the m / z ratio of the first and second electrodes per Kelvin. That is, the material of the connector, the first length (i.e., the length of the connector between the first and second connection points at a reference temperature), and the positions of the first and second connection points are selected such that the total m / z shift of the electrodes per degree Kelvin is reduced to zero.

[0065] Preferably, the compensation is such that a sum of the shift of the m / z ratio of the connector per Kelvin and the first and second electrodes is less than ±10 ppm / K, preferably less than ±5 ppm / K, more preferably less than ±3 ppm / K, even more preferably less than ±2 ppm / K, most preferably less than ±1 ppm / K.

[0066] When the first electrode is one of a first plurality of electrodes and the second electrode is one of a second plurality of electrodes, the material of the connector, the first length (i.e., the length of the connector between the first and second connection points at a reference temperature), and the positions of the first and second connection points can be selected such that the shift in the m / z ratio of the connector per Kelvin can compensate for the total shift in the m / z ratio of the first and second pluralities of electrodes per Kelvin. For example, the sum of the shift in the m / z ratio of the connector and the first and second pluralities of electrodes per Kelvin can be less than ±10 ppm / K, preferably less than ±5 ppm / K, more preferably less than ±3 ppm / K, even more preferably less than ±2 ppm / K, most preferably less than ±1 ppm / K.

[0067] When used in the multiple reflection mass analyzer, the material of the connector, the first length (i.e., the length of the connector between the first and second connection points at a reference temperature), and the positions of the first and second connection points can be selected such that the shift in the m / z ratio of the connector per Kelvin can compensate for the shift in the m / z ratio of some or all of the electrodes of the first and second ion-optical mirrors per Kelvin. Preferably, the compensation is such that a sum of the shift in the m / z ratio of the connector and some or all of the electrodes of the first and second ion-optical mirrors per Kelvin is less than ±10 ppm / K, preferably less than ±5 ppm / K, more preferably less than ±3 ppm / K, even more preferably less than ±2 ppm / K, most preferably less than ±1 ppm / K.

[0068] Preferably, the thermal expansion coefficient of the connector is smaller than the thermal expansion coefficient of the electrode(s). For example, the thermal expansion coefficient of the connector may be ≤ 1 / 2 of the thermal expansion coefficient of the electrode(s), more preferably ≤ 1 / 5 of the thermal expansion coefficient of the electrode(s), most preferably ≤ 1 / 10 of the thermal expansion coefficient of the electrode(s).

[0069] As discussed above, the connector material, the first length (i.e., the length of the connector between the first and second connection points at a reference temperature), and the positions of the first and second connection points are selected to at least compensate for the per Kelvin shift in the m / z ratio of the electrodes. While the majority of the analyzer m / z ratio shift per Kelvin can be attributed to the electrodes, it should be noted that the connector material, the first length (i.e., the length of the connector between the first and second connection points at a reference temperature), and the positions of the first and second connection points can also be selected to also compensate for the per Kelvin shift in the m / z ratio of some or all of the analyzer components, e.g., the ion source, detector, spacers, etc.

[0070] For example, the analyzer may further comprise an ion source and a detector, wherein the entire ion flight path lies between the ion source and the detector, wherein the ion source and the detector may each have a per-Kelvin m / z ratio shift. The material of the connector, the first length (i.e., the length of the connector between the first and second connection points at a reference temperature), and the positions of the first and second connection points may be selected such that the per-Kelvin m / z ratio shift of the connector can compensate for the total per-Kelvin m / z ratio shift of the electrodes, the ion source, and the detector.For example, the sum of the shift in the m / z ratio of the connector, the first and second plurality of electrodes, the ion source and the detector per Kelvin may be less than ±10 ppm / K, preferably less than ±5 ppm / K, more preferably less than ±3 ppm / K, even more preferably less than ±2 ppm / K, most preferably less than ±1 ppm / K.

[0071] The analyzer may further comprise one or more spacers positioned between the electrodes and configured to define the distance between the electrodes, wherein each spacer may have a shift in the m / z ratio per Kelvin. The material of the connector, the first length (i.e., the length of the connector between the first and second connection points at a reference temperature), and the positions of the first and second connection points may be selected such that the shift in the m / z ratio of the connector per Kelvin can compensate for the total shift in the m / z ratio of the electrodes and spacers per Kelvin.For example, the sum of the shift in the m / z ratio of the connector, the first and second plurality of electrodes and the spacers per Kelvin may be less than ±10 ppm / K, preferably less than ±5 ppm / K, more preferably less than ±3 ppm / K, even more preferably less than ±2 ppm / K, most preferably less than ±1 ppm / K.

[0072] The material of the connector, the first length (i.e., the length of the connector between the first and second connection points at a reference temperature), and the positions of the first and second connection points can be selected such that the shift in the m / z ratio of the connector per Kelvin can compensate for the total shift in the m / z ratio of the electrodes, the ion source, the detector, and the spacers per Kelvin. For example, the sum of the shift in the m / z ratio of the connector, the first and second plurality of electrodes, the ion source, the detector, and the spacers per Kelvin can be less than ±10 ppm / K, preferably less than ±5 ppm / K, more preferably less than ±3 ppm / K, even more preferably less than ±2 ppm / K, most preferably less than ±1 ppm / K.

[0073] The compensation can be such that the total flight time (i.e., the time required for the ion to travel along the entire ion flight path from the ion source to the detector) remains essentially constant.

[0074] Preferably, the connector extends at least transversely to a longitudinal direction of the first electrode. More preferably, the connector extends substantially perpendicular to the longitudinal direction of the first electrode. Alternatively, the connector may extend substantially perpendicular to the axis intersecting the angle between the first ion-optical mirror and the second ion-optical mirror. The length of the connector may therefore extend approximately parallel to the direction along which the first and second electrodes are spaced from each other (i.e., approximately parallel to the flight path between the first electrode and the second electrode).

[0075] Preferably, the connector is in the form of a rod, which may have any cross-sectional shape, such as square, circular, etc. Alternatively, the connector may be shaped as a planar strip / rod.

[0076] Preferably, the connector is a first connector, the analyzer further comprising a second connector connected to the first electrode at a third connection point and connected to the second electrode at a fourth connection point, the second connector defining a second length between the third and fourth connection points at the reference temperature, the second connector being spaced from the first connector, preferably the second connector being parallel to the first connector.

[0077] The second connector may be configured similarly to the first connector, and the above description of the first connector applies equally to the second connector.

[0078] As discussed in more detail below, in multi-reflection time-of-flight mass analyzers, the electrodes of the first ion-optical mirror may be tilted relative to the electrodes of the second ion-optical mirror. The tilt angle (i.e., the angle between the longitudinal direction of the first electrode and the longitudinal direction of the second electrode) may preferably be 0 to 5 degrees, more preferably 0 to 2 degrees.

[0079] Preferably, the second length, the positions of the third connection point and the fourth connection point, and a material of the second connector are selected such that the angle between the first electrode and the second electrode is maintained within ±0.01°, preferably ±0.001°, after thermal expansion of the electrodes and connectors.

[0080] By using two spaced-apart connectors and appropriately selecting the material of the second connector, the positions of the connection points, and the lengths of the connectors between the connection points at a reference temperature, the tilt angle between the electrodes of the first ion-optical mirror and the electrodes of the second ion-optical mirror can be substantially maintained despite thermal expansion / contraction of the electrodes and connectors without bending the electrodes.

[0081] Preferably, the second connector is spaced from the first connector in a longitudinal direction of the first electrode.

[0082] When the electrodes expand / contract along their longitudinal direction due to their thermal expansion / contraction, the first connector can move relative to the second connector such that the distance between the first connector and the second connector is adjusted.

[0083] Preferably, the second connector is attached to the first connector only via the first and second electrodes. In other words, there may not be a direct connection between the first and second electrodes. Therefore, the connectors may not restrict the expansion / contraction of the electrodes along their longitudinal direction, and consequently, the electrodes may not bend upon thermal expansion / contraction.

[0084] To prevent the electrode assembly from drifting out of position, the second connector may preferably be mounted at a mounting position between the third and fourth connection points on an interior side of the vacuum chamber. The second connector may be connected to the vacuum chamber with a bolt / pin / adhesive at the mounting position. While drifting of the electrode assembly as a whole within the vacuum chamber is prevented, the first connector may still move relative to the second connector, such that the connectors do not restrict elongation of the electrode(s) upon thermal expansion.

[0085] The arrangement of the first aspect of the invention may further comprise one or more cooling channels, the cooling channels being arranged to cool surfaces within the vacuum chamber by transporting a cooling medium through the one or more cooling channels; a heater arranged to heat the surfaces within the vacuum chamber; and an insulating material surrounding an exterior of the vacuum chamber.

[0086] By providing an insulating material surrounding the exterior of the vacuum chamber, a heater configured to heat the surfaces within the vacuum chamber, and cooling channels arranged to cool surfaces of the vacuum chamber when supplied with cooling medium, the vacuum chamber can be heated and then efficiently cooled during bakeout. As discussed above, during bakeout, interior surfaces of the vacuum chamber are heated to remove contaminants. After heating, the vacuum chamber must be cooled before the mass analyzer can be used within it. For efficiency reasons, it is important that the mass analyzer be baked within a reasonable timeframe.The combination of insulation material, heater, and cooling channels configured as discussed above enables both efficient heating and efficient cooling of the vacuum chamber housing the mass analyzer.

[0087] This arrangement for improving thermal efficiency can be used together with the features of the first aspect of the present invention.

[0088] An outgassing device for removing contaminants from surfaces within a vacuum chamber by heating and then cooling the surfaces, comprising: the vacuum chamber for accommodating a mass analyzer; a heater arranged to heat the surfaces within the vacuum chamber; one or more cooling channels, the cooling channels being arranged to cool the surfaces within the vacuum chamber by transporting a cooling medium through the one or more channels; and an insulating material surrounding an exterior of the vacuum chamber.

[0089] The following paragraphs apply to the thermal efficiency arrangement when used in the first aspect of the invention.

[0090] Outgassing refers to the process by which contaminants are removed from the interior of the vacuum chamber. It typically occurs during the bakeout, when the vacuum chamber is heated to 80-120 °C for 4-24 hours. The vacuum chamber must then be cooled for use with the analyzer housed within.

[0091] The surfaces heated by the heater and cooled by the cooling medium within the cooling channel(s) are the insides of the vacuum chamber.

[0092] The insulating material preferably surrounds the entire exterior of the vacuum chamber. The insulating material is preferably a foam, for example, polyurethane or polypropylene foam.

[0093] The heater is preferably positioned between the insulating material and the exterior of the vacuum chamber. Alternatively, the heater may be positioned outside the insulating material, but may include one or more conduits arranged to direct hot air through openings in the walls of the vacuum chamber into the cavity formed within the vacuum chamber. Alternatively, the heater may be positioned within the vacuum chamber (i.e., within the cavity formed by the vacuum chamber).

[0094] The cooling medium received by the one or more cooling channels can be a gas or a liquid, preferably the cooling medium is air.

[0095] The mass analyzer may be a time-of-flight mass analyzer. Preferably, the mass analyzer is a multiple reflection time-of-flight mass analyzer.

[0096] The one or more cooling channels may extend around and / or through the vacuum chamber. Preferably, the one or more cooling channels may extend at least partially through the vacuum chamber and / or at least partially around the outside of the vacuum chamber. For example, the one or more cooling channels may extend around an outer perimeter of the vacuum chamber.

[0097] Preferably, the cooling channels are located within the insulating material. In other words, the cooling channels are preferably covered by the insulating material and / or at least partially housed therein.

[0098] Optionally, the one or more cooling channels extend between an inlet and an outlet. The inlet and outlet may be apertures / through holes formed in one or more walls of the vacuum chamber. Alternatively, the inlet and outlet may be formed as recesses and / or grooves formed in edges of the walls of the vacuum chamber.

[0099] The one or more cooling channels may be formed by a tube. Preferably, the tube may extend between the inlet and the outlet, which are formed as apertures in one or more walls of the vacuum chamber.

[0100] In a preferred embodiment, each cooling channel can be formed as a recess within a wall of the vacuum chamber. Preferably, each cooling channel is formed as a recess in an outer wall of the vacuum chamber. Particularly preferably, the recess formed in the outer wall of the vacuum chamber is covered by the insulating material. The recess can extend along at least a portion of the outer wall of the vacuum chamber. Alternatively, each cooling channel can be formed within an inner side of the insulating material.

[0101] Preferably, the one or more cooling channels are configured to actively cool the surfaces within the vacuum chamber during use. For example, at least one of the one or more cooling channels may comprise one or more fans configured to drive the cooling medium through the respective cooling channel. Alternatively / additionally, one of the one or more cooling channels may comprise one or more pumps configured to drive the cooling medium through the respective cooling channel. Normally, the flow of the cooling medium through the cooling channels may be restricted except when the fans and / or pumps are activated.

[0102] Preferably, the one or more cooling channels may comprise one or more heat sinks and / or heat exchangers configured to receive the cooling medium flowing through the cooling channel during use.

[0103] The assembly / device may further comprise a controller configured to control the activation and deactivation of the heater and / or the one or more fans, wherein the controller is preferably configured to activate the one or more fans after the heater has been deactivated. Therefore, in use during the bakeout, the controller activates the heater such that the heater heats the surfaces within the vacuum chamber. The efficiency of heating the surfaces within the vacuum chamber is improved due to the use of the insulating material surrounding the exterior of the vacuum chamber.After the contaminants have been removed from the surfaces within the vacuum chamber, the controller shuts down the heater operation and activates the one or more fans / pumps to drive the flow of cooling medium through the one or more cooling channels, actively cooling the surfaces within the vacuum chamber. This improves the cooling efficiency of the surfaces within the vacuum chamber, reducing the time required for annealing.

[0104] Also described herein is a method for performing outgassing to remove contaminants from surfaces within a vacuum chamber using an apparatus comprising: a vacuum chamber for housing a mass analyzer; a heater arranged to heat the surfaces within the vacuum chamber; one or more cooling channels arranged to cool the surfaces within the vacuum chamber by transporting a cooling medium through the one or more channels, wherein the one or more cooling channels comprise one or more fans and / or pumps configured to drive a cooling medium through the one or more cooling channels; and an insulating material surrounding an exterior of the vacuum chamber; the method comprising: Activating the heater to heat the surfaces inside the vacuum chamber for 4 to 24 hours at 80-120 K; Turning off the heating; Activating one or more fans and / or pumps to drive the cooling medium through the cooling channel for 4-12 hours. Brief description of the drawings

[0105] The invention may be put into practice in many different ways and some embodiments will now be described by way of example only and with reference to the accompanying drawings, in which: Fig. Figure 1 is a schematic diagram of a plan view of an arrangement according to the first aspect of the present invention when viewed from below. Fig. Figure 2 is a schematic diagram of an end view of part of the assembly according to the first aspect of the present invention, the assembly comprising first and second supports carrying first and second electrodes respectively, the assembly further comprising flexible heat conductor(s) thermally coupling the electrodes to the inside of the vacuum chamber. Fig. Figure 3 shows a schematic diagram of a carrier that can be used in the arrangement according to the first aspect of the present invention. Fig. Figure 4(a) shows a schematic diagram of an end view of part of the assembly according to the first aspect of the present invention. Fig. Figure 4(b) shows a schematic diagram of a perspective view of a flexible heat conductor that can be used in the assembly according to the first aspect of the present invention. Fig. 5 is a schematic diagram of a plan view of part of another unclaimed arrangement. Fig. 6 is a schematic diagram of an end view of part of the further unclaimed arrangement. Fig. Figure 7 is a schematic diagram of a plan view of part of the assembly according to the first aspect of the present invention, viewed from below. Fig. Figure 8 is a schematic diagram of a plan view of part of another claimed device as viewed from above, with a mass analyzer removed from the view for clarity. Fig. Figure 9 shows a graph showing the shift in m / z ratio in ppm, measured with a temperature change in Kelvin, for an arrangement according to the first aspect of the invention. Fig. 10 is a graph showing the efficiency of heating and cooling of the vacuum chamber and the mass analyzer of the arrangement of Fig. 9 during the bakeout. Fig. 11 is a schematic diagram of a perspective view of part of another unclaimed arrangement. Detailed description

[0106] Fig. Figure 1 is a schematic diagram of a top view of an assembly 10 according to the first aspect of the present invention, comprising a vacuum chamber 20 and a time-of-flight mass analyzer 30, wherein the time-of-flight mass analyzer is a multiple reflection time-of-flight (mr-TOF) mass analyzer. Although the use of a multiple reflection time-of-flight mass analyzer offers certain advantages, the inventive concept of the first aspect of the present invention as described and claimed is equally applicable to any form of time-of-flight mass analyzer, for example, multiturn mass analyzers, and the claims are to be construed accordingly. It may also be applied to other types of mass analyzers, such as Fourier transform mass analyzers and electrostatic orbital trap mass analyzers in which, for example, ions oscillate in a quadro-logarithmic potential.

[0107] The mr-TOF 30 is contained / housed within the vacuum chamber 20. The mr-TOF includes an electrode assembly 40 forming first and second opposing ion-optical mirrors 50, 60 spaced apart from each other by a distance defining a portion of the ion flight path therebetween. The first ion-optical mirror 50 includes a first plurality of electrodes 51, and the second ion-optical mirror 60 includes a second plurality of electrodes 61. The first electrode 51a is the electrode of the first plurality of electrodes 51 farthest from the second ion-optical mirror 60. The second electrode 61a is the electrode of the second plurality of electrodes 61 farthest from the first ion-optical mirror 50.

[0108] The electrodes 51, 61 are elongated in their longitudinal direction. A longitudinal direction can be defined as a direction generally aligned with the longitudinal axis of the electrodes 51, 61. The transverse direction of the electrodes 51, 61 is transverse, preferably perpendicular, to the longitudinal direction of the electrodes 51, 61. The first plurality of electrodes 51 and the second plurality of electrodes 61 are spaced apart from one another along a direction transverse to the longitudinal direction of the electrodes 51, 61.

[0109] The first plurality of electrodes 51 (i.e., the electrodes of the first ion-optical mirror 50) are tilted relative to the second plurality of electrodes 61 (i.e., the electrodes of the second ion-optical mirror 60), as described in US Pat. No. 9,136,101 B2, thereby creating a potential gradient that retards the drift velocity of the ions and causes them to be reflected back in the drift dimension (where the drift dimension is substantially aligned with the longitudinal dimension of the electrodes 51, 61) and focused onto a detector 70. Tilting the opposing mirrors would normally have the negative side effect of altering the temporal period of ion oscillations as they travel down the drift dimension, making it difficult to achieve good ion temporal focus.This is corrected with a strip electrode 80, which changes the flying potential for a portion of the mirror gap by downwardly varying the length of the electrodes of the first and second ion-optical mirrors 50, 60. Such correction or compensation electrodes 80 are also described in US Pat. No. 9,136,101 B2. The combination of the varying width of the strip electrode 80 and the variation in the distance between the first and second ion-optical mirrors 50, 60 enables the reflection and spatial focusing of ions onto the detector 70, as well as maintaining a good temporal focus.

[0110] In use, the ion source 90, such as a pulsed ejection ion trap, injects ions into the first plurality of electrodes 51 of the first ion optical mirror 50 and then oscillates the ions between the first and second ion optical mirrors 50, 60. The angle of ion ejection from the ion source 90 and additional deflectors 100, 110 allow control of the energy of the ions in the drift direction such that ions are directed along the length of the electrodes 51, 61 of the first and second ion optical mirrors 50, 60 during oscillation, creating a zigzag trajectory. The entire ion flight path runs from the ion source 90 to the detector 70.

