US5075555A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Peltier cooled lithium-drifted silicon x-ray spectrometer
Assignee: KEVEX INSTRUMENTS A CA CORP
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Filing: 1990-08-10
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Granted: 1991-12-24
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Expires: 2010-08-10
Abstract
Abstract For use as a substitute for liquid nitrogen cooled energy dispersive x-ray detection in spectrometry, the present invention comprises a cooper cold-finger having a lithium-drifted silicon detector and FET at one end, and a five-stage Peltier cooling stack thermally connected to the fifth stage through copper braid at the other end, an aluminum heat shield surrounding the cold-finger and thermally connected to the fourth stage of the Peltier cooling stack with a copper braid, a plurality of nylon spiders that support the cold finger within the heat shield and isolate them thermally, a stainless steel cap, a plurality of nylon spiders that support the heat shield within the cap and thermally isolates them, a heat sink in thermal communication with the hot end of the cooling stack, a remote water cooling system piped to the heat sink and mechanically isolated from vibrating the silicon detector, an ion pump to create a high-quality vacuum around the silicon detector, a motor drive to adjust the reach of the silicon detector assembly, a heat sensor, and a tip proximity sensor.
Inventors
- 👤 Rolf Woldseth
- 👤 Richard J. Bosson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 03:08
CPC Classifications
F; F25; F25B; F25B21/00; F25B21/02; G; G01; G01T; G01T1/00; G01T1/16; G01T1/24; G01T1/244; H; H10; H10F; H10F30/00; H10F30/20; H10F30/29; H10F30/292; H10F30/2925; H10F77/00; H10F77/60; H10N; H10N10/00
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
113 words
A method of protecting a Peltier cooling stack from breaking, comprising the steps of: supporting a cold finger, having at one end a lithium-drifted silicon detector, within a heat shield means for cutting down radiant heat absorption in said cold finger with a means for thermally isolating conductive heat flowing to said cold finger from said heat shield means; connecting said cold finger to a stage of the Peltier cooling stack by a thermally conductive means for transferring heat, said thermally conductive means being flexible; and connecting said heat shield means to a stage of the Peltier cooling stack by a thermally conductive means for transferring heat, said thermally conductive means being flexible.
Claim 2
Independent Claim
113 words
A method of protecting a Peltier cooling stack from breaking, comprising the steps of: supporting a cold finger, having at one end a lithium-drifted silicon detector, within a heat shield means for cutting down radiant heat absorption in said cold finger with a means for thermally isolating conductive heat flowing to said cold finger from said heat shield means; connecting said cold finger to a stage of the Peltier cooling stack by a thermally conductive means for transferring heat, said thermally conductive means being flexible; and connecting said heat shield means to a stage of the Peltier cooling stack by a thermally conductive means for transferring heat, said thermally conductive means being flexible.
Claim 3
Dependent Claim
22 words
The method of claim 1, wherein: connecting said thermally conductive means to said cold finger comprises using at least one copper braid.
Claim 4
Dependent Claim
23 words
The method of claim 1, wherein: connecting said thermally conductive means to said heat shield means comprises using at least one copper braid.
Claim 5
Dependent Claim
25 words
The method of claim 1, wherein: connection of said cold finger to said cooling stack is made at the coldest stage of said cooling stack.
Claim 6
Dependent Claim
27 words
The method of claim 1, wherein: connection of said heat shield means to said cooling stack is made at the second coldest stage of said cooling stack.
Claim 7
Independent Claim
99 words
A method of eliminating vibration caused by a lithium-drifted silicon detector within a scanning electron microscope, comprising the steps of: cooling the lithium-drifted silicon detector with a multi-stage Peltier cooling stack; mounting said multi-stage Peltier cooling stack to a means for heat sinking; cooling said means for heat sinking with a closed circuit flow of liquid having a high specific heat; and cooling said liquid by means of a radiator having a forced air flow mechanically and physically remote from said lithium-drifted silicon detector such that vibrations in the cooling system are substantially isolated from said lithium-drifted silicon detector.
Claim 8
Independent Claim
99 words
A method of eliminating vibration caused by a lithium-drifted silicon detector within a scanning electron microscope, comprising the steps of: cooling the lithium-drifted silicon detector with a multi-stage Peltier cooling stack; mounting said multi-stage Peltier cooling stack to a means for heat sinking; cooling said means for heat sinking with a closed circuit flow of liquid having a high specific heat; and cooling said liquid by means of a radiator having a forced air flow mechanically and physically remote from said lithium-drifted silicon detector such that vibrations in the cooling system are substantially isolated from said lithium-drifted silicon detector.
