Patent US4240992A successfully refreshed from Google Patents.
US4240992A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Technique for fabricating radiation sensitive dosimeters
Assignee: Northrop Grumman Corp
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Filing: 1978-04-03
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Granted: 1980-12-23
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Expires: 1998-04-03
Abstract
Abstract The finely-divided particles of a selected phosphor material are combined with an aqueous solution of a suitable binder material to form an emulsion which is spread uniformly on the smooth surface of a support member. The wet coating is then heated to remove the water and the resulting film is sintered to produce a strong, continuous film. The film is then peeled from the support member resulting in a uniformly thick sheet of phosphor and binder from which dosimeters can be cut or stamped to any desired size.
Inventors
- 👤 Edward M. Petrie
- 👤 John G. Seidel
- 👤 Patrick E. Felice
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:31
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/02; G01T1/10; G01T1/11; C; C09; C09K; C09K11/00; C09K11/02; C09K11/08; C09K11/77; C09K11/7713; Y; Y10; Y10S; Y10S250/00; Y10S250/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
164 words
A method of fabricating a peelable alpha responsive radiation dosimeter film, comprising the steps of, mixing thermoluminescent radiation sensitive phosphor particles and a binder particle dispersion in water to form an aqueous emulsion of phosphor particles and binder particles in suspension, said aqueous emulsion having a viscosity of 30 centipose or greater, spreading the emulsion onto the surface of a support member to form a uniformly thick emulsion coating, said thickness being such that the removal of water results in a dosimeter coating of a thickness which renders the dosimeter coating responsive to alpha radiation, heating the emulsion coating to remove the water and form a dry dosimeter coating of phosphor particles and binder particles of a thickness which renders the dosimeter coating responsive to alpha radiation, sintering the dry dosimeter coating to form a continuous alpha responsive dosimeter film, said binder being such that said dosimeter film is a peelable dosimeter film, and peeling said alpha responsive dosimeter film from said support member.
Claim 2
Independent Claim
164 words
A method of fabricating a peelable alpha responsive radiation dosimeter film, comprising the steps of, mixing thermoluminescent radiation sensitive phosphor particles and a binder particle dispersion in water to form an aqueous emulsion of phosphor particles and binder particles in suspension, said aqueous emulsion having a viscosity of 30 centipose or greater, spreading the emulsion onto the surface of a support member to form a uniformly thick emulsion coating, said thickness being such that the removal of water results in a dosimeter coating of a thickness which renders the dosimeter coating responsive to alpha radiation, heating the emulsion coating to remove the water and form a dry dosimeter coating of phosphor particles and binder particles of a thickness which renders the dosimeter coating responsive to alpha radiation, sintering the dry dosimeter coating to form a continuous alpha responsive dosimeter film, said binder being such that said dosimeter film is a peelable dosimeter film, and peeling said alpha responsive dosimeter film from said support member.
Claim 3
Dependent Claim
21 words
A method as claimed in claim 1 wherein said radiation sensitive phosphor particles are of a 200 mesh size or finer.
Claim 4
Dependent Claim
22 words
A method as claimed in claim 1 wherein the heating of the emulsion coating is to a temperature of approximately 120° C.
Claim 5
Dependent Claim
28 words
The method as claimed in claim 1 wherein the sintering of the dry coating is achieved by heating the dry coating to a temperature of approximately 370° C.
Claim 6
Dependent Claim
43 words
A method as claimed in claim 1 wherein said binder particle dispersion in water is a aqueous polytetrafluoroethylene dispersion containing a surfactant for maintaining the binder particles in suspension, wherein said sintering step occurs for at least three hours to move said surfactant.
Claim 7
Dependent Claim
32 words
A method as claimed in claim 1 further including the step of cutting or stamping dosimeter elements from said dosimeter film following the peeling of said dosimeter film from said support member.
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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) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |