US4882121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for the detection of E. G. explosive substances
Assignee: Commissariat à l'Énergie Atomique et Aux Énergies Alternatives
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Filing: 1988-03-31
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Granted: 1989-11-21
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Expires: 2008-03-31
Abstract
Abstract It comprises e.g. a 14 MeV neutron generator for supplying these neutrons to an object liable to contain an explosive, a germanium detector and analysis means coupled to the detector and able to analyse the fast γ photons emitted by the object and trapped by the detector and determine the nitrogen/oxygen ratio in the object, so that this ratio can be compared with that of the explosive and establish whether the object contains said explosive.
Inventors
- 👤 Gerard Grenier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:29
CPC Classifications
G; G01; G01T; G01T3/00; G01T3/08; G01V; G01V5/00; G01V5/20; G01V5/22; G01V5/234
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
110 words
A process for detecting an explosive which may be contained in an object, wherein it comprises irradiating the object by means of fast neutron pulses, said fast neutrons having an energy between 7 and 14 MeV, and detecting prompt gamma photons emitted in coincidence with said neutron pulses and having an energy of 5.106 MeV characterizing nitrogen, and prompt gamma photons emitted in coincidence with said neutron pulses and having an energy of 6.130 MeV characterizing oxygen, determining the relative atomic percentage of nitrogen and oxygen in the object by means of the detected 5.106 MeV and 6.130 MeV photons, and comparing said percentage to N/O ratios of known explosives.
Claim 2
Dependent Claim
110 words
A process for detecting an explosive which may be contained in an object, wherein it comprises irradiating the object by means of fast neutron pulses, said fast neutrons having an energy between 7 and 14 MeV, and detecting prompt gamma photons emitted in coincidence with said neutron pulses and having an energy of 5.106 MeV characterizing nitrogen, and prompt gamma photons emitted in coincidence with said neutron pulses and having an energy of 6.130 MeV characterizing oxygen, determining the relative atomic percentage of nitrogen and oxygen in the object by means of the detected 5.106 MeV and 6.130 MeV photons, and comparing said percentage to N/O ratios of known explosives.
Claim 3
Dependent Claim
24 words
A process according to claim 1, wherein said prompt gamma photons are detected by means of a gamma spectrometry chain incorporating a germanium detector.
Claim 4
Dependent Claim
16 words
A process according to claim 1, wherein said pulsed neutrons have an energy of 14 MeV.
Claim 5
Dependent Claim
25 words
A process according to claim 1, wherein said prompt gamma photons are detected by means of a gamma spectrometry chain incorporating an intrinsic germanium detector.
Claim 6
Dependent Claim
60 words
A process according to claim 1, wherein said pulsed neutrons are produced by a pulsed neutron generator and wherein said prompt gamma photons are detected by means of a gamma spectrometry chain incorporating a gamma photon detector which is separated from the neutron generator by a shield which protects the detector from the neutrons and widens away from the generator.
Claim 7
Dependent Claim
32 words
A process according to claim 1, wherein said prompt gamma photons are detected by means of a gamma spectrometry chain incorporating a gamma photon detector provided with means for cooling said detector.
Claim 8
Dependent Claim
27 words
A process according to claim 1, wherein it further comprises detecting capture gamma photons liable to be emitted by the object under the impact of the neutrons.
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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) | 1992-11-20 | 1993-05-22 | 1993-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-20 | 1997-05-22 | 1997-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-20 | 2001-05-22 | 2001-11-21 | $7700.00 | Window Closed / Lapsed |