Vacuum system and detection device

Abstract

The invention relates to a vacuum system comprising a vacuum chamber and a detection device and to a detection device for a vacuum system. A vacuum system (1) comprises a vacuum chamber (10) with an outer wall (12). The outer wall includes a volume (15) that can be evacuated. The vacuum system (1) further comprises a detection device (20) having a detection element for detecting waves and / or particles. The detection device (20) is arranged outside the vacuum chamber (10). In this way, high-quality detection can be achieved with little technical effort.

Description

[0001] Vacuum system and detection device

[0002] Description

[0003] The invention relates to a vacuum system with a vacuum chamber and a detection device as well as a detection device for a vacuum system.

[0004] When detecting waves or particles, detection devices with detection elements are used. A detection element is an object that interacts with waves and / or particles, thus enabling the detection of the waves or particles. The detection element can comprise a solid or a liquid, for example, in the case of a scintillator. The detection element can comprise a gas container in which a gas or gas mixture can be arranged to detect the waves or particles. A vacuum chamber is provided through which the waves or particles to be detected can reach the detection device undisturbed.

[0005] For example, vacuum systems such as the SEQUOIA instrument at the SNS beam source in the USA, the LET instrument at the ISIS beam source in the UK, the NEAT instrument at the HZB in Berlin, or the T-REX instrument currently under construction at the ESS in Sweden are known for the detection of neutrons. These contain a vacuum chamber and a detection device with a gas container for holding a gas or gas mixture for detecting neutrons. A sample can be placed in the vacuum chamber. Neutrons from a neutron source fly to the sample and from there through the vacuum to the detection device located in the vacuum chamber. A sample environment and / or a gate valve (sealing container) can be present.

[0006] Figure 1 schematically shows a conventional vacuum system 1 with a vacuum chamber 10 defined by an outer wall 12. Located inside the vacuum chamber 10 is a detection device 20 with a detection element containing one or more gas containers 22. The emitted, scattered, or deflected waves or particles pass through the vacuum chamber 10 into the interior of the gas container 22 of the detection device. The gas or gas mixture contained in the gas containers 22 interacts with the emitted waves or particles to detect them. The outer wall 12 of the detection device 20 is designed on all schematically illustrated sides 25 such that it mechanically withstands the vacuum. The outer wall 12 of the detection device 20 can simultaneously be the wall defining the gas container 22.

[0007] A cable package 27 runs from the detection device 22 through the volume 15 to be evacuated and traverses the outer wall 12 of the vacuum chamber 10. In this way, for example, signals and / or a cooling medium can be exchanged between the detection device 20 and the environment outside the vacuum chamber 10. Not shown, but usually nevertheless present inside the vacuum chamber 10, is a sample environment in which a sample can be positioned to emit waves and / or particles. More precisely, the sample scatters or deflects the waves and / or particles after being bombarded or irradiated with them. Emitting therefore also means transmission in which existing waves and / or particles are merely scattered and / or deflected. This can be the case, for example, when neutrons are used and detected.

[0008] Figure 3 shows a perspective view of a conventional vacuum system 1 with a vacuum chamber 10 containing a volume 15 to be evacuated, defined by an outer wall 12. Ten detection devices 20 are arranged in the vacuum chamber 10. Each of the detection devices 20 comprises a gas container 22 and a processing unit 26. The respective processing units 26 are connected to the environment outside the vacuum chamber 10 via corresponding vacuum-tight lines.

[0009] Also shown are parts of a beam conditioning device 40, a beam stop 42 arranged opposite the beam conditioning device 40 for capturing the primary beams, and the sample environment 30 located in the beam path. A door 34 is also provided through which users can enter the vacuum chamber 10, for example, for servicing the detection devices 20. These vacuum systems are technically complex.

[0010] The object of the invention is to provide an advanced vacuum system and a detection device for such a system. In particular, the object of the invention is to reduce the technical complexity while maintaining high detection quality.

[0011] To achieve this objective, a vacuum system according to claim 1 and a detection device for a vacuum system according to the independent claim are provided. Advantageous embodiments are specified in the subclaims.

