US4636642A
Expired / Lapsed
US
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Thin thermoluminescent dosimeter and method of making same
Assignee: Kansas State University
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Filing: 1984-02-13
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Granted: 1987-01-13
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Expires: 2004-02-13
Abstract
Abstract An improved thermoluminescent ionizing radiation dosimeter of solid, extremely thin construction for more accurate low energy beta dosimetry is provided, along with a method of fabricating the dosimeter. In preferred forms, the dosimeter is a composite including a backing support (which may be tissue equivalent) and a self-sustaining body of solid thermoluminescent material such as LiF having a thickness of less than about 0.25 millimeters and a volume of at least about 0.0125 mm 3 . In preferred fabrication procedures, an initially thick (e.g., 0.89 millimeters) TLD body is wet sanded using 600 grit or less sandpaper to a thickness of less than about 0.25 millimeters, followed by adhesively attaching the sanded body to an appropriate backing. The sanding procedure permits routine production of extremely thin (about 0.05 millimeters) TLD bodies, and moreover serves to significantly reduce non-radiation-induced thermoluminescence. The composite dosimeters are rugged in use and can be subjected to annealing temperatures for increased accuracy.
Inventors
- 👤 Gale G. Simons
- 👤 Timothy M. DeBey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:43
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/02; G01T1/10; G01T1/11
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
38 words
A radiation dosimeter comprising an essentially pure, self-sustaining, solid body of thermoluminescent material of substantially constant density and having a thickness of less than about 0.15 millimeters and a volume of at least about 0.0125 mm 3 .
Claim 2
Dependent Claim
38 words
A radiation dosimeter comprising an essentially pure, self-sustaining, solid body of thermoluminescent material of substantially constant density and having a thickness of less than about 0.15 millimeters and a volume of at least about 0.0125 mm 3 .
Claim 3
Dependent Claim
19 words
The dosimeter of claim 1, said body having length and width dimensions of at least about 0.5 millimeters respectively.
Claim 4
Dependent Claim
16 words
The dosimeter of claim 2, said length and width dimensions being at least about 3 millimeters.
Claim 5
Dependent Claim
13 words
The dosimeter of claim 1, said thickness being less than about 0.05 millimeters.
Claim 6
Dependent Claim
13 words
The dosimeter of claim 1, said body presenting at least one sanded face.
Claim 7
Dependent Claim
14 words
The dosimeter of claim 1, said body presenting a pair of opposed sanded faces.
Claim 8
Dependent Claim
20 words
The dosimeter of claim 1, including a block for said body, and means for securing said body to said block.
Claim 9
Dependent Claim
46 words
The dosimeter of claim 1, said material being selected from the group consisting of nat LiF, 7 LiF, 6 LiF, Li 2 B 4 O 7 , CaSO 4 , CaF 2 , MgB 4 O 7 , doped species of the foregoing, and mixtures thereof.
Claim 10
Dependent Claim
18 words
The dosimeter of claim 1, said body having a volume of at least about 0.5 mm 3 .
Claim 11
Dependent Claim
16 words
The dosimeter of claim 9, said volume being from about 0.0125 to 2.5 mm 3 .
Claim 12
Dependent Claim
19 words
The dosimeter of claim 1, said body being in the form of a pressed or extruded initially powder material.
Claim 13
Independent Claim
47 words
A method of fabricating a radiation dosimeter comprising the steps of: providing a solid, self-sustaining body of thermoluminescent material having a substantially constant density; and physically abrading at least one surface of said body in order to reduce the thickness thereof to less than about 0.15 millimeters.
Claim 14
Independent Claim
47 words
A method of fabricating a radiation dosimeter comprising the steps of: providing a solid, self-sustaining body of thermoluminescent material having a substantially constant density; and physically abrading at least one surface of said body in order to reduce the thickness thereof to less than about 0.15 millimeters.
Claim 15
Dependent Claim
17 words
The method of claim 12, said abrading step comprising sanding at least one face of said body.
Claim 16
Dependent Claim
18 words
The method of claim 12, said abrading step comprising sanding a pair of opposed faces of said body.
Claim 17
Dependent Claim
13 words
The method of claim 12, said thickness being less than about 0.05 millimeters.
Claim 18
Dependent Claim
46 words
The method of claim 12, said body being selected from the group consisting of nat LiF, 7 LiF, 6 LiF, Li 2 B 4 O 7 , CaSO 4 , CaF 2 , MgB 4 O 7 , doped species of the foregoing, and mixtures thereof.
Claim 19
Dependent Claim
22 words
The method of claim 12, said body, after said abrading step, having a volume of at least about 0.0125 mm 3 .
Claim 20
Dependent Claim
23 words
The method of claim 12, said body, after said abrading step, having length and width dimensions of at least about 0.5 millimeters respectively.
Claim 21
Dependent Claim
16 words
The method of claim 12, including the step of attaching said abraded body to a block.
Claim 22
Dependent Claim
17 words
The method of claim 19, said attaching step comprising adhesively securing said abraded body to said block.
Claim 23
Dependent Claim
12 words
The method of claim 19, said block being approximately tissue equivalent material.
Claim 24
Dependent Claim
10 words
The method of claim 19, said block being non-tissue equivalent.
Claim 25
Dependent Claim
12 words
The method of claim 12, said body being substantially pure thermoluminescent material.
Claim 26
Dependent Claim
48 words
A radiation dosimeter produced by the method which comprises the steps of: providing a solid, self-sustaining body of thermoluminescent material having a substantially constant density; and physically abrading at least one surface of said body in order to reduce the thickness thereof to less than about 0.15 millimeters.
Claim 27
Dependent Claim
48 words
A radiation dosimeter produced by the method which comprises the steps of: providing a solid, self-sustaining body of thermoluminescent material having a substantially constant density; and physically abrading at least one surface of said body in order to reduce the thickness thereof to less than about 0.15 millimeters.
Claim 28
Independent Claim
61 words
A method of treating a solid thermoluminescent body comprising a crystalline ionic salt of the alkali metal and alkaline earth metals, said method comprising the step of physically abrading a surface of said body to an extent that the body exhibits at least about a factor of two reduction in non-radiation induced thermoluminescence, as compared with an otherwise identical, unabraded body.
Claim 29
Independent Claim
61 words
A method of treating a solid thermoluminescent body comprising a crystalline ionic salt of the alkali metal and alkaline earth metals, said method comprising the step of physically abrading a surface of said body to an extent that the body exhibits at least about a factor of two reduction in non-radiation induced thermoluminescence, as compared with an otherwise identical, unabraded body.
Claim 30
Dependent Claim
15 words
The method of claim 23, said abrading step comprising sanding said surface of said body.
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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) | 1990-01-12 | 1990-07-14 | 1991-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-12 | 1994-07-14 | 1995-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-12 | 1998-07-14 | 1999-01-13 | $7700.00 | Window Closed / Lapsed |