US3699337A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Personnel neutron dosimeter
Assignee: United States Atomic Energy Commission
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Filing: 1971-03-16
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Granted: 1972-10-17
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Expires: 1991-03-16
Abstract
Abstract A dosimeter is disclosed for measuring the neutron dose equivalent for spectra of widely different energy distributions. A hemispherical mass of neutron moderating material is divided into two segments by a layer of thermal neutron absorbing material. Each segment has a thermal neutron detector at its base surface. Another layer of thermal neutron absorbing material covers the curved surface of the hemispherical mass but has a portion of reduced thickness at the apex. Neutrons passing through and backscattered from the wearer are monitored by one of the neutron detectors while the second detector corrects for directly impinging thermal neutrons that contribute a disproportionately small amount to dose.
Inventors
- 👤 John E Hoy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:22
CPC Classifications
G; G01; G01T; G01T3/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
192 words
In a personnel dosimeter for measuring neutron dose equivalent over a wide neutron energy spectrum wherein said dosimeter includes first and second segments of neutron moderating material, each of said segments having curved and base surfaces, first and second thermal neutron detectors respectively disposed at a base surface of each segment, a layer of thermal neutron absorbing material disposed over the curved surface of each segment and the base surface of one of said segments, and structural means for supporting said dosimeter adjacent to an individual with said curved surfaces projecting outwardly from said individual, the improvement comprising: A. said first and second segments being apex and truncated segments of a single generally hemispherical mass of neutron moderating material; B. said layer of neutron absorbing material having a portion of reduced thickness on the curved surface of said apex segment for admitting thermal neutrons; and C. said structural means including a substantially neutron transparent base plate of inert metal aligned with the base surface of said generally hemispherical mass, said base plate having attachment means adjacent to opposing circumferential portions of said mass for maintaining said base plate firmly against said individual.
Claim 2
Dependent Claim
192 words
In a personnel dosimeter for measuring neutron dose equivalent over a wide neutron energy spectrum wherein said dosimeter includes first and second segments of neutron moderating material, each of said segments having curved and base surfaces, first and second thermal neutron detectors respectively disposed at a base surface of each segment, a layer of thermal neutron absorbing material disposed over the curved surface of each segment and the base surface of one of said segments, and structural means for supporting said dosimeter adjacent to an individual with said curved surfaces projecting outwardly from said individual, the improvement comprising: A. said first and second segments being apex and truncated segments of a single generally hemispherical mass of neutron moderating material; B. said layer of neutron absorbing material having a portion of reduced thickness on the curved surface of said apex segment for admitting thermal neutrons; and C. said structural means including a substantially neutron transparent base plate of inert metal aligned with the base surface of said generally hemispherical mass, said base plate having attachment means adjacent to opposing circumferential portions of said mass for maintaining said base plate firmly against said individual.
Claim 3
Dependent Claim
34 words
The dosimeter of claim 1 wherein said structural means includes a substantially neutron transparent external covering of inert metal over the curved surfaces of said segments outside said layer of thermal neutron absorbing material.
Claim 4
Dependent Claim
22 words
The dosimeter of claim 1 wherein said portion of reduced thickness comprises an opening through said layer of thermal neutron absorbing material.
Claim 5
Dependent Claim
31 words
The dosimeter of claim 1 wherein said attachment means comprises slotted openings through said base plate on opposite sides of said mass for receiving a belt member attached to said individual.
Claim 6
Dependent Claim
16 words
The dosimeter of claim 1 wherein said thermal neutron detectors comprise 6LiF and 7LiF thermoluminescent phosphors.
Claim 7
Dependent Claim
15 words
The dosimeter of claim 1 wherein said layer of thermal neutron absorbing material comprises cadmium.
Claim 8
Dependent Claim
17 words
The dosimeter of claim 1 wherein said apex segment is of smaller mass than said truncated segment.
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) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |