US4456487A
Expired / Lapsed
US
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Method for cleaning and annealing a thermoluminescent radiation detector crystal
Assignee: Siemens Gammasonics Inc
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Filing: 1982-06-10
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Granted: 1984-06-26
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Expires: 2002-06-10
Abstract
Abstract A thermoluminescent radiation detector crystal which has been irradiated by ionizing radiation is contacted with an organic solvent at its boiling point prior to read-out of the crystal. The boiling point of the solvent is approximately equal to the optimum post-radiation annealing temperature of the crystal. The solvent thereby simultaneously cleans and anneals the crystal. Preferably, the contacting step is performed by suspending the crystal in vapors of the solvent. The vapor condenses on the crystal and washes away impurities from the surface thereof.
Inventors
- 👤 Robert W. Pollock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:10
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/02; G01T1/10; G01T1/11; G01T1/115; B; B08; B08B; B08B11/00
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
71 words
A method for processing a thermoluminescent radiation detector crystal which has been irradiated by ionizing radiation, comprising the step of contacting said irradiated crystal prior to read-out thereof with an organic solvent at its boiling point for a time sufficient to clean and anneal said irradiated crystal, said boiling point being approximately equal to the optimum post-radiation annealing temperature of said crystal, said solvent thereby simultaneously cleaning and annealing said crystal.
Claim 2
Independent Claim
71 words
A method for processing a thermoluminescent radiation detector crystal which has been irradiated by ionizing radiation, comprising the step of contacting said irradiated crystal prior to read-out thereof with an organic solvent at its boiling point for a time sufficient to clean and anneal said irradiated crystal, said boiling point being approximately equal to the optimum post-radiation annealing temperature of said crystal, said solvent thereby simultaneously cleaning and annealing said crystal.
Claim 3
Dependent Claim
18 words
The method according to claim 1, wherein said crystal is suspended in a vapor bath of said solvent.
Claim 4
Dependent Claim
29 words
The method according to claim 1, wherein said crystal is a lithium fluoride crystal which is exposed to said solvent at approximately 100° C. for at least 10 minutes.
Claim 5
Dependent Claim
29 words
The method according to claim 1, wherein said crystal is a calcium fluoride crystal which is exposed to said solvent at approximately 100° C. for at least 20 minutes.
Claim 6
Independent Claim
14 words
The method according to claims 3 or 4, wherein said solvent is sec-butyl alcohol.
Claim 7
Independent Claim
14 words
The method according to claims 3 or 4, wherein said solvent is methyl cyclohexane.
Claim 8
Independent Claim
15 words
The method according to claims 3 or 4, wherein said solvent is ethyl tert-amyl ether.
Claim 9
Dependent Claim
25 words
The method according to claim 1, wherein the boiling point of said solvent is within a range of ±2° C. of said optimum annealing temperature.
Claim 10
Dependent Claim
26 words
The method according to claim 1, further comprising the step of subsequently reading out data with respect to effects of said ionizing radiation on said crystal.
Claim 11
Dependent Claim
12 words
The method according to claim 1, wherein said radiation is gamma radiation.
Claim 12
Dependent Claim
12 words
The method according to claim 1, wherein said radiation is beta radiation.
Claim 13
Dependent Claim
17 words
The method according to claim 1, wherein said crystal is the detector crystal of a thermoluminescence dosimeter.
References Cited (Backward Citations)
US2550173A
Cited
US3437521A
Cited
US3414423A
Cited
US3516861A
Cited
US3590245A
Cited
US3790784A
Cited
US3904102A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-26 | 1987-12-26 | 1988-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-26 | 1991-12-26 | 1992-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-26 | 1995-12-26 | 1996-06-26 | $7700.00 | Window Closed / Lapsed |