Spacer element, handover assembly, and spectroscopic analysis device

Abstract

The utility model discloses a spacing element, a connecting assembly and a spectral analysis device. The spacer element is used for a plasma interface assembly in a spectral analysis device, for example in a mass spectrometry device. Specifically, the spacer element is for an interface assembly comprising an orifice element defining an orifice for passing plasma from a plasma source and a cooling element for cooling the orifice element. The spacer element includes an electrically isolated body configured to be interposed between the aperture element and the cooling element. The electrical isolation body is provided with an opening. A conductive layer is disposed on the electrically isolated body to face the aperture element.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a spacer element, an interface assembly and a spectroscopic analysis device. BACKGROUND

[0002] A spectroscopic analysis device, such as an inductively coupled plasma mass spectrometer (ICP-MS), can include a hot plasma stream that vaporises and ionises a sample so that ions from the sample can then be processed or introduced to a spectrometer for measurement or analysis. Extraction and transfer of ions from the plasma involves directing a portion of the ions formed by the plasma through an interface assembly, which facilitates bridging the pressure difference between the plasma source and the spectrometer. The interface assembly can include a first orifice disposed in a skimmer and a generally narrower second orifice disposed in a separator (often referred to as a skimmer cone and a separator cone, respectively).

[0003] In conventional spectroscopic analysis devices, the skimmer and the separator are typically grounded. However, spectroscopic analysis devices can also be operated such that one or both of the skimmer and the separator are not grounded. Furthermore, spectroscopic analysis devices are typically required to operate with a vacuum and the plasma stream must be maintained at extremely high temperatures of up to 10,000K. Therefore, components within the spectroscopic analysis device, particularly components in the interface assembly, must be conditioned and must withstand the harsh conditions imposed by the hot plasma without interfering with ion transfer or negatively affecting measurement and analysis.

[0004] Accordingly, a large number of different technical (e.g. electrical, thermal and material) requirements within the spectroscopic analysis device must be satisfied, which can result in design requirements conflicting with one another. SUMMARY

[0005] The inventors have recognised that the above-discussed conflicting design requirements can be addressed by providing a spacer element in the interface assembly to electrically isolate the orifice element from the remainder of the interface assembly, whilst also making an electrical connection to the orifice element. This is achieved by providing a spacer element as detailed below between the orifice element of the interface assembly and a cooling element, such as a cooling plate, to facilitate an isolated electrical connection to the orifice element, whilst maintaining sufficient heat transfer from the orifice element to the cooling element.

[0006] In a first embodiment, a spacer element for a plasma interface assembly in a spectroscopic analysis device is provided. The plasma interface comprises an orifice element defining an orifice for passage of plasma (or charged ions in the plasma) from a plasma source, and a cooling element for cooling the orifice element. In use, the plasma flows through the plasma interface into a spectrometer, such as for a mass spectrometer. In particular, the device can be a mass spectrometry or optical spectroscopy analysis device, for example.

[0007] The spacer element comprises an electrically isolating body configured to be inserted between the orifice element and the cooling element. In this way, the spacer element electrically isolates the orifice element to prevent unwanted movement of electrical charges across components in the device, which can cause changes in electric fields or disturb the charged ions in the interface, leading to calibration or measurement disturbances, component damage or safety risks. The electrically isolating body is provided with an opening that facilitates positioning of the body between and around the orifice element and the cooling element. Within reasonable manufacturing tolerances, the electrically isolating body can be planar such that it conforms to the orifice element and / or the cooling element. Advantageously, this enables a secure fit between the components of the interface assembly to minimise the spacing between the components of the interface assembly. The opening of the electrically isolating body can be any space or gap in the body through which ions generated by the plasma source can flow.

[0008] The spacer element also comprises an electrically conductive layer provided on the electrically isolating body to face the orifice element. In this way, the electrically conductive layer can be electrically coupled with the orifice element when the electrically isolating body is inserted between the orifice element and the cooling element. The layered configuration of the spacer element enables electrical conduction with the orifice element without any electrical contact with the cooling element in order to be in electrical communication with the orifice element, while preventing electrical interference with other components of the spectroscopic analysis assembly. In this way, a voltage can be applied to the orifice element to create a field with a selected bias voltage in a portion of the interface assembly. For example, the intensity of the ion flow from the plasma source can be increased by passing the ions through a field that is biased in a desired direction.

[0009] The spacer element can comprise a contact tab extending from the electrically conductive layer and configured to act as an electrical contact to facilitate electrical connection with the electrically conductive layer. The contact tab can be provided on a corresponding extension of the electrically isolating body. In some examples, the contact tab extends generally in the plane of the spacer element and substantially radially outwardly from the electrically conductive layer, such as at a right angle, or can extend at any angle in a plane away from the electrically conductive layer, such as in a direction away from or through the electrically isolating body.

[0010] The shape of the electrically isolating body can be substantially ring-like or annular to accommodate the common form factor of orifice elements and allow plasma and / or ions to pass through the opening when the spacer element is placed between and around the orifice element and the cooling element. For example, the shape of the electrically isolating body can be any of a closed loop, a C-shape, an oval, or a square. In some examples, the shape of the electrically isolating body conforms to the shape of the cooling element, orifice element, or other component of the interface assembly.

[0011] The thickness of the electrically isolating body can be 90 pm to 110 pm, or can be thicker than 110 pm, for example 150 pm, or thinner than 90 pm, for example 50 pm. It will be appreciated that minimizing the thickness of the electrically isolating body increases the thermal conductivity and maximizes the cooling of the orifice element with the cooling element. A balance can be reached for the desired thermal regulation. For example, the thickness of the electrically isolating body can be smaller in embodiments that use materials with limited inherent thermal conductivity, or can be larger in embodiments that use materials with higher thermal conductivity. One example of an electrically isolating body with sufficient thermal transfer properties is a layer or sheet of polyimide, for example Kapton®.

[0012] The electrically conductive layer can comprise any conductive material known in the art, such as copper. For example, the layer can comprise a copper foil and / or can comprise a copper track disposed on the surface of the electrically isolating layer. The total thickness of the spacer can be less than 1 mm. For example, the thickness of the electrically conductive layer can be 30 pm to 40 pm.

[0013] In some examples, the spacer element further comprises a layer of gold disposed on the electrically conductive layer. Advantageously, by disposing a layer of gold on the electrically conductive layer, for example on a copper track, this renders the electrically conductive layer inert and enables the spacer to be used directly in the vicinity of a plasma in a vacuum. In some examples, the thickness of the layer of gold is 2 pm to 5 pm. However, it will be appreciated that a layer of gold thicker than 5 pm can also be used. The layer of gold is electrically conductive, so the electrical conduction between the electrically conductive layer and the orifice element is maintained.

[0014] As described herein, the spacer element serves to electrically isolate the orifice element of the interface assembly from other components, while enabling electrical connections to be made to the orifice element. Furthermore, the material geometry of the spacer ring can facilitate thermal conductivity and enable the orifice element to be sufficiently cooled with a cooling element. In this way, the spacer ring advantageously combines the contradictory properties of electrical insulation and thermal conductivity. For example, the overall thickness of the spacer ring can be 135 pm, plus or minus 15 pm. In other examples, the thickness of the spacer element can be greater than 135 pm (e.g. 1 mm, evidenced by a greater conductive copper thickness and / or a greater electrical isolation body thickness), while still maintaining sufficient thermal conductivity. Crucially, the material and corresponding geometry of the spacer element is arranged to maintain the operating temperature of the orifice element and surrounding components by cooling the components with a cooling element. For example, the thermal conductivity of the spacer element can be 0.1 Watts per meter Kelvin to 0.5 Watts per meter Kelvin. It will be appreciated that higher or lower thermal conductivities are also possible, depending on the specific material usage or design of the interface assembly.

[0015] In some examples, the spacer element further comprises a through-hole to accommodate a fixing in the interface assembly. The through-hole can be positioned around the perimeter of the spacer element. The fixing secures the orifice element to the cooling element, and the spacer element therebetween, and can comprise any suitable fixing known in the art, such as a bolt, screw or rivet.

[0016] In another embodiment, an interface assembly for a spectrometer comprises an orifice element arranged on a cooling element, such as a cooling plate. The cooling element can be a gas or liquid cooled by coolant channels in the cooling plate, for example with water at a temperature of 15°C to 25°C. A spacer element as described above is positioned between the orifice element and the cooling element. Furthermore, the interface assembly comprises electrical leads for supplying a voltage to the orifice element, which are connected to the spacer element. The spacer element can be removably secured between the orifice element and the cooling element, which advantageously enables the spacer element to be easily replaced.

[0017] In some examples, the orifice element can comprise one or a combination of a skimmer and a sampler. The skimmer and sampler can be a skimmer cone and a sampler cone, respectively, or they can be formed of other suitable shapes known to the skilled person.

[0018] In some examples, the orifice element can comprise multiple component parts, such as a skimmer and a skimmer holder. Alternatively, the orifice element can be a single workpiece and / or the orifice element holder can be part of another structure of the spectrometric device. In both such examples, the spacer element is positioned in a location between the orifice element and the cooling element in order to electrically isolate the orifice element, while enabling electrical connections to be made to the orifice element.

[0019] In another embodiment, a spectrometry device comprises an interface assembly and a spacer element as described above. The spectrometry device can be a mass spectrometer or an optical spectrometer. For example, the device can be an inductively coupled plasma mass spectrometer (ICP-MS), or alternatively, the device can be an inductively coupled plasma optical spectrometry system, for example for inductively coupled plasma optical emission spectrometry (ICP-OES). BRIEF DESCRIPTION OF DRAWINGS

[0020] Embodiments of the present disclosure will now be described by way of example with reference to the accompanying drawings, in which:

[0021] Figure 1 a top view of an interface assembly for a spectrometry device is illustrated;

[0022] Figure 2 a cross-sectional view of the interface assembly of Figure 1 along the section line indicated in Figure 1 is illustrated;

[0023] Figure 3 a side elevational view of the interface assembly of Figure 1 is illustrated;

[0024] Figure 4 an exploded view of the interface assembly of Figure 1 is illustrated;

[0025] Figure 5a and Figure 5b a top view and a bottom view of a spacer element for a plasma interface assembly are respectively illustrated; and

[0026] Figure 6 a cross-sectional view of the spacer element of Figure 5a is illustrated. DETAILED DESCRIPTION

[0027] For the sake of clarity, the following will describe embodiments with reference to an inductively coupled plasma mass spectrometry (ICP-MS) device. However, it will be appreciated that the present disclosure is conveniently applicable to a plasma interface assembly of any known spectrometry device, for example for optical emission spectrometry or mass spectrometry.

[0028] The environment at the interface within an ICP-MS device can be particularly harsh, with high temperatures, large pressure differentials, presence of a stream of charged plasma, geometric constraints, and thermal / electrical conduction standards. The spacer element 200 combines these requirements with one component having a variety of technical properties, such as: functionality in close proximity to a charged plasma; functionality at high temperatures; functionality in a vacuum; inert or non-reactive so as not to affect the sample; electrical isolation; thermal conduction; consistent and minimal spacing between the components of the interface assembly; ease of replacement; and economic manufacturability.

[0029] Figures 1 to 4 Various views of an interface assembly 100 for directing ions from a plasma source to a spectrometer are illustrated. In particular, Figure 2 Various views of an interface assembly 100 for directing ions from a plasma source to a spectrometer are illustrated. In particular, Figure 1 A cross-section is illustrated as Figure 3 A side elevation view is depicted, and Figure 4 An exploded view is depicted to illustrate the various components of the interface assembly.

[0030] The interface assembly 100 includes a sampler cone 102, a skimmer cone 104, a skimmer cone holder 106, a spacer element 200, and a cooling plate 108. While the detailed description refers to the cooling plate 108, it should be understood that this is an example of a more general cooling element. The sampler cone 102 and the skimmer cone 104 together facilitate the transfer of ions from a plasma source (which is typically at atmospheric pressure) to an analysis region of a mass spectrometer, which is a vacuum or very low pressure. In operation, high temperature ions travel through an orifice 112a of the sampler cone 102, generating an ion beam that passes through a smaller orifice 112b of the skimmer cone 104 into a vacuum in the mass spectrometer. For example, the orifice 112b can be 0.5 mm, and the orifice 112a can be 1 mm. Methods of operating a general interface assembly for an ICP-MS device are known in the art and are not the focus of the present disclosure, which is directed to the placement of a spacer element between at least one orifice element and a cooling plate 108.

[0031] The skimmer cone 104 and the sampler cone 102 operate at temperatures of several hundred degrees Celsius, so during operation of the mass spectrometer, the components are conditioned to prevent damage from high temperature plasma that can be up to 10,000 °C, and to reduce interference with the sample (e.g., reduce sample deposition). For example, at a plasma power of 1600 W, the temperature at the tip of the skimmer cone 102 can be about 600 °C. To this end, the skimmer cone 104 and the sampler cone 102 are in thermal communication with the cooling plate 108. In particular, as Figure 4In a best-example embodiment, the separator cone 104 is held in a suitable position on the mass spectrometer side of the cooling plate 108 by the retainer 110. The sampler cone 102 is spaced apart from the separator cone 104 and positioned on the opposite side of the cooling plate 108 (the side facing the plasma source). The junction region 103 between the two cones within the junction assembly is maintained at a low pressure, for example, 100 Pa to 300 Pa. Figure 1 As a best example, the transfer assembly 100 is held in the proper position within the spectral analysis apparatus using the fasteners on the cooling plate 108.

[0032] The spacer element 200 is positioned between the separator cone holder 106 and the cooling plate 108, wherein the separator cone holder and the cooling plate are held together by a fastener 110. The separator cone 104 is located at the opening 208 of the spacer element 200. Figure 5a It is located inside and on the separator cone retainer 106. See below for reference. Figure 5a , Figure 5b In more detail, the spacer element 200 is configured such that the electrically isolating body 202 contacts the cooling plate 108 and the conductive layer 204 contacts the separator cone retainer 106. The spacer element 200 also includes an electrical contact tab 206 configured to allow voltage to be supplied to the separator cone 102 through the conductive layer 204 of the spacer element 200. In this way, the separator cone 104 is electrically isolated from the cooling plate 108 and the sampler cone 102, thereby allowing voltage to be supplied to the separator cone 104 without interfering with other components of the transfer assembly 100.

[0033] The temperature of the separator cone 104 will not be set too high, which could damage the components, nor too low, which could interfere with the sample. This is achieved by providing a cooling plate 108, which can be regulated by a (liquid or gaseous) coolant passing through the coolant channel 109 and acts as a heat sink for the separator cone 104. The insulating element 200 that isolates the separator cone 104 from the cooling plate 108 is thin enough and / or thermally conductive to allow heat to be transferred from the separator cone 104 to the cooling plate 108. Other cooling arrangements without coolant channels are also possible, such as providing cooling fins for the cooling plate 108 or an externally applied coolant flow.

[0034] The transfer assembly 100 may also include an O-ring (not shown) positioned between the separator retainer 106 and the separator 104 in the O-ring groove 107, which seals the separator 104 to create a vacuum separation between the plasma source and the mass spectrometer. The O-ring must also be conditioned within the operating temperature range, which can be facilitated by the thermal characteristics of the spacer element 200.

[0035] As discussed above, the spacer element 200 prevents electrical conduction across the interface assembly 100 from the skimmer cone holder 106 to the cooling plate 108 and the sampler cone 102. In this way, the skimmer cone 104 and the skimmer cone holder 106 are electrically isolated. However, it should be appreciated that a spacer element 200 or a second spacer element (not shown) can be positioned between the sampler cone 102 and the cooling plate 108 to electrically isolate the sampler cone 102 from the cooling plate 108 and the skimmer cone 104.

