Patent US4091288A successfully refreshed from Google Patents.
US4091288A
Expired / Lapsed
US
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Threshold self-powered gamma detector for use as a monitor of power in a nuclear reactor
Assignee: United States Department of Energy
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Filing: 1977-04-04
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Granted: 1978-05-23
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Expires: 1997-04-04
Abstract
Abstract A self-powered gamma monitor for placement near the core of a nuclear reactor comprises a lead prism surrounded by a coaxial thin nickel sheet, the combination forming a collector. A coaxial polyethylene electron barrier encloses the collector and is separated from the nickel sheet by a vacuum region. The electron barrier is enclosed by a coaxial stainless steel emitter which, in turn, is enclosed within a lead casing. When the detector is placed in a flux of gamma rays, a measure of the current flow in an external circuit between emitter and collector provides a measure of the power level of the reactor.
Inventors
- 👤 Francis E. LeVert
- 👤 Samson A. Cox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:01
CPC Classifications
G; G01; G01T; G01T3/00; G01T3/006
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
108 words
A detector of the power level in a nuclear reactor by measuring high-energy gamma rays, the detector comprising: means for screening out low-energy gamma rays; means for generating Compton and photoelectrons in response to high-energy gamma rays; means for screening out low-energy Compton and photoelectrons produced in an emitter; means for screening out low-energy photoelectrons produced by back-scattered gamma rays; means for detecting Compton and photoelectrons produced by the high-energy gamma rays; and means for measuring current of the Compton and photoelectrons produced by high-energy gamma rays, which current is a measure of the flux of high-energy gamma rays and hence of the power level of the reactor.
Claim 2
Dependent Claim
108 words
A detector of the power level in a nuclear reactor by measuring high-energy gamma rays, the detector comprising: means for screening out low-energy gamma rays; means for generating Compton and photoelectrons in response to high-energy gamma rays; means for screening out low-energy Compton and photoelectrons produced in an emitter; means for screening out low-energy photoelectrons produced by back-scattered gamma rays; means for detecting Compton and photoelectrons produced by the high-energy gamma rays; and means for measuring current of the Compton and photoelectrons produced by high-energy gamma rays, which current is a measure of the flux of high-energy gamma rays and hence of the power level of the reactor.
Claim 3
Independent Claim
201 words
An apparatus for measuring power level in a nuclear reactor by detecting gamma rays, the apparatus comprising: a lead prism; a nickel structure enclosing and touching the lead prism coaxially; an insulator supporting the prism and the nickel structure; a vacuum region surrounding the nickel structure coaxially; a coaxial electron barrier surrounding the vacuum region, the electron barrier closed at an end; a coaxial metal emitter surrounding and touching the electron barrier; a coaxial lead shield surrounding and touching the emitter; an end cap at an end of the structure disposed perpendicular to an axis of the structure and connected to the emitter, the electron barrier, and the insulator to maintain relative coaxial positions thereof and form a vacuum seal with the end cap and an electrical connection with the emitter and an electrical ground; an electrical lead connected to the nickel structure and lead prism and extending to the end cap; a coaxial cable having a center conductor connected to the electrical lead and having a shield connected to the end cap; means connected to the vacuum region for establishing and maintaining a vacuum therein; and means connected to the center conductor and electrical ground for measuring electric current therebetween.
Claim 4
Independent Claim
201 words
An apparatus for measuring power level in a nuclear reactor by detecting gamma rays, the apparatus comprising: a lead prism; a nickel structure enclosing and touching the lead prism coaxially; an insulator supporting the prism and the nickel structure; a vacuum region surrounding the nickel structure coaxially; a coaxial electron barrier surrounding the vacuum region, the electron barrier closed at an end; a coaxial metal emitter surrounding and touching the electron barrier; a coaxial lead shield surrounding and touching the emitter; an end cap at an end of the structure disposed perpendicular to an axis of the structure and connected to the emitter, the electron barrier, and the insulator to maintain relative coaxial positions thereof and form a vacuum seal with the end cap and an electrical connection with the emitter and an electrical ground; an electrical lead connected to the nickel structure and lead prism and extending to the end cap; a coaxial cable having a center conductor connected to the electrical lead and having a shield connected to the end cap; means connected to the vacuum region for establishing and maintaining a vacuum therein; and means connected to the center conductor and electrical ground for measuring electric current therebetween.
Claim 5
Dependent Claim
18 words
The apparatus of claim 2 wherein the electron barrier is polyethylene having a nominal thickness of 0.6 cm.
Claim 6
Dependent Claim
18 words
The apparatus of claim 2 wherein the electron barrier is carbon having a nominal thickness of 0.3 cm.
Claim 7
Dependent Claim
19 words
The apparatus of claim 2 wherein the emitter is stainless steel tubing having a nominal thickness of 0.3 cm.
Claim 8
Dependent Claim
21 words
The apparatus of claim 3 wherein the lead prism is a square prism having a cross-section 1.3 cm. on a side.
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) | 1981-05-22 | 1981-11-21 | 1982-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-22 | 1985-11-21 | 1986-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-22 | 1989-11-21 | 1990-05-23 | $7700.00 | Window Closed / Lapsed |