US3603791A
Expired / Lapsed
US
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Method and device for reading thermoluminescent dosimeters
Assignee: Commissariat à l'Énergie Atomique et Aux Énergies Alternatives
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Filing: 1969-04-07
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Granted: 1971-09-07
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Expires: 1989-04-07
Abstract
Abstract Thermoluminescent dosimeters (e.g., Lif, CaF2) are heated from the variable initial temperature of a dosimeter reader to a predetermined temperature which is higher than the range of emission of peaks which are subject to ''''fading'''' for the emission of such peaks to be complete. Immediately after that step, the temperature of the dosimeter is progressively increased to a temperature which is sufficient to cause the emission of all significant peaks and the total light emission of the dosimeter during said temperature rise is then measured. A reader including a temperature regulation circuit is described which automatically carries out the above sequence.
Inventors
- 👤 Roger Chenault
- 👤 Guy Portal
- 👤 Emile Porrot
- 👤 Raymond Prigent
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:18
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/02; G01T1/10; G01T1/11; G01T1/115
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
41 words
A method in accordance with claim 1 for reading lithium fluoride dosimeters wherein the first temperature is on the order of 130* C. and i is maintained for several seconds and the second temperature is on the order of 250* C.
Claim 2
Dependent Claim
33 words
A method in accordance with claim 1 for reading doped lithium borate dosimeters wherein the first temperature is on the order of 90* C. and is maintained for a period of several seconds.
Claim 3
Dependent Claim
35 words
A method in accordance with claim 1 for reading delta -phase alumina dosimeters wherein the first temperature is on the order of 180* C. and is maintained for a period of at least 15 seconds.
Claim 4
Independent Claim
113 words
A device for reading thermoluminescent dosimeters, comprising a plate receiving the dosimeter a heating resistor for said plate supplied from an alternating-current system through a thyristor, a circuit for controlling said thyristor comprising a unijunction transistor supplied with rectified current from said system a resistor-capacitor circuit for said transistor including a thermistor responsive to the temperature of said plate which limits the power supplied to said heating resistor to a value corresponding to the maintenance of a predetermined temperature and contains at least one element insertable in parallel with resistors connectable in the circuit to cause a rise of the temperature of said plate sufficient to cause the emission of all significant peaks.
Claim 5
Dependent Claim
40 words
A device in accordance with claim 5, wherein said resistor-capacitor circuit comprises a fixed capacitor and two variable resistors mounted in series and in shunt across said capacitor, said thermistor being placed in parallel with one of said variable resistors.
Claim 6
Dependent Claim
44 words
A device in accordance with claim 5, wherein said insertable element consists of a variable resistor inserted in parallel with a fixed resistor interposed between the emitter of said unijunction transistor and the positive pole of said rectified current to cause a temperature rise.
Claim 7
Dependent Claim
58 words
A device in accordance with claim 7, including two time-delay circuits, one of said circuits actuating a relay for putting said variable resistor in circuit at the end of a predetermined time interval corresponding to the preheating time, the other of said circuits maiNtaining said resistor in circuit for a time interval which corresponds to the reading time.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-06 | 1975-03-08 | 1975-09-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-06 | 1979-03-08 | 1979-09-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-06 | 1983-03-08 | 1983-09-07 | $7700.00 | Window Closed / Lapsed |