[0036] Figure 5a 、 Figure 5b and Figure 6 Various views of the spacer element 200 are illustrated. Specifically, Figure 5a depicts a face of the spacer element 200 that is configured to contact the skimmer cone assembly, while Figure 5b depicts an opposite face of the spacer element 200 that is configured to abut the cooling plate 108. Figure 6 depicts a cross-sectional view of one possible configuration of the spacer element 200.

[0037] The conductive layer of the spacer element 200 is configured to enable electrical communication with the skimmer cone 104 and / or the skimmer cone holder 106 (although it should be appreciated that alternative options are possible, i.e., contacting and isolating the sampler cone 102). The spacer element includes a conductive layer 204 on top of the electrically isolating body 202. Contact tabs 206 extend from the conductive layer 204 and act as electrical contacts to facilitate the supply of voltage to the conductive layer 204. In some embodiments, the contact tabs are omitted and electrical contact can be made directly on the conductive layer 204. In either case, spring contacts can be used to connect to the conductive layer 204. The conductive layer 204 is circular in shape in order to optimize electrical contact with adjacent interface components (e.g., the skimmer cone holder 106), and is provided with a circumferential gap adjacent to the contact tabs 206 in order to prevent the circular shape from forming a closed electrical loop.

[0038] The spacer element 200 is compact in shape, enabling the effects on the spacing between the skimmer cone 104 and the sampler cone 102 to be minimized. Specifically, the spacer element 200 is substantially planar in order to conform to the components of the interface assembly 100 and achieve a secure fit. For example, the spacer element 200 includes through-holes 114 around its periphery that are configured to accommodate fasteners 110 that attach the skimmer 104 and the skimmer cone holder 106 to the cooling plate 108. The material properties of the spacer element 200 enable the spacing of the skimmer 104 relative to the cooling plate 108 to remain constant during operation of the ICP-MS device, and enable the temperature deviation of the skimmer holder 106 and the skimmer cone 104 to be minimized.

[0039] The outer shape and function of the spacer element 200 advantageously balances the electrical insulation properties with the thermal conduction properties. For example, as Figure 6 In an exemplary embodiment, the spacer element 200 includes a gold layer 302 having a thickness of 3 μιη, a copper foil layer 304 having a thickness of 35 μιη, and a substrate layer 306 having a thickness of 100 μιη.

[0040] The substrate layer 306 has electrical insulation properties and acts as a base for the spacer element 200, enabling the spacer element 200 to electrically insulate the cooling plate 108 and the sampler cone 102 from the separator cone 104.

[0041] The copper foil layer 304 is applied on one side of the polyimide substrate and has a suitable geometry to enable electrical contact with the separator holder 106 and / or the separator cone 104. For example, the copper foil layer 304 can electrically contact the separator holder 106 in electrical communication with the separator cone 104, or alternatively, the copper foil layer 304 of the spacer element 200 can directly contact the separator cone 104.

[0042] When the components of the interface assembly 100 are not inert, reactions can affect the sample measurements and can provide interference at discrete m / z values or as a constant background noise. Without coating, copper can react and typically oxidize. Thus, as Figure 6 In an exemplary embodiment, the copper layer 304 can be provided with a gold layer 302. Advantageously, the gold layer makes the spacer element 200 sufficiently inert so as not to interfere with sample analysis in the mass spectrometer, and conductive to maintain electrical communication with the copper layer 304.

[0043] Advantageously, the manufacture of the layered circuit board is easily reproduced without specialized tools or methods. The spacer element 200 is thus economically manufacturable and manufactured in sufficient quantities.

[0044] Figure 6 The overall thickness of the spacer element 200 of FIG. 1 is 138 μιη, which meets but does not exceed the required heat transfer rate of the separator cone 104. As Figure 6 In an exemplary embodiment, the selection of the material thicknesses is dependent on the surrounding components, i.e., the specific thermal conductivity of the surrounding components of the interface assembly 100, in order to provide the spacer element 200 with a device appropriate thermal conductivity, e.g., as set forth above. In addition to the specific examples set forth, other reasonable materials and thicknesses can be implemented with the spacer element disclosed herein as needed to meet the specific requirements of different spectroscopy devices, without undue experimentation to identify or test such materials and thicknesses.