Claim 9
Dependent Claim
74 words
The method of claim 6, further comprising the steps of: connecting the lithium-drifted silicon detector with a cold finger to a stage of said multi-stage Peltier cooling stack by a flexible and thermally conductive means for transferring heat; and surrounding said cold finger with a heat shield means for reducing transfer of heat by radiation to a stage of said multi-stage Peltier cooling stack by a flexible and thermally conductive means for transferring heat.
Claim 10
Dependent Claim
30 words
The method of claim 6, further comprising the steps of: dampening any pulses in said closed circuit flow of said liquid with a means for smoothing hydraulic pressures over time.
Claim 11
Dependent Claim
189 words
An energy dispersive x-ray spectrometer, comprising: a lithium-drifted silicon detector; a FET preamplifier in communication with the detector; a cold finger having a first end adapted for mounting of the detector and the FET and a second end; a heat shield means for reducing radiant heat transfer, the heat shield means having disposed within it the cold finger; a cap having disposed within it the heat shield means, the heat shield being supported within the cap by a plurality of insulating spiders; a multi-stage Peltier cooling stack in thermal communication at a cold end with said second end of the cold finger, and at a hot end with a heat sink; a cooling system physically and mechanically remote from an assembly comprising the lithium drifted silicon detector, the cooling system having a closed circuit flow of liquid through said heat sink; connecting means for thermally connecting the cold finger to the cooling stack, the connecting means substantially reducing the ability of the cold finger to act as a lever and crack the Peltier cooling stack; and flexible means for thermally connecting the heat shield means to the cooling stack.
Claim 12
Dependent Claim
189 words
An energy dispersive x-ray spectrometer, comprising: a lithium-drifted silicon detector; a FET preamplifier in communication with the detector; a cold finger having a first end adapted for mounting of the detector and the FET and a second end; a heat shield means for reducing radiant heat transfer, the heat shield means having disposed within it the cold finger; a cap having disposed within it the heat shield means, the heat shield being supported within the cap by a plurality of insulating spiders; a multi-stage Peltier cooling stack in thermal communication at a cold end with said second end of the cold finger, and at a hot end with a heat sink; a cooling system physically and mechanically remote from an assembly comprising the lithium drifted silicon detector, the cooling system having a closed circuit flow of liquid through said heat sink; connecting means for thermally connecting the cold finger to the cooling stack, the connecting means substantially reducing the ability of the cold finger to act as a lever and crack the Peltier cooling stack; and flexible means for thermally connecting the heat shield means to the cooling stack.
Claim 13
Dependent Claim
14 words
The spectrometer of claim 9, wherein: the cold finger is comprised of solid copper.
Claim 14
Dependent Claim
17 words
The spectrometer of claim 9, wherein: the heat shield means is comprised of a tube of aluminum.
Claim 15
Dependent Claim
15 words
The spectrometer of claim 9, wherein: the connecting means comprises at least one copper braid.
Claim 16
Dependent Claim
15 words
The spectrometer of claim 9, wherein: the flexible means comprises at least one copper braid.
Claim 17
Dependent Claim
12 words
The spectrometer of claim 9, wherein: said liquid is substantially all water.
Claim 18
Dependent Claim
16 words
The spectrometer of claim 9, wherein: the multi-stage Peltier cooling stack has at least five stages.
Claim 19
Dependent Claim
32 words
The spectrometer of claim 9, further comprising: a vacuum means for pumping down a vacuum of at least 10 -8 torr, the vacuum surrounding the lithium-drifted silicon detector and within the cap.
Claim 20
Dependent Claim
23 words
The spectrometer of claim 9, further comprising: a boron-nitride window through which photons may pass before being absorbed in the lithium-drifted silicon detector.
Claim 21
Dependent Claim
26 words
The spectrometer of claim 9, further comprising: a positioning means for adjusting the depth of entry of the lithium-drifted silicon detector into a scanning electron microscope.
Claim 22
Dependent Claim
11 words
The spectrometer of claim 9, further comprising: a scanning electron microscope.
Claim 23
Dependent Claim
56 words
The spectrometer of claim 9, further comprising: an adapter means able to effectively lengthen and shorten the reach of the cap beyond an adaptor plate, the adaptor means able stop if the cap should come into contact with a foreign object, and the adaptor means able to withdraw the spectrometer from a scanning electron microscope (SEM).
Claim 24
Dependent Claim
15 words
The spectrometer of claim 9, further comprising: a guard ring around the lithium-drifted silicon detector.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-23 | 1995-06-24 | 1995-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-23 | 1999-06-24 | 1999-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-23 | 2003-06-24 | 2003-12-24 | $7700.00 | Window Closed / Lapsed |