[0012] A vacuum system serves to solve this problem. The vacuum system comprises a vacuum chamber with an outer wall enclosing a volume that can be evacuated. The vacuum system further comprises a detection device with a detection element for detecting waves and / or particles. The detection device is arranged outside the vacuum chamber.

[0013] The detection device is much simpler and accessible from the outside. Therefore, the vacuum can be maintained, and the vacuum chamber does not need to be opened or entered to access the detection device. This reduces the technical complexity. Furthermore, the volume of the vacuum chamber can be reduced, thus reducing the material requirements for the vacuum system. Furthermore, the detection device can be manufactured, at least in large parts, with a significantly reduced wall thickness, since the outer walls, at least for the most part, do not have to withstand the vacuum, but only the pressure prevailing outside the vacuum chamber. This reduces the technical complexity and costs.

[0014] The vacuum chamber is defined by the outer wall and is suitable for generating a vacuum. In particular, the outer wall has at least one evacuation opening for connecting a vacuum source. In this way, a vacuum can be generated in the vacuum chamber, thus evacuating the volume. The evacuation opening is open towards the volume. The evacuation opening runs through the outer wall. The evacuation opening can be connected to a vacuum source, for example a vacuum pump. In this way, the volume can be evacuated. The outer wall can be curved and / or have ribs to increase rigidity. The vacuum system can comprise the vacuum source. The vacuum chamber or its outer wall can be made of stainless steel or aluminum. The vacuum chamber can have a coating or lining, for example of cadmium. The volume can be used for irradiation by means of particles and / or waves.The volume can be used to accommodate a sample. In this case, a sample environment can be present within the volume, in or on which a sample can be positioned. Alternatively, the sample environment can be present in another component located adjacent to the volume.

[0015] The detection device is a device for detecting waves and / or particles. It contains a detection element that interacts with the waves and / or particles, thus making them detectable. The waves and / or particles are typically emitted or deflected by a sample located in a sample environment. This allows information about the sample and / or the waves or particles to be obtained. The detection element contains a material that interacts with the waves and / or particles or is configured to receive such a material. A detection device can have a plurality of detection elements. The detection device can be configured as a so-called multi-grid detector. In this case, it comprises a plurality of inserted sheets and / or taut wires. A detection element can be configured as a scintillator.

[0016] In one embodiment, the detection device has one or more cables for transmitting data to an evaluation unit. Because the detection device is located outside the vacuum chamber, the cables do not need to run through the vacuum. This reduces the technical complexity.

[0017] The vacuum system can interact with a radiation source that can bombard a sample held in the sample environment with radiation, causing the sample to emit particles and / or waves. For example, the radiation source can generate a beam of neutrons, electrons, or protons. The radiation source is typically located outside the vacuum chamber and / or outside any sample receiving module, in particular at a distance of more than 100 m. The vacuum system can include the radiation source.

[0018] In one embodiment, the detection device comprises a gas container for containing a gas or gas mixture. A gas container is a container for containing a gas or gas mixture. This can mean permanent containment, in which the gas or gas mixture remains essentially unchanged in terms of mass, pressure, and composition over periods of hours to months. Alternatively, it can mean temporary or short-term containment. In particular, the gas container is essentially hermetic. The gas container is arranged outside the vacuum chamber.

[0019] Within the detection element—in this embodiment, within the gas or gas mixture—interactions can occur between particles and / or waves to be detected and gas particles of the detection element. A wire and / or sheet can be present within the detection element. The collisions can release particles whose electrical charge can be dissipated through the wire and / or sheet and thus localized. The interactions are thus detected by the detection device.

[0020] The gas or gas mixture serves to interact with the waves and / or particles. According to the invention, the detection element can be the gas container, into which a gas can be introduced to detect the waves and / or particles. The gas or gas mixture itself does not necessarily have to be arranged in the gas container to obtain a vacuum system according to the invention.

[0021] This achieves a number of advantages. Firstly, the volume of the vacuum chamber can be significantly reduced, as gas containers are typically very large and are no longer present within the vacuum chamber. The achievable volume reduction can be in the range of 50%, allowing significantly lower material expenditure for the vacuum system than with conventional designs. Furthermore, the tightness of the system is improved. No or significantly less gas can escape from the gas container into the vacuum chamber. With the conventional arrangement of the gas container in the vacuum chamber, gas always escapes from the gas container into the remaining volume of the vacuum chamber, as 100% tightness is technically not achievable. This disrupts the vacuum, causes gas losses, and increases the effort required for evacuation. In contrast, the solution according to the invention significantly reduces the leakage rate, thus improving the quality of the vacuum and reducing the pumping effort.In one embodiment, the detection device is configured to detect neutrons. In this embodiment, the volume serves to transmit neutrons. To ensure an undisturbed trajectory of the neutrons, collisions with gas particles must be prevented. The neutrons should therefore move undisturbed so that they can subsequently be detected by a detection device. This is achieved by the evacuated volume. The detection device comprises the gas container. In particular, the detection is based on the detection of interactions between the neutrons and gas particles in the gas container. For example, such interactions can trigger electrical signals that can be detected in a suitable manner. For example, collisions between electrically neutral neutrons and particles of the gas or gas mixture trigger charged particles, whose electrical charge can then be detected.For example, the electrical charges can be conducted via wires. The position of the collision can be determined via the path of the current. In particular, each wire is read individually to achieve high spatial resolution in the detection device. More than 1,000 wires and / or sheets can be present, thus providing more than 1,000 measurement channels, to enable high-resolution detection. The vacuum system can be provided as part of a neutron scattering system and / or for neutron spectroscopy. Alternatively, the detection device can be designed to detect electrons or protons.

[0022] In one embodiment, the detection device comprises a processing unit for processing detected signals. The processing unit is arranged outside the vacuum chamber. For example, the processing unit can be configured to process, for example, amplify and / or transmit electrical signals. The signals can be caused by interactions between neutrons and gas particles in the gas container. The processing unit can contain electronic components. The processing unit is arranged outside the vacuum chamber and therefore does not need to be encapsulated.

[0023] In particular, the detection device further contains an interface for transmitting the signals to an evaluation unit. This is, in particular, a wired transmission. However, wireless transmission is also possible in principle. In one embodiment, the processing unit can be cooled by means of a cooling medium. The cooling medium can be gaseous or liquid. It can be a cooling gas or cooling gas mixture, such as cooling air. It can be a cooling liquid, such as cooling water. In particular, the processing unit contains at least one channel and typically several channels through which the cooling medium can flow. In this way, the processing unit can be cooled by means of the cooling medium. The processing unit can comprise a fan for implementing a cooling gas flow.

[0024] The detection device can comprise one or more lines for supplying and / or removing the cooling medium. In conventional systems, the line or lines for supplying and / or removing the cooling medium run through the vacuum chamber, which is not necessary with the invention. This eliminates any impairment of the vacuum, and any necessary maintenance is significantly simplified due to the improved accessibility. The technical complexity of the lines is also reduced.

[0025] In one embodiment, the gas container is directly adjacent to the vacuum chamber.

[0026] In one embodiment, the vacuum chamber has at least one opening in the outer wall and the detection device is adjacent to the opening in such a way that at least a section of a wall of the detection device limits the volume of the vacuum chamber.

[0027] The detection device comprises a wall. In particular, this refers to an outer wall that delimits the detection device to the outside. Typically, this refers to the wall on one side that delimits the detection device to this side. The opening of the vacuum chamber is typically a through-opening. The detection device is typically arranged such that a region of the wall of the detection device closes the opening. In particular, one side of the detection device closes the opening. In this case, outer regions of the wall, in particular, rest against the outer wall of the vacuum chamber surrounding the opening. In one embodiment, the detection device is designed and arranged such that only one wall exists between the volume to be evacuated and the gas or gas mixture. This reduces the attenuation of waves or particles to be detected, such as neutrons, and leads to better detection.There may be several gas containers in the area of ​​the opening.

[0028] The area of ​​the wall of the detection device that closes the opening is, in particular, an outer wall of the gas container. In this embodiment, the wall of the detection device can serve simultaneously as the outer wall of the gas container and the outer wall of the vacuum chamber. Only this one side of the gas container needs to be vacuum-tight and withstand the vacuum. The remaining five sides, for example, only need to withstand the external pressure. The wall of the detection device can be made partially or entirely of aluminum.

