Microchannel Cartridge for Mass Spectrometers

Abstract

A cartridge assembly for a mass spectrometer includes two detector plates. Each of the two detector plates includes (a) an active area defining a plurality of channels from a first side of each of the two detector plates to a second side of each of the two detector plates, and (b) a plurality of clamping areas. A spacer is disposed between the two detector plates and includes a plurality of clamping tabs aligned with each of the plurality of clamping areas. A washer is disposed proximate to the second detector plate and includes a plurality of clamping blocks aligned with each of the plurality of clamping tabs. A cartridge housing includes a first portion disposed adjacent to the first detector plate and a second portion disposed adjacent to the second detector plate, and a fastener spans the first portion and the second portion. A biasing element is disposed between the washer and the first portion.

Description

[Background technology]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application was filed on April 29, 2022 as a PCT international patent application claiming priority to and the benefit of U.S. Provisional Application No. 63 / 181,522, filed on April 29, 2021, which is incorporated herein by reference.

[0002] background Microchannel plates (MCPs) are planar components used for the detection of single particles (electrons, ions, and neutrons), for example, in mass spectrometer (MS) devices. MCPs are stacked (e.g., in pairs) through which ions pass, where they are multiplied before being delivered to the anode for detection. Stacked MCPs with solid mounting pads, without solid rims, must be carefully assembled within the MCP cartridge. Summary of the Invention [Means for solving the problem]

[0003] overview In one aspect, the present technology relates to a cartridge assembly for a mass spectrometer, the cartridge assembly including: two detector plates, each of the two detector plates including: (a) an active area defining a plurality of channels from a first side of each of the two detector plates to a second side of each of the two detector plates; and (b) a plurality of clamping areas; and a spacer disposed between the two detector plates, the spacer including a plurality of clamping tabs, each of the plurality of clamping tabs being aligned with each of the plurality of clamping areas. The cartridge housing includes a washer disposed adjacent to a second detector plate of the plate, the washer including a plurality of clamp blocks, each of the plurality of clamp blocks being aligned with each of the plurality of clamp tabs; a cartridge housing including a first housing portion disposed adjacent to a first detector plate of the two detector plates and a second housing portion disposed adjacent to a second detector plate of the two detector plates; a plurality of fasteners spanning the first housing portion and the second housing portion; and a biasing element disposed between the washer and the first housing portion. In one example, the plurality of clamp regions are disposed adjacent to a periphery of each of the two detector plates. In another example, the plurality of clamp regions include a channel-less portion of each of the two detector plates. In yet another example, each of the plurality of clamp tabs extends outwardly from a periphery of the spacer. In yet another example, the washer includes an inner ring and an outer ring, and the clamp block extends from the inner ring.

[0004] In another example of the above aspect, the inner ring is elevated relative to the second detector plate.In one example, the biasing element includes an axial canted coil spring disposed proximate to the outer portion of the washer.

[0005] In another aspect, the present technology relates to a cartridge assembly for a mass spectrometer including: an input detector plate defining a plurality of input plate channels extending from an input side of the input detector plate to an output side of the input detector plate; an output detector plate defining a plurality of output plate channels extending from the input side of the output detector plate to an output side of the output detector plate, the input detector plate and the output detector plate being aligned along a common axis; a spacer in contact with the output side of the input detector plate and the input side of the output detector plate; a washer disposed in contact with the output side of the output detector plate; an input housing portion disposed in contact with the input side of the input detector plate; and a biasing element in contact with the washer to bias each of the washer, the output detector plate, the spacer, and the input detector plate toward the input housing portion. In one example, each of the plurality of input plate channels and each of the plurality of output plate channels includes a channel axis disposed at an angle relative to the common axis, an input channel port defined by an input side of each of the input plate and output plates, respectively, and an output channel port defined by an output side of each of the input plate and output plates, respectively. In another example, the plurality of input plate channels includes a housing subset of the input plate channels, where the input channel port of the housing subset of the input plate channels is blocked by an input housing portion, and the output channel port of the housing subset of the input plate channels is unblocked. In yet another example, the plurality of input plate channels includes a spacer subset of the input plate channels, where the input channel port of the spacer subset of the input plate channels is unblocked, and the output channel port of the spacer subset of the input plate channels is blocked by a spacer. In yet another example, the plurality of output plate channels includes a spacer subset of the output plate channels, where the input channel port of the spacer subset of the output plate channels is blocked by a spacer, and the output channel port of the spacer subset of the output plate channels is unblocked.

[0006] In another example of the above aspect, the plurality of output plate channels includes a washer subset of the output plate channels, the input channel openings of the washer subset of the output plate channels are unobstructed, and the output channel openings of the washer subset of the output plate channels are obstructed by a washer. In one example, the output detector plate includes a clamping region characterized by an absence of the plurality of output plate channels. In another example, the washer contacts the clamping region on an output side of the output detector plate, and the spacer contacts the clamping region on an input side of the output detector plate. In yet another example, the biasing element includes an axially canted coil spring having an inner diameter larger than an inner diameter of the washer. In yet another example, the cartridge assembly further includes an output housing portion, and the axially canted coil spring biases the washer away from the output housing portion.

[0007] In another aspect, the present technology relates to a method of assembling a cartridge, the method including: positioning an input detector plate relative to an input housing portion, the input detector plate including a plurality of input plate clamping areas and the input housing portion including a plurality of plate support features; positioning a spacer relative to the input detector plate, the spacer including a plurality of clamp tabs; positioning an output detector plate relative to the spacer, the output detector plate including a plurality of output plate clamping areas; positioning a washer relative to the output detector plate, the washer including a plurality of clamp blocks; positioning a biasing element relative to the washer; and positioning an output housing portion relative to the biasing element, the plurality of plate support features, the plurality of input plate clamping areas, the plurality of clamp tabs, the plurality of output plate clamping areas, and the plurality of clamp blocks are aligned. In one example, the method further includes fastening the output housing portion to the input housing portion, where fastening the output housing portion to the input housing portion applies a biasing force from the biasing element to each of the washer, the output detector plate, the spacer, the input detector plate, and the input housing portion. In another example, the method further includes applying a biasing force with a biasing element proximate a periphery of each of the input housing portion, the input detector plate, the spacer, the output detector plate, and the washer. [Brief description of the drawings]

[0008] [Figure 1A] 1A and 1B show a perspective view and an exploded perspective view of a detector assembly. [Figure 1B] 1A and 1B show a perspective view and an exploded perspective view of a detector assembly.

[0009] [Diagram 2] FIG. 2 shows an exploded perspective view of a microchannel plate (MCP) cartridge used in the detector assembly of FIGS. 1A and 1B.

[0010] [Diagram 3] FIG. 3 shows a top view of the MCP cartridge of FIG. 2, indicating the location of the cross-sectional views of FIGS. 3A and 3B.

[0011] [Figure 3A] FIG. 3A shows a cross-sectional view of the clamping area of ​​the MCP cartridge of FIG.

[0012] [Figure 3B] FIG. 3B shows a cross-sectional view of the non-clamped area of ​​the MCP cartridge of FIG.

[0013] [Figure 4A] FIG. 4A shows a partially enlarged cross-sectional view of a portion of the MCP cartridge of FIG. 3B.

[0014] [Figure 4B] FIG. 4B shows a partially enlarged cross-sectional view of another portion of the MCP cartridge of FIG. 3B.

[0015] [Diagram 5] FIG. 5 illustrates a method for assembling a cartridge for a detector assembly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Detailed Description Careful assembly of the MCP cartridge is important for proper performance and to prevent damage to the MCPs. For example, the MCPs should be clamped to achieve maximum plate flatness. The mounting and stacking configuration must not trap gases within the MCP channels that could cause harmful discharges within the MCP channels. The creepage paths around the edges of each MCP from the top metallization to the bottom metallization should not be shorted by contact with any conductor. The clamping force must be sufficient to prevent movement of the MCP in response to shock and vibration. Finally, electrical contact must be made to the top and bottom MCPs to energize them to perform their electron multiplication functions.

[0017] The cartridges described herein include several features to limit or eliminate damage to the MCP or other components of the MCP cartridge or detector system, or that otherwise improve performance. In an example, the cartridge may include one or more of the following features: The input housing portion may include a plate support mechanism to contact a solid mounting pad or clamping area on the input MCP. The input housing portion may also include an opening with a raised circular lip that contacts the periphery of the input MCP. A similar structure may be present on the output housing portion. The spacer may include clamping tabs that align with clamping areas on the input and output MCPs. A portion of the housing may act as an insulator around the MCP to confine the MCP, align the spacer, insulate the input housing from the output housing, and insulate the edges of the MCP from both housings. A biasing element in the form of a canted coil spring may be utilized to provide a uniform and well-controlled force that presses the washer against the output MCP. The output housing portion compresses and holds the spring, washer, MCP, and spacer in place. The components are constructed so that the microchannels are not blocked at both ends by contacting the components. Alignment markings may be included to facilitate correct angular alignment of the MCP, which may be important to achieve correct ventilation of the channels. Additionally, all parts are made to precise tolerances to ensure flatness.

[0018] As mentioned above, the cartridge configuration described herein ensures that the microchannels are not blocked at both ends. This allows for quicker pump-down to a safe operating state of the detector instrument and minimizes the risk of discharging the MCP. Furthermore, it provides maximum flatness to the input MCP, thus reducing warp-induced jitter in time-of-flight (ToF) measurements. For the detector user, this minimizes pump-down time to a ready state, avoiding the cost and inconvenience of premature MCP failure, and maximizing instrument resolution.

[0019] 1A and 1B show perspective and exploded perspective views of a detector assembly 100 for a mass spectrometer (MS) system and will be described together. The detector 100 includes multiple printed circuit boards (PCBs) 102, 104. As known in the art, the upper PCB 102 can support or include one or more preamplifiers, among other components, and the lower PCB 104 can support or include anodes, transformers, fences, etc., among other components. A potted transformer housing 106 spans the two PCBs 102, 104. One or more support posts 110 provide rigidity to the portions of the PCBs 102, 104 on opposite sides of the housing 106. The base 110 includes one or more fine wire grids, as known in the art, and forms the bottom of the detector assembly 100. Sandwiched between the base 110 and the lower PCB 104 is an MCP cartridge 200, which is described in more detail below. The cartridge 200 is secured to a number of posts 112 that protrude from the base 110. Ions from the mass analyzer portion of the mass spectrometer enter the detector assembly 100 through a grid in the base 110, which functions to shield the mass analyzer from the electric field in the detector. The ions strike an input MCP (described below) in the cartridge 200, generating secondary electrons that are further multiplied in the input and output MCPs. An output pulse of electrons from the MCP is captured on one or more anodes as a current pulse. The current pulse is transmitted through one or more transformers in the housing 106, which isolate the output signal path from the high voltage present on the anode. The current pulse is further amplified and shaped by an electronic preamplifier circuit to generate an output pulse from the detector.

[0020] FIG. 2 shows an exploded perspective view of the MCP cartridge 200 used in the detector assembly of FIGS. 1A and 1B. It will be understood that ions enter the detector assembly of FIGS. 1A and 1B (and thus the cartridge 200 of FIG. 2) from below, and electrons that pass through the cartridge exit at its output side. This flow of ions is illustrated in FIGS. 2-3B by the input I and output O arrows. Thus, in FIGS. 2-3B, each described component has both an input side (generally the lower side of said component) and an output side (generally the upper side of said component). Furthermore, where multiple components of the same or similar type (or multiple parts of the same component) are utilized, they may also be described as being "input" or "output" components, depending on their relative positions within the MCP cartridge 200, as described below. Furthermore, the various components are aligned along a common axis A. With these relative positions in mind, FIG. 2 will now be described in detail.

[0021] The cartridge 200 includes multiple components that form its housing 202. The input housing portion of the housing includes components 202a and 202b. Both input housing portions 202a and 202b define openings 204a, 204b therein. The lower input housing portion 202a includes multiple flanges 206 that can be secured to the posts 112 shown in FIGS. 1A and 1B, for example, using mechanical fasteners. The upper input housing portion 202b can be secured to the lower input housing portion 202a using one or more fasteners, such as screws or bolts 208. In other examples, other types of mechanical fasteners (such as press-fit or interference-fit fasteners), adhesives, or combinations thereof, may be used to secure the two input housing portions 202a (acting as conductors), 202b (acting as insulators). The two input housing portions 202a act as conductors of voltage to the input MCP 212 and include a number of plate supports 210, four of which are shown in FIG. 2. The plate supports 210 are disposed proximate the opening 204a and may include protrusions, flanges, or other enlarged portions configured and arranged to contact respective predetermined portions of the input MCP 212. In an example, the input housing portion 202b acts as an insulator and defines an opening 204b which may include a perimeter configured to receive and align other components of the cartridge 200.

[0022] The input MCP 212 is a microchannel plate, a planar component used for the detection of single particles (e.g., ions, electrons, neutrons, etc.) and low intensity impinging radiation. The input MCP 212 includes a body 214 made from a highly resistive material and may have a thickness of about 2 mm. The body 214 includes a regular array of small tubes or slots (e.g., microchannels) in a so-called "active area" of the body 214. The active area is not specifically shown, but may be considered as any part of the body 214 in which one or more microchannels are present. Each microchannel is defined on the input side of the input MCP 212 by an input channel port and on the output side of the input MCP 212 by an output channel port. The microchannels are densely distributed over a significant portion of the surface of the body 214 and may be about 5 micrometers in diameter. The microchannels may be spaced about 6 micrometers apart and may be distributed substantially parallel to one another. In an example, the microchannels may enter the MCP 212 at a small angle to the surface (e.g., about 12° from normal) or orthogonal to it (e.g., when the input beam is at an angle to the MCP 212). The microchannels cannot be shown precisely in Figure 2 due to their small size, but a circular distribution of one of the microchannels 216 is shown enlarged for illustrative purposes.

[0023] The input MCP 212 also includes a number of clamping areas 218 disposed proximate or around the periphery of the input MCP 212. Although four clamping areas 218 are shown, any number may be utilized. The clamping areas 218 are characterized by the absence of any microchannels 216 therein, thus rendering the clamping areas 218 channel-less. When the cartridge 200 is assembled, each clamping area 218 is aligned with one of the plate support features 210 on the input housing portions 202a, 202b. As described in more detail herein, this alignment helps ensure that the clamping force of the cartridge 200 is distributed to the appropriate areas of the input MCP 212.

[0024] The spacer 220 is disposed adjacent to the input MCP 212. The spacer 220 includes an outer diameter Dso that is smaller than the outer diameter of the input MCP 212. A plurality of clamp tabs 222 extend from a periphery or periphery of the spacer 220. When the cartridge 200 is assembled, each clamp tab 222 is aligned with one of the clamp areas 218 on the input MCP 212. Additionally, the spacer 220 defines a central opening 224 that can at least partially define a significant portion of the active area described above (with respect to the input MCP 212). More specifically, the opening 224 is sized such that a majority of the microchannels in the input MCP 212 are not blocked by the spacer 220 itself. The microchannels must not be completely blocked on both the input and output sides to detect ions. It may be advantageous to size the spacer 220 and position the microchannels such that as many microchannels as possible are not blocked on both sides. The clamp tabs 222 are constructed and arranged to contact respective predetermined portions of the output MCP 226 .

[0025] The output detector plate 226 is a microchannel plate substantially similar or identical to the input MCP 212. The output MCP 226 also includes a number of clamping areas 232 disposed proximate to or around the periphery of the input MCP 226. Although four clamping areas 232 are shown, any number may be utilized. The clamping areas 232 are characterized by the absence of any microchannels 230 therein, thus making the clamping areas 232 "channel-less." When the cartridge 200 is assembled, each clamping area 232 is aligned with one of the clamp tabs 222 on the spacer 220. As described in more detail herein, this alignment helps ensure that the clamping force of the cartridge 200 is distributed to the appropriate area of ​​the output MCP 226.

[0026] The washer 234 is disposed adjacent to the output MCP 226. The washer 234 includes an inner ring 236 and an outer ring 238, which will be further described with reference to FIGS. 3A, 3B, and 4B. The washer 234 also includes a number of clamp blocks 240 (not shown, but located in dashed areas 240) on the input side of the washer 234. When the cartridge 200 is assembled, each clamp block 240 is aligned with one of the clamp areas 232 on the output MCP 226. Additionally, the washer 234 defines a central opening 242 that can at least partially encompass a significant portion of the active area of ​​the output MCP 226. More specifically, the opening 242 is sized such that a majority of the microchannels in the output MCP 226 are not blocked by the washer 234 itself. The microchannels must not be completely blocked on both the input and output sides to detect ions. It may be advantageous to size the washer 234 and position the microchannels such that as many of the microchannels as possible are unblocked on both sides. The washer 234 is positioned to contact the biasing element 244 along substantially the entirety of its output face.

[0027] The biasing element 244 may be an axially canted coil spring in contact with the washer 234, distributing the biasing force evenly across the washer 234. Thus, the distribution of force on the remaining components between the washer 234 and the input housing portion 202a, 202b also remains uniform and consistent. The force of the spring biasing element 244 on the washer 234 is at least partially caused by the contact between the spring 244 and the output housing portion 246. The outer housing portion 246 includes a number of flanges 248 configured to accept mechanical fasteners 250, such as bolts or screws. The bolts or screws 250 extend from the output housing portion 248 and are secured to the input housing portions 202a, 202b to pull the two housing portions 248, 202a, 202b together. This causes the force of the spring 244 to be evenly applied to the internal components of the cartridge 200. In particular, the force is applied primarily along the contact surfaces of the various components, namely, clamp block 240 , clamp area 232 , clamp tabs 222 , clamp area 218 , and plate support mechanism 210 .

[0028] FIG. 3 shows a top view of the MCP cartridge 200 of FIG. 2, indicating the location of the cross-sectional views shown in FIGS. 3A and 3B. The components shown in FIG. 3A have been described above in connection with FIG. 2 and will not necessarily be described further. In the top view, the output MCP 226 is visible through an opening defined by the output housing portion 246. FIG. 3A shows a cross-sectional view of the clamping region of the MCP cartridge 200 of FIG. 3, the input and output sides of which have been described above for various components, and the input I and output O arrows are also shown for illustrative purposes to indicate the direction of ion movement into the opening 204a of the input housing portion 206a. The spring 244 is at least partially disposed within a recess 252 formed in the output housing portion 246. The recess 252 has a height that is less than the undeformed height of the spring 244. Thus, when the cartridge 200 is assembled, the spring 244 is compressed between the output housing portion 246 and the washer 234 (e.g., its outer ring 238). This creates and evenly distributes a downward compressive force F against other components of the cartridge 200, as described above.

[0029] The spring force is distributed downward (towards the input I side) evenly adjacent to the periphery of the input MCP 214 and the output MCP 226, but the cartridge 200 is configured such that the compressive force F is transmitted through a specific location of the cartridge 200 (approximately aligned with the clamping areas 232, 218). In relation to this distribution of compressive force F, FIG. 3A also shows the clamping block 240 described above with respect to FIG. 2. The clamping block 240 is an enlarged portion of the washer 234 adjacent to the inner ring 236 below it, which allows for a more uniform transmission of the compressive force F from the spring 244. The compressive force F passes through a path defined by the clamping area 232 of the output MCP 226, the clamping tabs 222 of the spacer 220, the clamping area 218 of the input detector plate 214, and the plate support mechanism 210 of the input housing portion 206a. As described above, the clamping areas 232, 218 are characterized by an absence of microchannels therein. Thus, the microchannel plates 232, 218 are permitted to be contacted on both sides by other structures (e.g., clamping block 240 and clamping tabs 222). Because there are no microchannels in these clamping areas 232, 218, there is no risk of gas accumulating therein. Lateral movement of the input detector plate 214, output MCP 226, and other components is prevented by their location within the input housing portion 206b.

[0030] FIG. 3B shows a cross-sectional view of the non-clamped area of ​​the MCP cartridge 200 of FIG. 3. Some of the components shown in FIG. 3B have been described above in connection with FIG. 2 and FIG. 3A and will not necessarily be described further. One notable difference between the cross-sectional view of the non-clamped area of ​​FIG. 3B is the absence of the clamp block 240, the clamp area 232, the clamp tab 222, and the clamp area 218, all of which are seen in FIG. 3A. As such, since a portion of the spacer 220 is in contact with the input detector plate 214 and the output MCP 226, it is important that the microchannels blocked on one side by the spacer 220 are not blocked on the other side, which could result in gas accumulation therein. Thus, as can be seen in FIG. 3B, in the areas of the input detector plate 214 and the output MCP 226 that contact the spacer 220, the washer 234, or the input housing portion 206a, the contact of those elements is only on one side, thus ensuring that the microchannels at those locations are not blocked on both sides. This condition is shown in more detail in FIG. 4A.

[0031] FIG. 4A shows a partial enlarged cross-sectional view of the MCP cartridge 200 of FIG. 3. For purposes of illustration, the relevant portion of the cartridge includes the input MCP 214, which defines several microchannels 302 therethrough. The microchannels 302 are shown as straight lines for simplicity, more often the microchannels (or individual portions thereof) are disposed at an angle to the side of the MCP 214. FIG. 4A also shows an obstruction element, in this case a spacer 220. In other locations, the obstruction element may be a plate support structure (associated with the input MCP), or a spacer or washer (associated with the output MCP), or some other component. In general, an "obstruction element" may be located on the input side I or the output side O of a particular MCP. Each channel 302 includes an input channel port 304 and an output channel port 306. At least one port 304, 306 of each microchannel 304 must remain unblocked to ensure removal of residual gases, thereby preventing potentially damaging discharges. If the vacuum pressure in the microchannel is not low enough before applying the high voltage to the MCP 214, a glow discharge may form in the microchannel. Power loss in the glow discharge will cause localized thermal damage to the MCP 214. Thus, for microchannel 302a, both input channel port 304a and output channel port 306a are unblocked. For microchannel 302b, input channel port 304b is unblocked, but output channel port 306b is blocked.

[0032] FIG. 4B shows a partial enlarged cross-sectional view of another portion of the MCP cartridge 200 of FIG. 3. Some components shown in FIG. 4B have been described above in connection with FIGS. 3A-3B (and other figures) and therefore will not necessarily be described further. As described above, the washer 234 includes an inner ring 236 and an outer ring 238. The inner ring 236 is defined in part by an inner ring output recess 308 and an inner ring input recess 310. The inner ring output recess 308 provides clearance to accommodate the output housing portion 246 when compressed downwardly on the biasing element 244. The inner ring input recess 310 effectively raises the bottom of the washer 234 that would otherwise be disposed above the spacer 220. If that inner ring input recess 310 was not present, the microchannel below would be blocked both above (by the washer 234) and below (by the spacer 220). 3A where clamp block 240 is in contact with clamping area 232. Washer 345 also includes an outer ring input recess 312 located above the periphery of output MCP 226. The absence of washer material in this location prevents contact between washer 234 and the exposed edge of output MCP 226, thereby shorting out voltage. A similar input housing portion recess 314 is defined by input housing portion 206a to prevent contact with and shorting out input MCP 214.

[0033] FIG. 5 illustrates a method 500 of assembling a cartridge for a detector assembly. Method 500 begins with operation 502, positioning an input detector plate relative to an input housing portion. The input detector plate includes a number of input plate clamping areas that may be evenly distributed around its circumference. Additionally, the input housing portion includes a number of plate support features, preferably the same number as the number of input plate clamping areas. Flow proceeds to operation 504, positioning a spacer relative to the input detector plate. The spacer includes a number of clamp tabs, again similar to the number of clamping areas. In operation 506, positioning an output detector plate relative to the spacer is performed. The output detector plate also includes a number of output plate clamping areas, again corresponding to the number of input plate clamping areas. In operation 508, positioning a washer relative to the output detector plate is performed. The washer includes a number of clamp blocks equal to the number of clamping areas. Operation 510 includes positioning a biasing element relative to the washer, examples of which are described elsewhere herein. Operation 512 includes positioning an output housing portion relative to the biasing element. Due to the resiliency of the biasing element, this action also applies a biasing force from the biasing element to each of the washers, output detector plate, spacer, input detector plate, and input housing portion, which are all aligned. The biasing force is applied closely around each of the identified elements, taking into account the relative positions of the various contacting components. To complete the assembly of the cartridge, action 514 is performed, namely fastening the output housing portion to the input housing portion. This action secures the housings together and may also further apply and adjust the biasing force as the radial spring is further compressed.

[0034] This disclosure has described several examples of the present technology with reference to the accompanying drawings, which illustrate only a few of the possible examples. However, other aspects may be embodied in many different forms and should not be construed as being limited to the examples set forth herein. Rather, these examples are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the possible examples to those skilled in the art.

[0035] Although specific examples have been described herein, the scope of the technology is not limited to those specific examples. Those skilled in the art will recognize other examples or improvements that are within the scope of the technology. Thus, specific structures, operations, or media are disclosed only as examples for illustration purposes. Examples according to the technology can also combine elements or components that are generally disclosed but not explicitly illustrated in combination, unless otherwise stated herein. The scope of the technology is defined by the following claims and equivalents therein.

[0036] The following is claimed:

Claims

1. 1. A cartridge assembly for a mass spectrometer, the cartridge assembly comprising: two detector plates, each of the two detector plates comprising: (a) an active area defining a plurality of channels from a first side of each of the two detector plates to a second side of each of the two detector plates; and (b) a plurality of clamping areas; a spacer disposed between the two detector plates, the spacer comprising a plurality of clamp tabs, each of the plurality of clamp tabs aligned with a respective one of the plurality of clamp regions; a washer disposed proximate to a second of the two detector plates, the washer comprising a plurality of clamp blocks, each of the plurality of clamp blocks aligned with a respective one of the plurality of clamp tabs; A cartridge housing, the cartridge housing comprising: a first housing portion disposed adjacent to a first of the two detector plates; a second housing portion disposed adjacent to the second detector plate; a cartridge housing comprising: a plurality of fasteners spanning the first housing portion and the second housing portion; a biasing element disposed between the washer and the first housing portion; A cartridge assembly comprising:

2. The cartridge assembly of claim 1 , wherein the plurality of clamping regions are disposed proximate the periphery of each of the two detector plates.

3. The cartridge assembly of claim 1 , wherein the plurality of clamping regions comprises a channel-free portion of each of the two detector plates.

4. The cartridge assembly of claim 1 , wherein each of the plurality of clamp tabs extends outwardly from a periphery of the spacer.

5. The cartridge assembly of claim 1 , wherein the washer comprises an inner ring and an outer ring, the clamp block extending from the inner ring.

6. The cartridge assembly of claim 5 , wherein the inner ring is raised relative to the second detector plate.

7. The cartridge assembly of claim 1 , wherein the biasing element comprises an axially canted coil spring disposed proximate an outer portion of the washer.

8. 1. A cartridge assembly for a mass spectrometer, the cartridge assembly comprising: an input detector plate defining a plurality of input plate channels extending from an input side of the input detector plate to an output side of the input detector plate; an output detector plate, the output detector plate defining a plurality of output plate channels extending from an input side of the output detector plate to an output side of the output detector plate, the input detector plate and the output detector plate being aligned along a common axis; a spacer contacting the output side of the input detector plate and the input side of the output detector plate; a washer disposed in contact with the output side of the power detector plate; an input housing portion disposed in contact with the input side of the input detector plate; a biasing element contacting the washer for biasing each of the washer, the output detector plate, the spacer, and the input detector plate toward the input housing portion; A cartridge assembly comprising:

9. Each of the plurality of input plate channels and each of the plurality of output plate channels a channel axis disposed at an angle relative to said common axis; an input channel mouth defined by the input sides of each of the input and output plates, respectively; an output channel opening defined by the output sides of each of the input and output plates, respectively; The cartridge assembly of claim 8 , comprising:

10. 10. The cartridge assembly of claim 9, wherein the plurality of input plate channels comprises a housing subset of input plate channels, the input channel openings of the housing subset of input plate channels being blocked by the input housing portion, and the output channel openings of the housing subset of input plate channels being unblocked.

11. 10. The cartridge assembly of claim 9, wherein the plurality of input plate channels comprises a spacer subset of input plate channels, the input channel openings of the spacer subset of input plate channels being unblocked and the output channel openings of the spacer subset of input plate channels being blocked by the spacers.

12. 10. The cartridge assembly of claim 9, wherein the plurality of output plate channels comprises a spacer subset of output plate channels, the input channel openings of the spacer subset of output plate channels being blocked by the spacers and the output channel openings of the spacer subset of output plate channels being unblocked.

13. 10. The cartridge assembly of claim 9, wherein the plurality of output plate channels comprises a washer subset of output plate channels, the input channel openings of the washer subset of output plate channels being unblocked and the output channel openings of the washer subset of output plate channels being blocked by the washers.

14. The cartridge assembly of claim 8 , wherein the output detector plate comprises a clamping region characterized by an absence of the plurality of output plate channels.

15. The cartridge assembly of claim 14 , wherein the washer contacts the clamping area on an output side of the power detector plate and the spacer contacts the clamping area on an input side of the power detector plate.

16. The cartridge assembly of claim 8 , wherein the biasing element comprises an axially canted coil spring having an inner diameter larger than an inner diameter of the washer.

17. The cartridge assembly of claim 16, further comprising an output housing portion, said axial canted coil spring biasing said washer away from said output housing portion.

18. 1. A method of assembling a cartridge, the method comprising: positioning an input detector plate relative to an input housing portion, the input detector plate comprising a plurality of input plate clamping areas, the input housing portion comprising a plurality of plate support mechanisms; positioning a spacer relative to the input detector plate, the spacer comprising a plurality of clamp tabs; positioning a power detector plate relative to the spacer, the power detector plate comprising a plurality of power plate clamping regions; positioning a washer relative to the power detector plate, the washer comprising a plurality of clamp blocks; positioning a biasing element relative to the washer; positioning an output housing portion relative to the biasing element, wherein the plurality of plate support mechanisms, the plurality of input plate clamping areas, the plurality of clamp tabs, the plurality of output plate clamping areas, and the plurality of clamp blocks are aligned; A method comprising:

19. 20. The method of claim 18, further comprising fastening the output housing part to the input housing part, wherein fastening the output housing part to the input housing part applies a biasing force from the biasing element to each of the washer, the output detector plate, the spacer, the input detector plate, and the input housing part.

20. 20. The method of claim 18, further comprising applying a biasing force with the biasing element proximate a periphery of each of the input housing portion, the input detector plate, the spacer, the output detector plate, and the washer.

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