US4121106A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shielded regenerative neutron detector
Assignee: General Electric Co
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Filing: 1977-02-08
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Granted: 1978-10-17
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Expires: 1997-02-08
Abstract
Abstract An ion chamber type neutron detector is disclosed which has a greatly extended lifespan. The detector includes a fission chamber containing a mixture of active and breeding material and a neutron shielding material. The breeding and shielding materials are selected to have similar or substantially matching neutron capture cross-sections so that their individual effects on increased detector life are mutually enhanced.
Inventors
- 👤 James H. Terhune
- 👤 John P. Neissel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:02
CPC Classifications
H; H01; H01J; H01J47/00; H01J47/12
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
103 words
A neutron detector comprising: a sealed chamber having two spaced electrodes positioned therein; an ionizable gas disposed within the space between said electrodes; a layer of a mixture of an active material and a breeding material positioned within said chamber, said active material and said breeding material being U-235 and U-234, respectively; and a portion of said detector being formed of a shielding material positioned to decrease the neutron flux to which the active material and the breeding material are subjected, said breeding and shielding materials having substantially matching neutron capture cross-section curves, whereby their individual effects on detector life are mutually enhanced.
Claim 2
Dependent Claim
103 words
A neutron detector comprising: a sealed chamber having two spaced electrodes positioned therein; an ionizable gas disposed within the space between said electrodes; a layer of a mixture of an active material and a breeding material positioned within said chamber, said active material and said breeding material being U-235 and U-234, respectively; and a portion of said detector being formed of a shielding material positioned to decrease the neutron flux to which the active material and the breeding material are subjected, said breeding and shielding materials having substantially matching neutron capture cross-section curves, whereby their individual effects on detector life are mutually enhanced.
Claim 3
Dependent Claim
34 words
The neutron detector of claim 1, wherein said mixture of an active and a breeding material is comprised of a ratio ranging from 70:30 to 90:10 of a mixture of U-234 and U-235, respectively.
Claim 4
Dependent Claim
26 words
The neutron detector of claim 2, wherein said mixture of an active material and a breeding material comprises a 80:20 mixture of U-234 and U-235, respectively.
Claim 5
Dependent Claim
26 words
The neutron detector of claim 1, wherein said shielding material has a high neutron capture cross-section at 0.0253 eV and a resonance peak near 5.19 eV.
Claim 6
Dependent Claim
30 words
The neutron detector of claim 1, wherein said shielding material is a material selected from the group consisting of iridium, dysprosium, erbium, thulium, hafnium, boron, silver, gold, lutetium, and uranium-234.
Claim 7
Dependent Claim
37 words
The neutron detector of claim 1, wherein said shielding material is a mixture of two or more of the materials selected from the group consisting of iridium, dysprosium, erbium, thulium, hafnium, boron, silver, gold, lutelium, and uranium-234.
Claim 8
Dependent Claim
22 words
The neutron detector of claim 1, wherein said shielding material is a material selected from the group consisting of iridium and hafnium.
Claim 9
Dependent Claim
12 words
The neutron detector of claim 1, wherein said shielding material is hafnium.
Claim 10
Dependent Claim
15 words
The neutron detector of claim 1, wherein said chamber is made of a shielding material.
Claim 11
Dependent Claim
30 words
The neutron detector of claim 1, wherein said chamber further includes an active length and a sleeve made of a shielding material extending beyond the active length of said chamber.
Claim 12
Dependent Claim
17 words
The neutron detector of claim 1, wherein one of said electrodes is made of a shielding material.
Claim 13
Dependent Claim
25 words
The neutron detector of claim 1, wherein one of said electrodes includes a layer of said mixture of an active material and a breeding material.
Claim 14
Dependent Claim
25 words
The neutron detector of claim 1, wherein each of said electrodes includes a layer of said mixture of an active material and a breeding material.
Claim 15
Dependent Claim
17 words
The neutron detector of claim 1, wherein both of said electrodes are made of a shielding material.
References Cited (Backward Citations)
US3385988A
Cited
US3860845A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-10-16 | 1982-04-17 | 1982-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-16 | 1986-04-17 | 1986-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-16 | 1990-04-17 | 1990-10-17 | $7700.00 | Window Closed / Lapsed |