[0029] In particular, a seal is arranged between the edge of the outer wall of the vacuum chamber that defines the opening and the detection device. A seal can be arranged on the detection device and / or on the outer wall of the vacuum chamber. In this way, the penetration of air into the vacuum chamber in the evacuated state can be prevented.

[0030] In one embodiment, the detection device is designed and arranged such that it supports the outer wall on an upper side of the vacuum chamber against a downward force caused by the vacuum. In other words, the detection device is designed as a load-bearing wall of the vacuum chamber. It supports the upper side, which is pulled downwards by the vacuum. It thus serves to provide mechanical stability or rigidity to the vacuum chamber. Alternatively or additionally, the detection device can also be designed and arranged such that it supports the outer wall on an underside of the vacuum chamber against an upward force caused by the vacuum and / or that it supports the outer wall on a radially outward-facing shell side of the vacuum chamber against an inward force caused by the vacuum.

[0031] In one embodiment, the detection device is mechanically detachably attached to the outer wall of the vacuum chamber. The detection device can thus be removed, for example, to replace the detection device. In particular, this refers to non-destructive, reversible detachment. The detachable mechanical attachment can comprise screws, for example. Alternatively or additionally, a holding system, for example, comprising one or more retaining brackets, can be arranged. The holding system can hold the detection device to the opening of the vacuum chamber.

[0032] In one embodiment, the detection device is constructed in two parts and comprises a wall element and an outer element. The wall element of the detection device is attached to the outer wall or can be attached thereto. The outer element of the detection device is mechanically releasably attached to the wall element or can be mechanically releasably attached thereto. The wall element is located radially inward and the outer element is located radially outward. The wall element closes the vacuum chamber. The outer element can contain the gas container. In this way, the gas container and / or one or more detection elements can be removed, for example for maintenance. This embodiment is particularly advantageous in the case of multiple detection devices, since a vacuum can be generated even if not all detection devices are present.

[0033] In one embodiment, the vacuum system comprises a plurality of detection devices. The detection devices are arranged, in particular, on a spherical surface, typically on a circular arc, and preferably in a semicircle. Thus, all detection devices are at the same distance from the sample. The detection devices can be of similar design.

[0034] In other words, several detection devices are arranged outside the volume. This allows, for example, neutrons emitted by a sample at different angles to be detected. With detection devices arranged in a semicircle, for example, a measurement angle of 180° can be covered.

[0035] In one embodiment, the vacuum chamber is substantially semicircular. The vacuum chamber has an approximately semicircular basic shape. Minor deviations from the semicircle shape are included. In one embodiment, the vacuum chamber has a maximum extension of between 3 m and 20 m. In particular, the maximum extension is between 4 m and 10 m. The maximum extension is measured in plan view along the longest straight line running through the vacuum chamber. In the case of a semicircular vacuum chamber, this can be the diameter of the semicircle. In particular, the maximum extension is between 5 m and 7 m. The radius can be, for example, 3 m. The height can be, for example, 2.5 m.

[0036] In one embodiment, the vacuum chamber has a maximum length between 1 m and 20 m. Typically, the trajectory, for example for neutrons, then has a length corresponding to half this value, i.e., between 0.5 m and 10 m.

[0037] In one embodiment, the vacuum chamber does not contain any access through which at least one person could enter the volume. Although the vacuum chamber is typically large enough for one or more people to enter the volume, for example due to the necessary flight distances, this is no longer necessary due to the externally arranged detection devices, so that a door or the like can be omitted. This significantly reduces the design effort. Nevertheless, it cannot be ruled out that a person could enter the volume if a detection device is removed. This could be the case, for example, if the vacuum chamber was initially lined with cadmium.

[0038] In one embodiment, the vacuum system further comprises a sample receiving module separate from the vacuum chamber. The sample receiving module has a sample environment for receiving a sample. The sample receiving module is mechanically attached to the vacuum chamber.

[0039] In other words, the sample that emits waves or particles is arranged in a separate module and not, as in conventional systems, in the vacuum chamber itself. Separate means that the sample holder module is not made integrally with the vacuum chamber. In this design, the sample holder module is located outside the vacuum chamber. In particular, the sample holder module is mechanically detachably attached to the vacuum chamber. It can be attached to the vacuum chamber, for example, by attaching it to the outer wall of the vacuum chamber. This design enables a modular structure in which the sample holder module can be mechanically detachable and, for example, replaced. In this way, different sample holder modules can be used for different investigations. The sample holder module can therefore easily be made from a different material than the actual vacuum chamber.For example, the sample receiving module can be made of aluminum, which cannot be magnetized. The vacuum chamber can be made of cheaper and more easily processed stainless steel. The modularity also allows for adaptation to future requirements without having to replace the entire chamber.

[0040] In particular, the sample receiving module is arranged such that waves or particles emitted by a sample arranged in the sample environment can pass from the sample receiving module into the vacuum chamber in order to pass from the vacuum chamber further to the detection device.

[0041] In particular, the sample receiving module contains an outer wall. A seal is typically arranged between the outer wall of the sample receiving module and the outer wall of the vacuum chamber. This can prevent air from entering the vacuum chamber when evacuated. For example, this seal can be an inflatable seal.

[0042] In particular, the outer wall of the sample receiving module and / or the outer wall of the vacuum chamber contains an opening, wherein the opening is arranged in such a way that waves or particles emitted by the sample move through the opening toward the detection device. In the case of an opening in the outer wall of the vacuum chamber, the sample receiving module can serve to define the vacuum chamber, similar to the detection device. In the case of two overlapping openings in the outer wall of the sample receiving module and the outer wall of the vacuum chamber, the sample receiving module becomes part of the space to be evacuated. In this case, the emitted particles or waves can freely pass from the sample receiving module into the vacuum chamber.

[0043] The sample receiving module typically contains a sample environment in which a sample can be placed that is intended to emit waves or particles. The sample environment in particular contains a sample holder in or on which the sample is positioned. The sample environment is typically configured to condition the sample. For example, it can provide a desired temperature and / or a desired magnetic field to which the sample is exposed when it is positioned in the sample holder. For example, the sample environment can be cryogenic or strongly magnetic. Accordingly, the sample receiving module can comprise a cryostat or a strong magnet. The sample holder can be arranged interchangeably in the sample environment.

[0044] In one embodiment, the gas container is closed to contain the gas or gas mixture. In other words, the gas or gas mixture is permanently arranged in the gas container. This is not precluded by the possibility of a closable opening through which the gas or gas mixture can be introduced into or discharged from the gas container. In particular, helium-3 can be used as the gas or gas mixture in this embodiment. Here, the detection device is designed as a helium-3 detector. In this case, it typically comprises a plurality of gas containers.

[0045] In one embodiment, the gas container is open to accommodate the gas or gas mixture. In particular, the gas container is connected to a supply line and / or a discharge line for supplying and / or discharging the gas or gas mixture.

[0046] In this embodiment, the gas container serves to temporarily hold the gas or gas mixture. In one embodiment, the gas or gas mixture can simply flow through the gas container without a significant residence time in the gas container. In particular, continuous purging takes place.

[0047] The supply line serves to introduce the gas or gas mixture into the gas container. The discharge line serves to discharge the gas or gas mixture from the gas container. In particular, the vacuum system further comprises a gas flow unit that generates a gas flow through the supply line, the gas container, and the discharge line. In particular, a mixture of argon and carbon dioxide can be used as the gas or gas mixture in this embodiment. The detection device can have one or more gas containers. If there are multiple gas containers, these can be connected to one another or be present individually. Multiple gas containers can be directly adjacent to one another or spaced apart from one another. One or more gas containers of the detection device can be filled or can be filled with gas or gas mixture that has substantially or exactly atmospheric pressure. This is independent of the open or closed design of the gas container.

[0048] A further aspect of the invention is a detection device for a vacuum system. In particular, the detection device is a detection device for a vacuum system according to one of the preceding claims. The detection device comprises a detection element for detecting waves and / or particles. The detection element is in particular a gas container for accommodating a gas or gas mixture. The detection device has, at least on one side of the detection device, a wall which is not designed to be arranged in a vacuum. In other words, the wall is dimensioned such that it cannot withstand a vacuum. In particular, the wall is not designed to be arranged in a vacuum located outside the detection device. The use of the detection device in a vacuum is therefore not intended and / or not possible.In this context, vacuum means a vacuum that is necessary for the scheduled operation of the vacuum system.

[0049] The side wall is typically dimensioned to withstand atmospheric pressure, but not a vacuum. This is especially true given the gas pressure inside the gas container under the operating conditions of the detection device.

[0050] All features, advantages and effects of the vacuum system and its parts described above, in particular the detection device, apply accordingly to this aspect of the invention and vice versa.

[0051] The wall is, in particular, a wall that delimits the gas container. It is arranged, in particular, on a first side of the detection device and delimits the detection device on this side. In particular, the wall is not vacuum-tight on several, preferably five, sides of the detection device.

[0052] The wall can be dimensioned on another side to withstand a vacuum. This side can close an opening in the outer wall of the vacuum chamber. The remaining five sides, for example, only need to withstand the pressure prevailing outside the vacuum chamber. This pressure is typically approximately atmospheric pressure.

[0053] Below, exemplary embodiments of the invention are explained in more detail with reference to the figures. Features of the exemplary embodiments can be combined individually or in multiples with the claimed subject matter, unless otherwise stated. The claimed scope of protection is not limited to the exemplary embodiments.

[0054] They show:

[0055] Figure 1 : a schematic representation of a conventional vacuum system,

[0056] Figure 2: a schematic representation of a vacuum system according to the invention,

[0057] Figure 3: a perspective view of a conventional vacuum system from above, as well as

[0058] Figure 4: a perspective view of a vacuum system according to the invention.

[0059] Figures 1 and 3 have already been discussed in the course of the assessment of the state of the art.

[0060] Figure 2 schematically shows a vacuum system 1 according to the present invention. The vacuum system 1 comprises a vacuum chamber 10, which is defined by an outer wall 12. A detection device 20 is located outside the vacuum chamber 10. The detection device 20 is directly adjacent to the vacuum chamber 10.

[0061] Not shown, but usually nonetheless present in the vacuum chamber 10, is a sample environment in which a sample can be positioned to emit waves and / or particles. For example, the sample can be bombarded with neutrons using a radiation source for this purpose. The waves or particles emitted in this way, for example neutrons, pass through the vacuum chamber 10 into the interior of the gas container 22 of the detection device. The detection element, not provided with a separate reference numeral, is the gas container 22 in the figures shown here. The gas or gas mixture located in the gas container 22 interacts with the emitted waves or particles to detect them. The vertical lines indicate wires and / or sheets located in the gas container and used to derive electrical signals from electrically charged particles triggered by collisions. In this way, the neutrons can be detected.

[0062] The vacuum chamber 10 has a continuous opening 17 in the area of ​​the detection device. The outer wall of the detection device 20 is designed on the side 25 shown on the left so that it can mechanically withstand the vacuum. The outer wall of the detection device 20 on the side 25 can simultaneously be the wall delimiting the gas container 22 or can encompass it. The outer wall 12 of the detection device 20 is not designed on the remaining sides 24 so that it can withstand a vacuum. It is correspondingly smaller in terms of its rigidity and material usage. This is possible because only the side 25 shown on the left comes into contact with the vacuum inside the vacuum chamber 10.

[0063] A cable bundle 27 extends from the detection device 22. The cable bundle can be used to conduct signals from the detection device 20 to an evaluation device. The cable bundle can be used to conduct signals from a control unit to the detection device 20. The cable bundle can be used to conduct a cooling medium to and from the detection device 20. In the area of ​​the detection device 20, the cable bundle 27 leads in particular to a processing unit of the detection device 20, which serves to process and forward detected signals.

[0064] According to the invention, it is not necessary for the cable assembly 27 to extend through the vacuum chamber 10 or to traverse the outer wall 12 of the vacuum chamber 10. In this way, the design effort for the cable assembly 27 can be significantly reduced.