[0111] Fig. 2 shows an end view of the electrodes 51 of the first ion optical mirror 50 together with a portion of the inside of the vacuum chamber 20. The inside 21 of the vacuum chamber 20 in this preferred arrangement is a bottom surface of the vacuum chamber 20 (ie, a floor of the vacuum chamber).

[0112] How best Fig. 2, some of the electrodes of the first plurality of electrodes 51a, 51b, 51c, 51d are carried by a carrier 120 arranged between an inner side 21 of the vacuum chamber 20 and the respective electrode 51, 61. The carrier 120 allows a relative movement between at least a portion of the inner side 21 of the vacuum chamber 20 and the respective electrode 51. In the Fig. In the preferred embodiment illustrated in Figure 2, the support comprises a sphere 121 held in position by a flexible holder 122. The holder 122 can limit the lateral displacement of the sphere 121 received therein. The holder 122 can be formed from a flexible material or shaped to impart flexibility. The holder 122 can be formed from laser-cut and then folded sheet metal. Alternatively, the holder can be formed from Teflon. The sphere 121 can rotate, thereby allowing relative movement between the respective electrode 51, 61 it supports and the interior 21 of the vacuum chamber 20. For example, the sphere 121 allows the respective electrode 51, 61 it supports to translate both in its longitudinal direction and in its transverse direction relative to the interior 21 of the vacuum chamber 20.

[0113] In the Fig. 2, the holder 122 has an opening 123 configured to receive the ball 121 therein. In the preferred embodiment shown in Fig. 2, the interior 21 of the vacuum chamber includes a recess 21a that receives the ball 121 therein. The holder 122 preferably extends over the recess 21a formed in the interior 21 of the vacuum chamber 20 such that the holder contacts and / or is secured to the interior 21 of the vacuum chamber 20 on both sides of the recess 21a. The holder 122 may be generally planar. As discussed above, the flexibility of the holder 122 (being formed from a flexible material or shaped to impart flexibility) may allow the holder 122 to flex laterally to accommodate limited lateral translation of the ball 121 by rotation.

[0114] A schematic diagram for an alternative configuration of the holder 122 of the carrier 120 is shown in Fig. 3. In the Fig. 3, the holder 122 has an opening 123 configured to receive the ball 121 therein. The holder includes a generally planar member 124 defining the opening and includes one or more flexible projections 124a extending into the opening 123 and configured to flexibly retain the ball 121. The projections 124a may be radially disposed and / or extend around the ball. The holder further includes one or more lateral flanges 125 extending from the generally planar member 124 for securing the holder 122 to the interior surface 21 of the vacuum chamber 20. The one or more flanges 125 may be secured to the interior surface 21 of the vacuum chamber 20 within the recess 21a or on either side of the recess 21a.

[0115] The ball 121 is preferably formed of or coated with an electrically insulating material, such as a ceramic, such that the ball 121 is electrically insulated from the electrode it supports. The holder 122 can be formed, for example, from a metallic material.

[0116] Similar supports 120 can be used for the second plurality of electrodes 61, which Fig. 2 does not show.

[0117] How best Fig. 1 shows a plan view of the assembly when viewed from below, in which the holder 122 of the supports 120 and the inner surface 21 of the vacuum chamber 20 are not shown, one or more of the first and second pluralities of electrodes 51, 61 may include a plurality of spheres 121 used as supports 120. For example, a first sphere 121 may be positioned proximal to a first end of an electrode 51, 61 and spaced from a second sphere 121 positioned proximal to a second end of the electrode 51, 61 along the longitudinal direction of the electrode 51, 61. In this preferred arrangement, the electrode 51a of the first ion optical mirror 50 farthest from the second ion optical mirror 60 (i.e., the first electrode 51a) and the electrode of the first ion optical mirror 51e proximal to the second ion optical mirror 60 are supported by one or more of the supports 120 described above.Similarly, the electrode 61a of the second ion optical mirror 60 farthest from the first ion optical mirror 50 (i.e., the second electrode 61a) and the electrode 61e of the second ion optical mirror 60 proximal to the first ion optical mirror 50 are supported by one or more of the supports 120 described above.

[0118] How best Fig. 2, the electrodes of the first plurality of electrodes 51 may be mounted on a first pair of mounting rods 130, which may be formed from a ceramic material. The electrodes of the first plurality of electrodes 51 may include holes and / or slots with suitable tolerances configured to receive the mounting rod 130 such that contact surfaces of the mounting rods 130 with the electrodes 51, 61 mounted thereon are limited. Such an arrangement reduces friction between the electrodes 51, 61 and the mounting rods 130. In an optional alternative arrangement, the mounting rods 130 are formed from anodized aluminum rods, preferably coated with an electrically insulating material. Such an arrangement may result in reduced friction between the electrodes 51, 61 and the mounting rods 130. However, it is preferred to form the mounting rods 130 from ceramic materials.Each electrode of the first plurality of electrodes 51 is spaced from adjacent electrode(s) of the first plurality of electrodes by spacers 140 therebetween. The spacers 140 are referred to herein as electrode spacers 140. The electrode spacers 140 are preferably formed of an electrically insulating material, such as ceramic. An end stop 131 is preferably provided at each end of each mounting rod 130 to hold the electrodes 51 on the mounting rod 130. Between the end stops, a resilient member 132, for example, a spring, may also be mounted on the mounting rod. The resilient member 132 may be preloaded to maintain contact between each of the electrodes 51 and its adjacent spacers 140.The expansion or retraction of the electrodes 51 and / or the movement of the electrodes 51 along an axis parallel to the mounting rods 130 can be accommodated by expanding or contracting the elastic element 132. A similar arrangement can be used for the second plurality of electrodes 61, which . Fig. 2 does not show.

[0119] In the Fig. 1, each of the electrodes of the first and second plurality of electrodes 51, 61 is preferably thermally coupled to the inner side 21 of the vacuum chamber 20 by a respective flexible heat conductor 150. The flexible heat conductor 150 is best Fig. 4(a) and (b). Fig. Figure 4(a) shows an end view of part of the assembly of Fig. 1 and Fig. 2, comprising one electrode (the first electrode 51a) of the first plurality of electrodes 51, the flexible heat conductor 150 and a part of the inside 21 of the vacuum chamber 20. Fig. 4(b) shows a perspective view of the flexible heat conductor 150. The term "flexible" with respect to the flexible heat conductor 150 refers to the ability of the flexible heat conductor 150 to bend / move during normal use without breaking, such that the flexible heat conductor 150 does not hinder the movement of the electrode(s) 51, 61 relative to the inner surface 21 of the vacuum chamber 20.

[0120] Each flexible thermal conductor 150 may include a plurality of wires. The plurality of wires may be intertwined to form a flexible ribbon 151. Preferably, at least one upper surface of the plurality of wires is covered with an electrically insulating material, such as Teflon, which has been found to protect against voltage breakdown without significantly impacting vacuum quality. The plurality of wires may be completely surrounded by an electrically insulating material, such as Teflon. The one or more wires may be compressed and / or converged at their ends.

[0121] Each flexible heat conductor may include a first support 152 configured to connect the flexible heat conductor 150 to the respective electrode 51, 61, and a second support 153 configured to connect the flexible heat conductor to the interior 21 of the vacuum chamber 20. The heat-conducting wires 151 may extend between the first support 152 and the second support 153. The one or more wires may be compressed at their ends and / or merged into the first and / or second support 152, 153. For example, the first and second support 152, 153 may be formed from compressed and / or merged wires. The first support 152 and the second support 153 are typically formed from a heat-conductive material, such as copper. The first support 152 is preferably electrically insulated from the respective electrode 51, 61.In this arrangement, the first support 152 is electrically insulated from the respective electrode 51, 61 by a spacer 155 disposed between the first support 152 and the respective electrode 51, 61. The spacer 155 is referred to herein as an insulating spacer 155 and is preferably formed from an electrically insulating but thermally conductive material, such as ceramic. Aluminum nitride may be a preferred material for the insulating spacer 155 because, in addition to being electrically insulating, it has high thermal conductivity.

[0122] The flexible heat conductor 150 may be connected to the respective electrode 51, 61 using bolts / screws 156 that extend through an opening 152a in the first support 152 and through an opening (not shown) in the respective electrode 51, 61. The openings are preferably threaded. As Fig. As shown in Figure 4(a), at least the portion of the stud 156 received in the opening 152a in the first holder 152 may be surrounded by an electrically insulating layer 157 to electrically insulate the stud 156 from the flexible thermal conductor 150. The electrically insulating layer 157 may optionally also be thermally conductive.

[0123] The electrically insulating spacer 155 between the first support 152 of the flexible heat conductor 150 and the respective electrode 51, 61 and the electrically insulating layer 157 around the bolt 156 prevent voltage breakdown that could otherwise occur due to electrical contact between the wires of the flexible heat conductor 150 and the respective electrode 51, 61.

[0124] The second bracket 153 may be connected to the inside of the vacuum chamber using bolts / screws 158 extending through an opening 153a in the second bracket and a corresponding opening (not shown) in the inside 21 of the vacuum chamber 20.

[0125] How best Fig. 1, flexible heat conductors 150 are preferably connected proximally to each end of the respective electrode 51, 61 such that each electrode 51, 61 is thermally connected to the inner side 21 of the vacuum chamber 20 by two flexible heat conductors 150 spaced along the longitudinal direction of the electrode 51, 61. Preferably, the flexible heat conductors 150 have a cross-section selected to enable sufficient thermal coupling with the electrodes for efficient heating and cooling of the electrodes 51, 61 during annealing. Preferably, the flexible heat conductors 150 have a cross-sectional area of ​​20-400 mm2 which enables efficient heat transfer between the electrodes 51, 61 and the inner sides 21 of the vacuum chamber 20.

[0126] Fig. Figure 5 shows another arrangement not claimed which is used in the mr-TOF analyzer of Fig. 1 can be used.

[0127] A thermal compensation scheme is provided.

[0128] The electrodes are configured similarly to the electrode arrangement described in the first aspect of the invention. As described above, the electrodes 51, 61 form first and second opposing ion-optical mirrors 50, 60, spaced apart by a distance that defines a portion of the ion flight path therebetween. The first ion-optical mirror 50 comprises a first plurality of electrodes 51, and the second ion-optical mirror 60 comprises a second plurality of electrodes 61. The first electrode 51a is the electrode of the first plurality of electrodes 51 farthest from the second ion-optical mirror 60. The second electrode 61a is the electrode of the second plurality of electrodes 61 farthest from the first ion-optical mirror 50.

[0129] The electrodes 51, 61 are elongated in their longitudinal direction. A longitudinal direction can be defined as a direction generally aligned with the longitudinal axis of the electrode 51, 61. The transverse direction of the electrode is transverse, preferably perpendicular to the longitudinal direction. The first plurality of electrodes 51 and the second plurality of electrodes 61 are spaced apart from one another along a direction transverse to the longitudinal direction of the electrodes 51, 61.

[0130] A first connector 160 is connected to the first electrode 51a at a first connection point 161 and to the second electrode 61a at a second connection point 162. The first connector 160 is attached to the first and second electrodes 51a, 61a at the first and second connection points 161, 162 such that the first connector 160 cannot move relative to the electrodes 51a, 61a. The first connector 160 defines a first length between the first connection point 161 and the second connection point 162 at a reference temperature, which may be room temperature. The first connector 160 maintains the separation between the first and second electrodes 51a, 61a, which in turn maintains the separation / spacing between the first and second ion-optical mirrors 50, 60.The first connection point 161 and the second connection point 162 are fixed points on the electrodes 51a, 61a to which the first connector 160 is attached to the electrodes 51a, 61a. The first connector 160 has corresponding points thereon that correspond to the first and second connection points 161, 162 on the electrodes 51a, 61a. In this preferred arrangement, the first connector 160 is disposed below the first and second electrodes, and the first and second connection points 161, 162 are disposed on the undersides of the electrodes 51a, 61a. The first connector 160 is connected to the first and second electrodes at the first and second connection points, preferably using locating pins received in corresponding openings in the electrodes.Alternatively, in an optional arrangement, the first connector 160 may be connected to the first and second electrodes using bolts or clamps at the first and second connection points. Although the first and second connection points 161, 162 are shown as being located on the undersides of the first and second electrodes 51a, 61a, respectively, they may instead be provided at outer edges of the respective electrodes 51a, 61a. For example, the first connection point 161 may be located at the outer edge of the first electrode 51a (i.e., at the edge extending along the longitudinal direction of the first electrode 51a, which is located distal from the second electrode 61). Similarly, the second connection point 162 may be located at the outer edge of the second electrode 61a (i.e., at the edge extending along the longitudinal direction of the second electrode 61a, which is located distal from the first electrode 51a).In such an arrangement, the connector 160 may be indirectly coupled to the first and second electrodes 51a, 61a, such as with one or more clamps and / or mounts. For example, as shown in FIG. Fig. As shown in Figure 11, the connector 160 may be indirectly coupled to the first electrode 51a using a connector pin 300 having a first end 301 clamped by an electrode clip 310 attached to the outer edge of the first electrode 51a, and a second end 302 received and clamped in a through-hole 163 formed in a first end 164 of the connector 160. The first end 164 of the connector 160 is disposed proximal to the first electrode 51a. The electrode clip 310 may be formed from the first and second parts 310a, 310b, which may be complementary. The first part 310a may be attached to the outer edge of the first electrode 51a, for example with adhesive, and the second part may be coupled to the first part using one or more fasteners, referred to herein as a first fastener 311, such as screws / bolts.The first and second parts 310a, 310b may be configured to receive the connecting pin 300 therebetween when assembled. As shown. Fig. 11 shows, by tightening the first fastening 311, the connecting pin 300 can be clamped between the first and second parts 310a, 310b of the electrode clamp 310. As Fig. As shown in Figure 11, the through-hole 163 is configured to receive the connecting pin 300 therein and has an adjustable diameter. The diameter of the through-hole 163 can be reduced during assembly to clamp the connecting pin 300 within the through-hole 163. The diameter of the through-hole 163 can be adjusted by changing the width of a slot 165 formed in the connector 160 where the slot 165 intersects the through-hole 163. The width of the slot 165 can be adjusted by one or more fasteners, referred to herein as a second fastener 321, that bridge the slot 165 (i.e., extend across the slot 165). Tightening the second fastener 321 can reduce the width of the slot 163 and thus reduce the diameter of the through hole 163, thereby clamping the connecting pin 300 in the through hole 163. In the Fig. In the specific embodiment shown in Figure 11, the first fastener 311 is a pair of screws and the second fastener 321 is a single screw. As Fig. 11, the first fastener 311 can exert a clamping force on the first end 301 of the connecting pin 300 that is perpendicular to the clamping force exerted on the second end 302 of the connecting pin 300 by the second fastener 312 (in the tightened state). Fig. 11, the first connection point 161 is a point on the outer edge of the electrode 51a proximal to the electrode terminal 310. As Fig. As shown in Figure 11, the electrode clamp 310 is located on the outer edge of the first electrode 51a. This is advantageous because the electrode clamp 310 would be easily accessible for tightening with a wrench, compared to an arrangement in which the means used to connect the first electrode 51a and the first connector 160 are positioned on undersides of the first electrode 51a. It is also preferable, in terms of ease of assembly, to use clamps and / or retainers to secure the first connector to the first electrode 51a, compared to a dowel pin and a corresponding opening in the first electrode 51a. Furthermore, the movement / play of the dowel pin within the opening can lead to undesirable friction between the dowel pin and the first electrode 51a.The connector 160 can be connected to the second electrode 61a in a similar manner using another electrode terminal 310, a connecting pin 300, and a slot formed in a second end of the connector 160 proximal to the second electrode 61a.

[0131] The first connector 160 has a longitudinal direction that extends transversely (i.e., not parallel) to the longitudinal direction of the electrodes 51, 61, such that the connector extends across the space between the first and second ion-optical mirrors 50, 60. The longitudinal direction of the first connector 160 is arranged substantially perpendicular to the longitudinal direction of the electrodes 51 of the first ion-optical mirror 50. Substantially perpendicular refers to an angle of approximately 90°. The angle between the longitudinal direction of the electrodes 61 of the second ion-optical mirror 60 and the first connector 160 is less than 90°, preferably 85 to 89.99°, more preferably 89.90-89.98°. In this arrangement, the first connector 160 is shaped as a rod with a circular cross-section.

[0132] In the Fig. In the preferred arrangement shown in Figure 5, the electrode assembly further comprises a second connector 170 spaced from the first connector 160 and connected to the first electrode 51a at a third connection point 171 and to the second electrode 61a at a fourth connection point 172. The second connector 170 is substantially parallel to the first connector 160. The second connector 170 is spaced from the first connector 160 along the longitudinal direction of the electrodes 51, 61. The second connector 170 is configured similarly to the first connector 160, as discussed above.

[0133] The third connection point 171 is preferably aligned with the first connection point 161 along the longitudinal axis of the first electrode 51a. The fourth connection point 172 is preferably aligned with the second connection point 162 along the longitudinal axis of the second electrode 61a.

[0134] As discussed above, a change in temperature results in expansion / contraction of the mass analyzer's electrodes 51, 61. This, in turn, causes a change in the flight path length both within and between the spaced electrodes 51, 61 of the mass analyzer. For example, without the connector(s) 160, 170 in place, as the electrodes expand, the flight path within the electrodes 51, 61 would increase due to the increased width of the electrodes 51, 61 and the increased distance between the first and second ion optical mirrors 50, 60. This change in flight path length, in turn, results in a change in the total flight time for an ion and, therefore, a change in the m / z ratio of an ion detected by the mass analyzer (i.e., a shift in the m / z ratio per Kelvin).

[0135] However, with connectors 160, 170 in place, this shift in the m / z ratio per Kelvin is compensated. Indeed, with the connector(s) 160, 170 in place, an increase in the width of the electrodes 51, 61 due to their thermal expansion would cause the proximal edges of the spaced electrodes 51, 61 to approach each other, thereby reducing the distance between the first and second ion-optical mirrors 50, 60. However, the thermal expansion of the connector(s) 160, 170 increases the distance between the first and second connection points 161, 612 (and the third and fourth connection points 171, 172) to compensate for the increased width of the electrodes 51, 61, which would otherwise reduce the distance between the first and second ion-optical mirrors 50, 60. Accordingly, the connector(s) 160, 170 substantially maintain the distance between the first and second ion optical mirrors 50, 60.

[0136] Each electrode 51, 61 therefore has a shift in the m / z ratio per Kelvin, which can be determined based on the thermal expansion coefficient of the material from which it is formed, its dimensions, its geometry and its respective connection point 161, 162, 171, 172.

[0137] The material of the first and second connectors 160, 170, the positions of the first, second, third and fourth connection points 161, 162, 171, 172, the length defined by the first connector 160 between the first and second connection points 161, 162 at a reference temperature (i.e., the first length), and the length defined by the second connector 170 between the third and fourth connection points 171, 172 at the reference temperature (i.e., the second length) are selected such that the shift in the m / z ratio of the connectors 160, 170 per Kelvin can compensate for the shift in the m / z ratio of preferably all electrodes of the first and second plurality of electrodes 51, 61 per Kelvin.

[0138] The compensation may be such that a sum of the shift of the m / z ratio of the connectors 160, 170 and all electrodes 51, 61 of the first and second plurality of electrodes per Kelvin is less than ±10 ppm / K, preferably less than ±5 ppm / K, more preferably less than ±3 ppm / K, even more preferably less than ±2 ppm / K, most preferably less than ±1 ppm.

[0139] Given the geometry of the connectors 160, 170 and the electrodes 51, 61 (i.e., since the longitudinal direction of the connectors 160, 170 extends parallel to the spacing between the first and second plurality of electrodes 51, 61, but transverse to the longitudinal direction of the electrodes 51, 61), the connectors 160, 170 are formed from a material having a lower thermal expansion coefficient than the material used to form the electrodes 51, 61 to provide thermal compensation. The thermal expansion coefficient of the connectors 16, 170 may be ≤ 1 / 2 of the thermal expansion coefficient of the electrode(s) 51, 61, more preferably ≤ 1 / 5 of the thermal expansion coefficient of the electrode(s) 51, 61, most preferably ≤ 1 / 10 of the thermal expansion coefficient of the electrode(s) 51, 61.

[0140] Preferably, the connectors 160, 170 are formed from Invar having a thermal expansion coefficient of approximately 1-2 ppm / K, preferably 1.2 ppm / K, and / or the electrodes are formed from aluminum having a thermal expansion coefficient of approximately 20-30 ppm / K, preferably 25 ppm / K.

[0141] The majority of the compensation can be achieved by taking into account only the shift in the m / z ratio of the electrodes of the first and second pluralities of electrodes 51, 61 per Kelvin. The material of the connectors 160, 170, the positions of the first, second, third and fourth connection points 161, 162, 171, 172, the length defined by the first connector 160 between the first and second connection points 161, 162 at a reference temperature (the first length) and the length defined by the second connector 170 between the third and fourth connection points 171, 172 at the reference temperature (the second length) can be selected to compensate for the shift in the m / z ratio of other components of the analyzer in addition to the electrodes, e.g. B. the ion source 90, the detector 70 and / or the spacers 140 per Kelvin between the electrodes (electrode spacers 140), etc.All of these components expand / contract with a change in temperature, resulting in a change in the ion trajectory through them and a resulting change in the m / z shift measured for an ion. Therefore, each of these components has an associated shift in the m / z ratio per Kelvin, which can be determined based on the thermal expansion coefficient of the material from which they are formed, their geometry, and their dimensions.

[0142] For example, the material of the first and second connectors 160, 170, the positions of the first, second, third and fourth connection points 161, 162, 171, 172, the length defined by the first connector 160 between the first and second connection points 161, 162 at a reference temperature, and the length defined by the second connector 170 between the third and fourth connection points 171, 172 at the reference temperature can be selected such that the shift in the m / z ratio of the connectors 160, 170 per Kelvin can compensate for the shift in the m / z ratio of preferably all electrodes of the first and second plurality of electrodes 51, 61 and the electrode spacers 140 per Kelvin.

[0143] The compensation may be such that a sum of the shift of the m / z ratio of the connectors 160, 170, all electrodes 51, 61 of the first and second plurality of electrodes and the electrode spacers 140 per Kelvin is less than ±10 ppm / K, preferably less than ±5 ppm / K, more preferably less than ±3 ppm / K, even more preferably less than ±2 ppm / K, most preferably less than ±1 ppm / K.

[0144] As a further example, the material of the first and second connectors 160, 170, the positions of the first, second, third and fourth connection points 161, 162, 171, 172, the length defined by the first connector 160 between the first and second connection points 161, 162 at a reference temperature, and the length defined by the second connector 170 between the third and fourth connection points 171, 172 at the reference temperature can be selected such that the shift in the m / z ratio of the connectors 160, 170 per Kelvin can compensate for the shift in the m / z ratio of preferably all electrodes of the first and second plurality of electrodes 51, 61, the electrode spacers 140, and the ion source 90 and the detector 70 per Kelvin.

[0145] The compensation may be such that a sum of the shift of the m / z ratio of the connectors 160, 170, all electrodes 51, 61 of the first and second plurality of electrodes and the electrode spacers 140 per Kelvin is less than ±10 ppm / K, preferably less than ±5 ppm / K, more preferably less than ±3 ppm / K, even more preferably less than ±2 ppm / K, most preferably less than ±1 ppm.

[0146] As discussed above, the first plurality of electrodes 51 is inclined relative to the second plurality of electrodes 61. The angle of inclination in this arrangement may be approximately 0.02-0.1°. The length defined by the second connector 170 between the third connection point 171 and the fourth connection point 172, the positions of the third and fourth connection points 171, 172, and the material of the second connector 170 may be selected such that the angle of inclination is maintained during temperature changes. Preferably, the second connector 170 is formed of the same material as the first connector 160. The length of the second connector 170 between the third and fourth connection points 171, 172 at a reference temperature (i.e., the second length) differs from the length of the first connector 160 between the first and second connection points 161, 162 at the reference temperature (i.e.,the first length) to account for the angle of inclination between the first and second pluralities of electrodes 51, 61. For example, upon a temperature change, the first and second connectors 160, 170, if formed of the same material, expand / contract proportionally to one another, thereby maintaining the angle of inclination between the first and second pluralities of electrodes 51, 61. The angle of inclination is preferably maintained within ±0.01°, most preferably within ±0.001°, after thermal expansion of the electrodes 51, 61 and the connectors 160, 170. In an arrangement in which the first and second connectors 160, 170 are each clamped to the outer edges of the respective electrode 51, 61, as shown in FIG. Fig. As shown in Figure 11, the tilt angle can be achieved by inserting a spacer (not shown), referred to herein as a tilt spacer, between the electrode terminal 310 (in particular, the first part 310a of the electrode terminal 310) and the outer edge of the respective electrode 51, 61. The thickness of the tilt spacer can be selected to achieve the desired tilt angle. The tilt spacer can be, for example, a metal disc.

[0147] The second connector 170 is preferably attached to the first connector 160 only via the first and second electrodes 51a, 61a. In other words, there is preferably no direct connection between the first and second connectors 160, 170. Consequently, upon thermal expansion of the electrodes 51, 61 in their longitudinal direction, the distance between the first and second connectors 160, 170 increases to accommodate this expansion, thereby preventing bending of the electrodes 51, 61.

[0148] The second connector 170 may be attached to the inside of the vacuum chamber at a position between the third and fourth connection points 171, 172, preferably equidistant between the third and fourth connection points 171, 172. In this preferred arrangement, the second connector 170 is attached to the inside 21 of the vacuum chamber 20 with minimal contact at an attachment point 180. For example, the second connector 170 may be attached to the inside 21 of the vacuum chamber 20 with a locating pin received in a corresponding opening in the inside 21 of the vacuum chamber 20. As another example, the second connector 170 may be attached to the inside 21 of the vacuum chamber 20 at the attachment point 180 using a clamp that clamps the second connector 170 to the inside 21 of the vacuum chamber. The clamp may be screwed to the inside 21 of the vacuum chamber 20.By using a clamp, the second connector 170 can be secured to the inside 21 of the vacuum chamber 20 without creating a hole or slot in the second connector 170, which could otherwise weaken the connector 170. The clamp can also enable a more rigid connection between the second connector 170 and the inside 21 of the vacuum chamber 20. The clamp and the second connector 170 can be made of the same material, which can avoid / reduce stress or friction that could otherwise be generated due to differential thermal expansion / contraction of the clamp and the second connector 170. For example, the second connector 170 and the clamp used to secure the second connector 170 to the inside 21 of the vacuum chamber at the attachment point 180 can be formed from Invar with a thermal expansion coefficient of approximately 1-2 ppm / K, preferably 1.2 ppm / K.The inner side 21 is preferably the bottom surface of the vacuum chamber 20. The first connector 160 can move relative to the second connector 170 due to the expansion of the electrodes 51, 61 along their longitudinal direction, but drifting of the electrode assembly as a whole within the vacuum chamber 20 is prevented due to the connection of the second connector 170 to the inner side 21 of the vacuum chamber 20 at the attachment point 180.

[0149] The connectors 160, 170 are preferably received in trenches (recesses or grooves) (not shown) formed within the interior 21 of the vacuum chamber 20, which is preferably the underside of the vacuum chamber. The trenches may extend along portions of the interior 21 of the vacuum chamber 20 below the electrodes 51, 61, such that the connectors 160, 170 do not contact the interior 21 of the vacuum chamber 20 except at and / or around the attachment point 180, such that the attachment point 180 is not located within the trenches. Accordingly, the connectors 160, 170 cannot support the electrodes 51, 61. Fig. 11, one or more flexible supports 350 may be provided around at least a portion of the exterior of each of the connectors 160, 170 to prevent direct contact between the exterior of each of the connectors 160, 170 and the trenches during assembly (i.e., before the connectors 160, 170 are attached to the respective electrodes 51, 61). The flexible supports 350 may be configured to support the respective connector 160, 170 during assembly prior to connecting the connectors 160, 170 to the respective electrodes 51, 61. The flexible supports are formed from a flexible material or shaped to impart flexibility such that they allow and / or do not impede thermal expansion or contraction of the connectors 160, 170. The flexible supports can be made of laser-cut and then folded sheet metal, such as folded aluminum sheet.The flexible carrier(s) 350 may extend around the entire circumference of the respective connector 160, 170 or around a portion of the circumference of the respective connector 160, 170 that would otherwise contact the trench during assembly prior to connecting the connector 160, 170 to the electrodes 51, 61. As best . Fig. As shown in Figure 6, the connectors 160, 170 may be connected to the electrodes 51, 61 via spacers 190, referred to herein as connector spacers 190, which are arranged therebetween such that the connectors 160, 170 are spaced from the electrodes 51, 61. The connector spacers 190 may be formed from an electrically insulating material, such as a ceramic, such that the connector spacers 190 may be electrically insulated from the respective electrode 51, 61. Alternatively, the connectors 160, 170 may be connected directly to the electrodes 51, 61.

[0150] How Fig. As shown in Figure 6, in a further embodiment not claimed, the electrodes of the first plurality of electrodes 51 may be mounted on a first pair of mounting rods 130, which may be formed from a ceramic material. This arrangement is discussed in relation to the first aspect of the invention for the first and second pluralities of electrodes 51, 61.