[0045] In particular, it is to be understood that the above detailed description is intended to be illustrative and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above detailed description. While the disclosure has been described with reference to specific exemplifying embodiments, it will be recognized that the disclosure is not limited to the specific embodiments described, but can be modified and adapted in various ways. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive sense. Therefore, the scope of the disclosure should be determined not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. A spacer element for a plasma interfacing assembly in a spectroscopic analysis device, the interfacing assembly comprising an orifice element defining an orifice for passing plasma from a plasma source and a cooling element for cooling the orifice element, characterised in that, The spacer element comprises: an electrically isolating body configured to be inserted between the orifice element and the cooling element, wherein the electrically isolating body is provided with an opening, and an electrically conductive layer provided on the electrically isolating body to face the orifice element.

2. The spacer element according to claim 1, characterized in that The spacer element further comprises a contact tab extending from the electrically conductive layer, wherein the contact tab is configured to enable an electrical connection with the electrically conductive layer.

3. The spacer element according to claim 2, characterized in that The contact tab extends radially outwardly from the electrically conductive layer.

4. The spacer element according to any one of claims 1 to 3, characterized in that The electrically isolating body is annular in shape so as to allow ions to pass through the orifice when the spacer element is placed between the orifice element and the cooling element.

5. The spacer element according to any one of claims 1 to 3, characterized in that The electrically isolating body has a thickness comprised between 50 pm and 150 pm.

6. The spacer element according to any one of claims 1 to 3, characterized in that The electrically isolating body has a thickness comprised between 90 pm and 110 pm.

7. The spacer element according to any one of claims 1 to 3, characterized in that The electrically isolating body comprises a polyimide layer.

8. The spacer element according to any one of claims 1 to 3, characterized in that The electrically conductive layer comprises a copper foil.

9. The spacer element according to any one of claims 1 to 3, characterized in that The electrically conductive layer comprises a copper track provided on a surface of the electrically isolating body.

10. The spacer element according to any one of claims 1 to 3, characterized in that The electrically conductive layer has a thickness of 30 pm to 40 pm.

11. The spacer element according to any one of claims 1 to 3, characterized in that The spacer element further comprises a gold layer provided on the electrically conductive layer.

12. The spacer element according to claim 11, characterized in that The gold layer has a thickness of 2 pm to 5 pm.

13. The spacer element according to any one of claims 1 to 3, characterized in that The spacer element has a thermal conductivity of 0.1 Watt per meter Kelvin to 0.5 Watt per meter Kelvin.

14. The spacer element according to any one of claims 1 to 3, characterized in that The spacer element further comprises a through hole to accommodate a fixing to secure the orifice element to the cooling element.

15. The spacer element according to any one of claims 1 to 3, characterized in that The cooling element comprises a cooling plate.

16. An interface assembly for a spectrometer comprising an orifice element disposed on a cooling element, characterised in that, The interface assembly comprises a spacer element according to any one of claims 1 to 15 between the orifice element and the cooling element, and an electrical lead to supply a voltage to the orifice element, the electrical lead being connected to the spacer element.

17. The handoff assembly of claim 16, wherein, The orifice element comprises a splitter.

18. The handoff assembly of claim 16 or 17, wherein, The orifice element comprises a sampler.

19. The handoff assembly of claim 16 or 17, wherein, The orifice element comprises a plurality of components including an orifice cone and an orifice cone holder.

20. The handoff assembly of claim 16 or 17, wherein, The cooling element comprises a cooling plate.

21. A spectroscopic analysis device comprising the handoff assembly of any one of claims 16-20, characterized by, The optical spectral analysis device is a mass spectrometer or an optical spectrometer.

22. The optical spectrum analyzer of claim 21, wherein, The cooling element comprises a cooling plate. The cooling element comprises a cooling plate.

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