[0065] Figure 4 shows a perspective view of an inventive

[0066] Vacuum system 1 with a vacuum chamber 10 containing a volume 15 to be evacuated, defined by an outer wall 12. The vacuum chamber 10 is approximately semicircular in shape. The volume 15 has a maximum extension of 6 m. The maximum extension corresponds to the diameter of the semicircle. In comparison, the conventional vacuum system shown in Figure 3 requires a maximum extension of the volume of 9 m, with the distances between the sample environment 30 and the detection devices 20 of both vacuum systems being the same. This clearly shows that the inventive design enables a significant reduction in material usage.

[0067] The vacuum chamber 10 contains several openings 17 in its outer wall 12. In the embodiment shown here, the openings 17 are designed as through-openings. There are ten through-openings, which are arranged, for example, evenly distributed over the semicircular arc.

[0068] Detection devices 20 are arranged outside the vacuum chamber 10 and directly adjacent to the outer wall 12 of the vacuum chamber 10. Each detection device 20 covers an opening 17 in the outer wall 12. In this way, a section of the wall of the detection device 20 defines the volume 15 of the vacuum chamber 10. In the exemplary embodiment of the vacuum system 1 shown here, ten detection devices 20 are provided, of which only eight are shown. In the lower part of the image, two detection devices 20 have been omitted for clarity, so that the corresponding openings 17 in the vacuum chamber 10 are visible. These can be used as access to the vacuum chamber 10.

[0069] To evacuate volume 15, all openings 17 must be closed. Each opening 17 can be closed with a detection device 20. In the embodiment shown in Figure 4, the detection devices are constructed in two parts and include an inner wall element and an outer element. The outer element can be mechanically detached from the wall element. Thus, one or more openings 17 can each be closed with a wall element without the outer element having to be present at the same time. The processing unit 26 is arranged on the outer element.

[0070] The detection devices 20 and, in particular, the wall elements are designed as load-bearing elements. They support the outer wall 12 on the top side 13 of the vacuum chamber 10. The vacuum generates a downward force in the top side 13, which is at least partially absorbed by the detection devices 20 and the wall elements. In this way, the webs of the outer wall 12 located between the openings 17 can be made smaller. In the same way, the detection devices 20 support the underside downward and the radial outer walls inward. In this way, they stiffen the entire structure of the vacuum chamber.

[0071] A detection device 20 is typically attached to the outer wall 12 with screws. Additionally, one or more retaining brackets 38 may be provided to hold the detection device 20 in position and / or press it against the outer wall 12. This is particularly advantageous when the vacuum chamber 10 is not evacuated. Once the vacuum chamber 10 is evacuated, the detection devices 20 and / or wall elements are pressed against the outer wall 12 by the atmospheric pressure prevailing outside the vacuum chamber 10, thereby holding them in position.

[0072] Each of the detection devices 20 contains a gas container 22 and a processing unit 26. The functional principle of the detection devices 20 has already been described above. Each detection device 20 further contains a processing unit 26, in which detected signals are processed and / or transmitted to an evaluation unit. Cables for transmitting the data can be connected to the processing unit 26 shown. These cables do not need to run through the vacuum, since the processing units 26 are easily accessible from the outside.

[0073] In particular, the processing unit 26 can be cooled using a cooling medium. Due to the external arrangement of the processing unit 26, air cooling can be implemented particularly easily by creating a cooling air flow through the processing unit 26. For this purpose, a fan of the processing unit 26 can be provided, for example. Cooling with a liquid cooling medium is also possible. For this purpose, the processing unit can have corresponding channels to which suitable lines for the cooling medium can be connected. In the vacuum system 1 shown here, the sample environment is arranged centrally in a sample receiving module 32, which is separate from the vacuum chamber 10. This module is located in the center of the semicircle and is, in particular, mechanically detachably connected to the vacuum chamber 10. The sample receiving module 32 has a circular-cylindrical basic shape and contains an opening 36 in its outer surface.The opening 36 extends over approximately 180° and overlaps with the semicircular vacuum chamber 10. In this way, emitted waves and / or particles can be detected at an angle of approximately 180°.

[0074] In one embodiment, the semicircular vacuum system 1 of Figure 4 replaces the vacuum system 1 of Figure 3. Accordingly, the beam conditioning device 40 and / or the beam catcher 42 can also be present in the vacuum system 1 according to the invention. Of course, the door 34 is not necessary in the vacuum system 1 according to the invention even in such a configuration.

[0075] List of reference symbols

[0076] Vacuum system 1

[0077] Vacuum chamber 10

[0078] Exterior wall 12

[0079] Top 13

[0080] Volume 15

[0081] Opening 17

[0082] Detection device 20

[0083] Gas tank 22

[0084] Page 24

[0085] Page 25

[0086] Processing unit 26

[0087] Line package 27

[0088] Sample environment 30

[0089] Sample intake module 32

[0090] Door 34

[0091] Opening 36

[0092] Holding bracket 38 Beam conditioning device 40

[0093] Beam catcher 42

Claims

Claims 1. Vacuum system (1) comprising a vacuum chamber (10) with an outer wall (12) enclosing a volume (15) which can be evacuated, wherein the vacuum system (1) further comprises a detection device (20) with a detection element for detecting waves and / or particles, characterized in that the detection device (20) is arranged outside the vacuum chamber (10).

2. Vacuum system according to claim 1, characterized in that the detection device (20) comprises a gas container (22) for receiving a gas or gas mixture.

3. Vacuum system (1) according to one of the preceding claims, characterized in that the detection device (20) is configured for the detection of neutrons.

4. Vacuum system (1) according to one of the preceding claims, characterized in that the detection device (20) has a processing unit (26) for processing detected signals, wherein the processing unit (26) is arranged outside the vacuum chamber (10).

5. Vacuum system (1) according to the preceding claim, characterized in that the processing unit (26) can be cooled by means of a cooling medium.

6. Vacuum system (1) according to one of the preceding claims, characterized in that the vacuum chamber (10) has an opening (17) in the outer wall (12) and the detection device (20) adjoins the opening (17) in such a way that at least a section of a wall of the detection device (20) limits the volume (15) of the vacuum chamber (10).

7. Vacuum system (1) according to the preceding claim, characterized in that the detection device (20) is designed and arranged such that it supports the outer wall (12) on a top surface (13) of the vacuum chamber (10) against a downward force caused by the vacuum.

8. Vacuum system (1) according to one of the two preceding claims, characterized in that the detection device (20) is mechanically detachable and attached to the outer wall (12) of the vacuum chamber (10).

9. Vacuum system (1) according to one of the preceding claims, characterized in that the detection device (20) is constructed in two parts, wherein a wall element of the detection device (20) is attached or can be attached to the outer wall (12) and an outer element of the detection device (20) is or can be mechanically detachably attached to the wall element.

10. Vacuum system (1) according to one of the preceding claims, characterized in that the vacuum system (1) comprises a plurality of detection devices (20), wherein the detection devices (20) are in particular arranged on a circular arc.

11. Vacuum system (1) according to one of the preceding claims, characterized in that the vacuum chamber (10) is essentially semicircular.

12. Vacuum system (1) according to one of the preceding claims, characterized in that the vacuum chamber (10) has a maximum extent between 3 m and 20 m, in particular between 4 m and 10 m.

13. Vacuum system (1) according to one of the preceding claims, characterized in that the vacuum system (1) further comprises a sample receiving module (32) separate from the vacuum chamber (10) with a sample environment (30) for receiving a sample, wherein the sample receiving module (32) is mechanically attached to the vacuum chamber (10).

14. Vacuum system (1) according to one of claims 2 to 12, characterized in that the gas container (22) is closed for receiving the gas or gas mixture.

15. Vacuum system (1) according to any one of claims 2 to 12, characterized in that the gas container (22) is open for receiving the gas or gas mixture and is connected to an inlet and / or outlet.

16. Detection device (20) for a vacuum system (1) according to any one of the preceding claims, wherein the detection device (20) comprises a detection element for detecting waves and / or particles, wherein the detection device (20) is located at least on one side (24) of the Detection device (20) has a wall which is not designed to be arranged in a vacuum.

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