[0151] The features of the first aspect of the invention can be combined with further features mentioned here. For example, Fig. 7 is a plan view from below of an arrangement used in the Fig. 1. The assembly comprises the first and second ion-optical mirrors 50, 60 described in both the first and further unclaimed embodiments, the supports 120 and flexible heat conductor 150 described in accordance with the first aspect, and the connectors 160, 170 described in accordance with further unclaimed embodiments.

[0152] In the arrangement of Fig. 7, the electrode(s) are thermally coupled to the interior 21 of the vacuum chamber 20 by the flexible heat conductors 150 for efficient heat transfer during the bakeout. This improves the efficiency of the outgassing process during the bakeout and shortens the time required to cool the analyzer after heating, so that it is ready for use. The supports 120 supporting the electrodes 51, 61 allow relative movement between the interior of the vacuum chamber 20 and the electrodes 51, 61. Consequently, stress and frictional forces on the electrodes 51, 61 due to thermal expansion / contraction of the vacuum chamber 20 due to heating and cooling of the vacuum chamber 20 during the bakeout are minimized.In fact, both the electrodes 51, 61 and the inner surface 21 of the vacuum chamber 20 can freely expand / contract with a temperature change without affecting the thermal efficiency between the inner surface 21 of the vacuum chamber 20 and the electrodes 51, 61.

[0153] Furthermore, since the supports 120 allow relative movement between the inner surface 21 of the vacuum chamber 20 and the electrodes 51, 61, the thermal expansion / contraction of the vacuum chamber 20 does not significantly affect the thermal compensation scheme. Indeed, the thermal expansion / contraction of the electrodes 51, 61 and the thermal expansion / contraction of the connectors 160, 170 are not significantly affected by the thermal expansion / contraction of the vacuum chamber 20. This is because the electrodes 51, 61 are supported by supports 120, which allow relative movement between the electrodes 51, 61 and the inner surface 21 of the vacuum chamber 20. The first connector 160 is not directly attached to the vacuum chamber 20. The second connector 170 is attached to the vacuum chamber 20 by only minimal contact (e.g., by a dowel pin) in a position (attachment point 180) between the first and second ion optical mirrors 50, 60.Therefore, the expansion / contraction of the vacuum chamber 20 during heating and cooling during bakeout does not result in a load on the electrodes 51, 61 of the analyzer.

[0154] As discussed above, the connectors 160, 170 may be connected to the electrodes 51, 61 via connector spacers 190 disposed therebetween, such that the connectors are spaced from the electrodes 51, 61. The spacers 190 are formed of an electrically insulating material, such as ceramic. The spacers 190 are positioned at the first, second, third, and fourth connection points 161, 162, 171, 172. As discussed above, the connectors 160, 170 are received in trenches formed in the interior 21 of the vacuum chamber 20. The depth of the trenches is such that the connectors 160, 170 do not contact the interior of the vacuum chamber 20 except at the attachment point 180. Therefore, although the connectors 160, 170 extend below the electrodes 51, 61 in this arrangement, the connectors 160, 170 do not support the electrodes 51, 61.Instead, the electrodes 51, 61 can be fully supported by the supports 120, which allow relative movement between the electrodes 51, 61 and the interior 21 of the vacuum chamber 20. Accordingly, the presence of the connectors 160, 170 does not reduce the functionality of the supports 120. The flexible heat conductors 150 can have a cross-sectional area between 20 and 400 mm. 2which enables efficient heat transfer without causing bending of the connectors 160, 170. One or more flexible heat conductors 150 may be connected between the connector(s) 160, 170 and the interior 21 of the vacuum chamber 20, such that the flexible heat conductors 150 enable heat transfer between the connector(s) 160, 170 and the interior 21 of the vacuum chamber. It may be advantageous to use multiple flexible heat conductors 150 connected to each connector 160, 170 if the connectors are formed from a material with poor thermal conductivity, such as Invar.

[0155] Fig. Figure 8 is a schematic plan view of a portion of an outgassing device 200 for removing contaminants from surfaces 21 by heating and then cooling the surfaces within a vacuum chamber 20 housing a time-of-flight mass analyzer 30. The device 200 includes one or more cooling channels 210, the cooling channels 210 arranged for cooling surfaces within the vacuum chamber 20 by transporting a cooling medium through the cooling channel(s) 210, a heater (not shown) arranged for heating the surfaces 21 within the vacuum chamber 20, and an insulating material 220 surrounding an exterior of the vacuum chamber 20.

[0156] The device can be arranged in the arrangement of Fig. 1. In other words, the arrangement of Fig. 1 may comprise an insulating material 220 surrounding the outside of the vacuum chamber 20, cooling channels 210 arranged to cool surfaces 21 within the vacuum chamber 20 by transporting a cooling medium through the cooling channels 210, and a heater arranged to heat the surfaces within the vacuum chamber 20.

[0157] How best in Fig. As shown in Figure 8, the insulating material 220 surrounds most of the exterior of the vacuum chamber 20 and preferably surrounds the entire exterior of the vacuum chamber. The insulating material 220 is preferably a foam material, for example, polyurethane or polypropylene foam. The heater (not shown) is preferably positioned between the insulating material 220 and the exterior of the vacuum chamber 20. The heater may be a heating element that may be attached to an exterior of the vacuum chamber 20, for example, by screws.

[0158] The Fig. The arrangement shown in Figure 8 comprises two cooling channels 210, referred to herein as first and second cooling channels 210a, 210b. In this preferred arrangement, each cooling channel 210 is formed as one or more recesses and / or grooves formed in the outer wall of the vacuum chamber 20, preferably the lower outer wall of the vacuum chamber. Each cooling channel 210 has a depth extending through a portion of the thickness of the outer wall of the vacuum chamber 20, such that the cooling channel is formed in the outer side of the vacuum chamber wall and the inner sides of the vacuum chamber 20 remain intact. The insulating material 220 surrounding the outer side of the vacuum chamber 20 also covers the recesses and / or grooves forming the cooling channels 210.

[0159] In the preferred arrangement of Fig. 8, the first cooling channel 210a extends between a first edge 22 of the bottom wall 21 and a second edge 23 of the bottom wall 21, the first and second edges 22, 23 being substantially perpendicular to each other. The second cooling channel 210b extends between a third edge 24 of the bottom wall and a second edge 23 of the bottom wall 21, the third and second edges 24, 23 being perpendicular to each other. In this preferred arrangement, the first and second cooling channels 210a, 210b are curved. By using curved instead of straight cooling channels 210, the space occupied by the cooling channels 210 is reduced, such that the remaining space can be used more efficiently, for example, to position vacuum pumps therein.Alternatively, the first and second cooling channels 210 may extend between the first and third edges 22, 24 or the second and fourth edges 23, 25 of the bottom wall 21, the fourth and second edges 23, 25 being parallel to each other, such that the cooling channels 210 are formed as straight channels. In this preferred arrangement, the inlet 230 of the first cooling channel 210a is formed at the first edge 22 of the bottom wall 21, and the outlet 231 of the first cooling channel 210a is formed at the second edge 23 of the bottom wall 21. The inlet 232 of the second cooling channel 210b is formed at the third edge 24 of the bottom wall 21, and the outlet 233 of the second cooling channel 210b is formed at the second edge 23 of the bottom wall 21.

[0160] The cooling channels 210 can be configured to actively cool the surfaces within the vacuum chamber 20 during use. In this preferred arrangement, the cooling medium used is a gas (preferably air). To achieve active cooling, a fan 240 is provided near the inlet 230, 232 of each cooling channel 210 to drive the cooling medium through the respective cooling channel 210. In an alternative arrangement where a liquid coolant medium is provided, a pump can instead be used to drive the coolant through the respective cooling channel 210. Normally, the flow of the cooling medium through the cooling channels 210 can be restricted except when the fans 240 and / or pumps are activated.

[0161] In this preferred arrangement, a heat sink 250 is provided in each cooling channel 210, preferably downstream of the fan 240. The heat sink 250 is preferably formed from extruded aluminum or copper. The heat sink 250 may be attached to the recess / groove forming each cooling channel 210, for example, by adhesive and / or bolts. The heat sink 250 is preferably formed from extruded aluminum or copper and configured to receive the cooling medium flowing through the cooling channel 210 during use.

[0162] Vacuum pumps are arranged in Fig. 8, but may be positioned between the first and second cooling channels 210a, 210b. The vacuum pumps may be partially thermally decoupled from the vacuum chamber 20, with a steel plate arranged at the contact surfaces between the vacuum pumps and the vacuum chamber 20.

[0163] The device may further comprise a controller (not shown) configured to control the activation and deactivation of the heater (not shown) and the activation and deactivation of the fans 240. The controller is configured to activate the fans 240 after the heater is deactivated. Therefore, in use, when performing outgassing to remove contaminants from surfaces within the vacuum chamber 20 (i.e., during bakeout), the controller activates the heater such that the heater heats the surfaces 21 within the vacuum chamber 20. The efficiency of heating the surfaces within the vacuum chamber 20 is improved due to the use of the insulating material 220 surrounding the exterior of the vacuum chamber 20. For example, to achieve outgassing in an mr-TOF analyzer with a 20 m flight path, the heater only requires a power supply of less than 1 kW due to the improved efficiency achieved.After the contaminants have been removed from the surfaces 21 within the vacuum chamber 20, the controller shuts down the operation of the heater and activates the fans 240 such that the flow of the cooling medium (in this case, air) is driven through the cooling channels 210, thereby actively cooling the surfaces 21 within the vacuum chamber 20. This therefore improves the efficiency of cooling the surfaces 21 within the vacuum chamber 20 such that the time required for outgassing is reduced.

[0164] This arrangement is also advantageous for general use of the time-of-flight mass analyzer (i.e., not just during bakeout (outgassing). For example, insulation 220 also protects the mass analyzer from ambient temperature changes during use.

[0165] According to Fig. The concept described in 8 is equally applicable to any type of mass analyzer.

[0166] The above-described inventive concept of the first aspect of the present invention may be used together in any combination of features. Experimental data

[0167] The data presented below in Table 1 demonstrate the thermal compensation achieved by a setup using a mass analyzer, where the mass analyzer is an mr-TOF analyzer. In other words, the setup included a setup similar to that described in Fig. 5 and Fig. 6, which uses a connector 160. In this arrangement, as described above, the analyzer comprises a first ion optical mirror 50 including a first electrode 51a, and a second ion optical mirror 60 including a second electrode 61b. The second ion optical mirror 60 is spaced from the first ion optical mirror 50 by a distance defining a portion of an ion flight path therebetween. A connector 160 was used, which is connected to the first electrode 51a at a first connection point 161 and to the second electrode at a second connection point 162. The first ion optical mirror 50 comprises a first plurality of electrodes 51, and the second ion optical mirror 60 comprises a second plurality of electrodes 61. The first electrode 51a is the electrode of the first plurality of electrodes 51 that is farthest from the second plurality of electrodes 61.The second electrode 61a is the electrode of the second plurality of electrodes 61 farthest from the first plurality of electrodes 51. The electrodes of the first plurality of electrodes 51 are separated by intermediate spacers 140, described above as electrode spacers 140. The electrodes of the second plurality of electrodes 61 are separated by intermediate spacers 140. In the arrangement used to obtain the data in Table 1, the distance between the first and second ion-optical mirrors 50, 60 used was 8 mm.

[0168] The values ​​for the shift in m / z per Kelvin listed in the following table were determined by simulating ion trajectories within the analyzer system using the MASIM3D software. In the table below, electrodes 51, 61 are labeled M0, M1, M2, M3, and M4. As indicated in the table below, electrodes 51, 61 of the first and second plurality of electrodes have the greatest influence on the total m / z shift per Kelvin. The spacers 140 between electrodes 51, 61 have only a negligible effect on the total m / z shift per Kelvin.

[0169] In this arrangement, a connector 160 is used which is as described in the Fig. 6 and Fig. 7 and is formed of Invar with a length of 632 mm between the first and second connection points. In other words, the length of the connector 160 between its center and the first connection point 161 was 318 mm, and the length of the connector between its center and the second connection point 162 was 318 mm. The sum of the shift of the m / z ratio per Kelvin of the electrodes 51, 61, the spacer 140, and the connector 160 is 2.69 ppm / K. Accordingly, in this arrangement, the compensation achieved by the connector 160, which is as shown in Fig. 6 and Fig. 7, such that the total shift of the m / z ratio per Kelvin is reduced to 2.69 ppm / K. Komponente Länge / mm Einfluss auf die m / z-Zuordnung ppm / K Invar-Stab (1,5 ppm / K) ± 318 (gesamt632) 2,98 Aluminiumelektrode(22 ppm / K) M4 28 2,94 Aluminiumelektrode M3 16 -1,98 Aluminiumelektrode M2 16 -1,68 Aluminiumelektrode M1 46 1,60 Aluminiumelektrode M0 37 -1,31 AIN (4,5 ppm / K)Abstandshalter M4 / M3 8 0,00 AIN-Abstandshalter M3 / M2 8 0,19 AIN-Abstandshalter M2 / M1 30 0,12 AIN-Abstandshalter M1 / M0 24 -0,16 Gesamt 2,69

[0170] It was determined that by using an Invar connector 160 with a length of 678 mm between the first and second connection points, full compensation would be achieved such that the total shift in the m / z ratio per Kelvin is reduced to 0. (i.e., using a connector 160 in which the length of the connector 160 between its center and the first connection point 161 was 339 mm and the length of the connector 160 between its center and the second connection point 162 was 339 mm).

[0171] Fig. Figure 9 shows the measured m / z variation with temperature for an arrangement using the first aspect of the invention, wherein the mass analyzer is an mr-TOF analyzer. In other words, the arrangement comprised an arrangement similar to that shown in Fig. 7, which also have the characteristics of Fig. 8. In other words, the assembly included the supports 120 and flexible heat conductors 150 described in the first aspect, the connectors 160, 170 described in further embodiments, and the insulating material 220, the heating and cooling channels 210 described in further embodiments.

[0172] The mr-TOF mass analyzer was about 1 m 2large and had a total ion flight path length of 21 m. The vacuum chamber 20 was heated with 50 W heating power over two 24-hour cycles. The m / z of the fluoranthene ion was measured over the 48 hours of the experiment, and its deviation from its initial value (i.e., before heating) was plotted. The temperature change of the vacuum chamber 20 in Kelvin was measured by PT100 sensors mounted on the vacuum chamber 20. The vacuum chamber 20 achieves a thermal drift of almost +2.5 K, and the resulting shift in the m / z ratio is +3.4 ppm. This corresponds to a shift in the m / z ratio per Kelvin of 1.4 ppm / K. There are anomalous changes in the m / z ratio shift that occur over minutes while the heater is activated / deactivated when copper heat sinks are provided in the cooling channels 210.It is believed that this anomalous change may reflect a load on the chamber 20 transmitted to the ion-optical mirrors 50, 60, or movement due to rapid heating of the electrodes 51, 61. There is also some delay between the m / z shift peaks and the vacuum chamber temperature peaks due to the time required for heat transfer to the electrodes 51, 61 of the ion-optical mirrors 50, 60 via the flexible heat conductors 150.

[0173] Fig. Figure 10 shows the effectiveness of heating and cooling this arrangement with a cycle typically used for annealing, i.e., performing outgassing. The cycle comprises 6 hours of heating, followed by continuous active cooling using cooling channels 210, through which air flows as the cooling medium. PT100 sensors were mounted on the vacuum chamber 20 and on four of the electrodes 51 of the first ion-optical mirror 50, designated M0 (ground), M1, M2, and M4. Fig.10, M4 has the highest temperature between 5 and 10 minutes, followed by M2, then M1, and then M0. The vacuum chamber has the lowest temperature. The lines for M1 and M0 intersect at approximately 10 minutes. From these data, it can be seen that this insulating material improves the efficiency of heating the vacuum chamber and the analyzer electrodes 51 therein, and the cooling channels improve the efficiency of cooling the electrodes 51 after heating. These data also show that the flexible thermal conductor 150 provides efficient thermal coupling of the electrodes 51 and the vacuum chamber 20. In fact, the temperature of all electrodes 51 and the vacuum chamber 20 exceeds 80°C during 14 hours and cools well below 30°C within this period. The final base pressure within the vacuum chamber 20, in which the mr-TOF mass analyzer is positioned, was determined at a suitable value of 3x10 -9 mbar recorded.

Claims

[1] Arrangement (10) comprising a vacuum chamber (20) and a time-of-flight mass spectrometer (30), wherein the time-of-flight mass spectrometer (30) is contained in the vacuum chamber (20), wherein the time-of-flight mass spectrometer (30) comprises a first electrode (51a) and a second electrode (61a), wherein the second electrode (61a) is spaced apart from the first electrode (51a) at a distance which defines a section of an ion flight path between them; wherein the arrangement (10) further comprises a first support (120) for supporting the first electrode (51a), wherein the first support (120) is arranged between an inner side (21) of the vacuum chamber (20) and the first electrode (51a); wherein the first support (120) is configured to allow relative movement between at least one section of the inside (21) of the vacuum chamber (20) and the first electrode (51a); wherein the vacuum chamber (20) is thermally coupled to the first and / or second electrode(s) by one or more flexible heat conductors (150), and wherein the inner side (21) of the vacuum chamber (20) and the first electrode (51a) are thermally coupled. [2] Arrangement (10) according to claim 1, wherein the arrangement (10) further comprises a second support for carrying the second electrode (61a), wherein the second support is arranged between the inside (21) of the vacuum chamber (20) and the second electrode (61a), wherein the second support is configured to allow relative movement between at least one section of the inside (21) of the vacuum chamber (20) and the second electrode (61a). [3] Arrangement (10) according to one of the preceding claims, wherein the inside (21) of the vacuum chamber (20) and the second electrode (61a) are thermally coupled. [4] Arrangement (10) according to any one of claims 1 to 3, wherein each flexible heat conductor (150) comprises one or more heat-conducting wires (151). [5] Arrangement (10) according to any one of claims 1 to 4, wherein each flexible heat conductor (150) comprises a first holder (152) configured to connect the flexible heat conductor(s) (150) to the respective electrode, and a second holder (153) configured to connect the flexible heat conductor(s) (150) to the inside (21) of the vacuum chamber (20). [6] Arrangement (10) according to claim 5, depending on claim 4, wherein the one or more thermally conductive wires (151) extend between the first support (152) and the second support (153), wherein the first support (152) and the second support (153) are thermally conductive. [7] Arrangement (10) according to claim 5 or 6, wherein the first holder (152) is electrically insulated from the respective electrode. [8] Arrangement (10) according to one of claims 5 to 7, further comprising a spacer (155) configured to space the first holder (152) and the respective electrode apart, wherein the spacer (155) is preferably made of an electrically insulating material. [9] Arrangement (10) according to one of claims 5 to 8, wherein a surface of the first holder (152) in contact with the respective electrode is electrically insulating. [10] Arrangement (10) according to one of the preceding claims, wherein the first and / or second support comprises a surface configured to support the respective electrode, wherein the surface is electrically insulating. [11] Arrangement (10) according to one of the preceding claims, wherein the first and / or second support enables a relative displacement of the respective electrode relative to at least one section of the inside (21) of the vacuum chamber (20). [12] Arrangement (10) according to claim 11, wherein the first and / or second support comprises one or more rotatable elements, each rotatable element having a curved surface configured to support the respective electrode thereon. [13] Arrangement (10) according to claim 12, wherein each rotatable element is a sphere (121), wherein the sphere (121) is received by a holder (122) such that the sphere (121) is rotatable relative to the holder (122), and wherein the holder (122) is coupled to the inside (21) of the vacuum chamber (20). [14] Arrangement (10) according to claim 12 or 13, wherein the inside (21) of the vacuum chamber (20) comprises a complementary recess (21a) for receiving each rotatable element. [15] Arrangement (10) according to claims 1 to 11, wherein the first support (120) and the second support are formed in one piece. [16] Arrangement (10) according to any one of claims 1 to 11, wherein the first (120) and / or second support comprises a lubricated layer, wherein the lubricated layer is electrically insulating, wherein preferably the first support (120) is a first section of the lubricated layer and the second support is a second section of the lubricated layer, wherein more preferably the first support (120) and the second support are formed in one piece. [17] Arrangement (10) according to any one of claims 1 to 11, wherein the first (120) and / or second support comprises a layer with a low coefficient of friction and is formed from an electrically insulating material, wherein preferably the first support (120) is a first section of the layer and the second support is a second section of the layer, wherein more preferably the first support (120) and the second support are formed in one piece. [18] Arrangement (10) according to any one of claims 1 to 11, wherein the first (120) and / or second support comprises one or more wires configured to suspend the respective electrode on the inside (21) of the vacuum chamber (20). [19] Arrangement (10) according to any one of claims 1 to 11, wherein the first (120) and / or second support comprises one or more springs extending between the inside (21) of the vacuum chamber (20) and the electrode(s). [20] Arrangement (10) according to one of the preceding claims, wherein the time-of-flight mass spectrometer (30) is a multiple reflection time-of-flight mass spectrometer, wherein the multiple reflection time-of-flight mass analyzer comprises a first ion-optical mirror (50) comprising at least the first electrode (51a) and a second ion-optical mirror (60) comprising at least the second electrode (61a), wherein the second ion-optical mirror (60) is spaced apart from the first ion-optical mirror (50) at a distance which defines at least the section of the ion flight path between them. [21] Arrangement (10) according to claim 20, wherein the first ion-optical mirror (50) comprises a first plurality of electrodes (51) spaced apart from each other, and / or wherein the second ion-optical mirror (60) comprises a second plurality of electrodes (61) spaced apart from each other. [22] Arrangement (10) according to any one of claims 1 to 19, wherein the time-of-flight mass spectrometer (30) is a multi-turn time-of-flight mass spectrometer, the multi-turn time-of-flight mass analyzer comprises a first electrostatic sector comprising at least the first electrode (51a) and a second electrostatic sector comprising at least the second electrode (61a), wherein the second electrostatic sector is spaced apart from the first electrostatic sector by a distance which defines at least the section of the ion flight path between them. [23] Arrangement (10) according to claim 22, wherein the first electrostatic sector comprises a first plurality of spaced-apart electrodes (51) and / or the second electrostatic sector comprises a second plurality of spaced-apart electrodes (61), wherein preferably the first electrode (51a) is the electrode of the first plurality of electrodes (51) furthest from the second electrostatic sector and / or wherein the second electrode (61a) is the electrode of the second plurality of electrodes (61) furthest from the first electrostatic sector. [24] Arrangement (10) according to claim 21, wherein the first electrode (51a) is the electrode of the first plurality of electrodes (51) furthest from the second ion-optical mirror (60) and / or the second electrode (61a) is the electrode of the second plurality of electrodes (61) furthest from the first ion-optical mirror (50). [25] Arrangement (10) according to one of the preceding claims, wherein the first electrode (51a) has a shift of the m / z ratio per Kelvin, wherein the second electrode (61a) has a shift of the m / z ratio per Kelvin, wherein the arrangement (10) further comprises a connector (160) which is connected to the first electrode (51a) at a first connection point (161) and to the second electrode (61a) at a second connection point (162), wherein the connector (160) has a shift of the m / z ratio per Kelvin, wherein the connector (160) defines a first length between the first and the second connection point (162) at a reference temperature; wherein the first length, the positions of the first and second connection points (161, 162) and the material of the connector (160) are selected to compensate for the sum of the shift of the m / z ratio per Kelvin in the first and second electrodes (51a, 61a). [26] Arrangement (10) according to claim 25, depending on one of claims 21, 23 or 24, wherein the first length, the positions of the first and second connection point (161, 162) and the material of the connector (160) are selected to compensate the sum of the displacement of the m / z ratio of all electrodes of the first plurality of electrodes (51) and the second plurality of electrodes (61) per Kelvin. [27] Arrangement (10) according to claim 26, wherein the compensation is such that the sum of the shift of the m / z ratio per Kelvin in the connector (160) and all electrodes of the first plurality of electrodes (51) and the second plurality of electrodes (61) is less than ±10 ppm / K, preferably less than ±5 ppm / K, more preferably less than ±3 ppm / K, even more preferably less than ±2 ppm / K, most preferably less than ±1 ppm / K. [28] Arrangement (10) according to claim 25, wherein the compensation is such that the sum of the displacement of the m / z ratio of the connector (160) and the first and second electrodes (51a, 61a) per Kelvin is less than ±10 ppm / K, preferably less than ±5 ppm / K, more preferably less than ±3 ppm / K, even more preferably less than ±2 ppm / K, most preferably less than ±1 ppm / K. [29] Arrangement (10) according to any one of claims 25 to 28, wherein a thermal expansion coefficient of the connector (160) is smaller than a thermal expansion coefficient of the electrode(s), wherein preferably the thermal expansion coefficient of the connector (160) is ≤ 1 / 2 of the thermal expansion coefficient of the electrode(s), wherein more preferably the thermal expansion coefficient of the connector (160) is ≤ 1 / 5 of the thermal expansion coefficient of the electrode(s), wherein most preferably the thermal expansion coefficient of the connector (160) is ≤ 1 / 10 of the thermal expansion coefficient of the electrode(s). [30] Arrangement (10) according to one of claims 25 to 29, wherein the connector (160) extends transversely to a longitudinal direction of the first electrode (51a), wherein the connector (160) preferably extends perpendicular to the longitudinal direction of the first electrode (51a). [31] Arrangement (10) according to one of claims 25 to 30, wherein the connector (160) is a first connector, wherein the analyzer further comprises a second connector (170) which is connected to the first electrode (51a) at a third connection point (171) and to the second electrode (61a) at a fourth connection point (172), wherein the second connector (170) defines a second length between the third and the fourth connection point (171, 172) at the reference temperature, wherein the second connector (170) is spaced apart from the first connector (160), wherein preferably the second connector (170) is parallel to the first connector (160). [32] Arrangement (10) according to claim 31, wherein the second connector (170) is spaced apart from the first connector (160) in a longitudinal direction of the first electrode (51a). [33] Arrangement (10) according to one of claims 31 to 32, wherein the longitudinal direction of the second electrode (61a) has an angle between 0 and 5 degrees to the longitudinal direction of the first electrode (51a), wherein the second length, the positions of the third connection point (171) and the fourth connection point (172) and a material of the second connector (170) are selected such that the angle between the first electrode (51a) and the second electrode (61a) is maintained within ±0.01°, preferably ±0.001°, after thermal expansion of the electrodes and connector. [34] Arrangement (10) according to one of claims 31 to 33, wherein the second connector (170) is attached to an inner side (21) of the vacuum chamber (20). [35] Arrangement (10) according to any one of claims 1 to 34, wherein the arrangement (10) further comprises: one or more cooling channels (210, 210a, 210b), wherein the cooling channels (210, 210a, 210b) are arranged to cool surfaces within the vacuum chamber (20) by transporting a cooling medium through the one or more cooling channels (210, 210a, 210b); a heater arranged to heat the surfaces inside the vacuum chamber (20); and an insulating material (220) that surrounds an outer surface of the vacuum chamber (20). [36] Arrangement (10) according to claim 35, wherein one or more cooling channels (210, 210a, 210b) extend around and / or through the vacuum chamber (20). [37] Arrangement (10) according to claim 35 or 36, wherein the heating element is located between the insulating material (220) and the outside of the vacuum chamber (20). [38] Arrangement (10) according to claims 35 to 37, wherein the one or more cooling channels (210, 210a, 210b) are surrounded by the insulating material (220). [39] Arrangement (10) according to any one of claims 35 to 38, wherein the one or more cooling channels (210, 210a, 210b) extend at least partially through the vacuum chamber (20) and / or at least partially around the outside of the vacuum chamber (20). [40] Arrangement (10) according to one of claims 35 to 39, wherein each of the cooling channels (210, 210a, 210b) extends between an inlet (230, 232) and an outlet (231, 233), wherein preferably the inlet (230, 232) and the outlet (231, 233) are apertures formed as recesses and / or apertures in one or more walls of the vacuum chamber (20). [41] Arrangement (10) according to one of claims 35 to 39, wherein each cooling channel (210, 210a, 210b) is formed as a recess within a wall of the vacuum chamber (20), wherein preferably each cooling channel (210, 210a, 210b) is formed as a recess in an outer wall of the vacuum chamber (20), wherein more preferably the recess formed in the outer wall of the vacuum chamber (20) is covered by the insulating material (220). [42] Arrangement (10) according to one of claims 35 to 39, wherein each cooling channel (210, 210a, 210b) is formed as a recess within an inner surface of the insulating material (220). [43] Arrangement (10) according to one of claims 35 to 40, wherein preferably each cooling channel (210, 210a, 210b) is formed by a tube. [44] Arrangement (10) according to any one of claims 35 to 43, wherein at least one of the cooling channels (210, 210a, 210b) comprises one or more cooling elements (250) configured to receive a cooling medium flowing through the cooling channel (210, 210a, 210b). [45] Arrangement (10) according to any one of claims 35 to 44, wherein at least one of the cooling channels (210, 210a, 210b) further comprises one or more fans (240) configured to drive the cooling medium through the cooling channel (210, 210a, 210b). [46] Arrangement (10) according to one of claims 35 to 45, further comprising a controller configured to control the activation and deactivation of the heater and / or the one or more fans (240), wherein the controller is preferably configured to activate the one or more fans (240) after deactivation of the heater.

Images