EP0358237A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Apparatus for and methods of detecting common explosive materials
Assignee: Engility LLC
•
Filing: 1989-09-08
•
Granted: —
•
Expires: 2009-09-08
Abstract
Abstract A beam of energy in a first form, such as electrons, is provided in a first direction. The beam may be pulsed or continuous. The beam is intercepted by a member, such as a converter target (12), to produce energy in a second form such as x-rays. The converter target may be formed from a heavy material such as tungsten or tantalum. The interaction of the electron beam with the converter target will produce energetic bremsstrahlung x-rays in an energy range including 10.6 Mev to approximately 13.0 Mev. This range is sufficient to excite the abundant nitrogen atoms in common explosives to induce the production of annihilation photons but is not sufficient to substantially excite atoms of the most abundant elements of the earth's crust (e.g. oxygen, silicon, iron, aluminum, carbon, hydrogen, etc.), which comprise most common fabricated articles and soils. The converter target is disposed relative to an object (18) (e.g. a suitcase in an airport) to obtain the production of energy in a third form, such as photons, from the object. The photons pass to a detector such as a scintillation counter (20) which determines the concentration of the nitrogen in the object. The detector may be gated so as to be activated only when the photons are passing from the object to the detector. When the object is a suitcase (Fig. 5) which is moved along a conveyor, the detector (66 Fig.5) may be downstream from the source in the direction of movement of the conveyor (64 Fig.5).
Inventors
- 👤 Robert Bruce Miller
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 00:03
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/20; G01N; G01N23/00; G01N23/22; G01N23/221; G01V5/22; G01V5/234
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
103 words
In a combination for determining the presence of explosives by measuring the concentration of nitrogen in an object, means (10, 54; 12, 60) for producing an energy in a first form in a range of energy intensities in which nitrogen, among other elements within and around the object, is preferentially responsive to produce energy in a second form, the means for producing the energy in the first form being disposed to direct energy in the first form to the object and detector means (20, 66) responsive to the energy in the second form for indicating the concentration of the nitrogen in the object.
Claim 2
Dependent Claim
103 words
In a combination for determining the presence of explosives by measuring the concentration of nitrogen in an object, means (10, 54; 12, 60) for producing an energy in a first form in a range of energy intensities in which nitrogen, among other elements within and around the object, is preferentially responsive to produce energy in a second form, the means for producing the energy in the first form being disposed to direct energy in the first form to the object and detector means (20, 66) responsive to the energy in the second form for indicating the concentration of the nitrogen in the object.
Claim 3
Dependent Claim
69 words
In a combination as set forth in claim 1, the means for producing an energy in the first form comprise means (10, 54; 12, 60) for producing x-rays in a particular range of energy greater than that for producing photons from nitrogen atoms but less than that for producing photons from the other elements to obtain the production of photons substantially only from the nitrogen atoms in the object.
Claim 4
Dependent Claim
82 words
In a combination as set forth in claim 2, the means for producing x-rays comprise converter target (12, 60) made from a material having properties of emitting, when bombarded by electrons, x-rays in a particular energy range for obtaining the production of annihilation photons from nitrogen atoms while minimizing the production of annihilation photons from the other elements and means (54) for bombarding the converted target with electrons to obtain the emission of the x-rays from the converted target to the object.
Claim 5
Dependent Claim
25 words
In a combination as set forth in claim 1 or 3, the means for producing the energy in the first form comprise a heavy metal.
Claim 6
Dependent Claim
31 words
In a combination as set forth in one of the claims 1 to 4, the means for producing the energy in the first form comprise a bremsstrahlung converter target (12, 60).
Claim 7
Dependent Claim
55 words
In the combination as set forth in claim 5, the bremsstrahlung converter target (12, 60) producing energy in a range to approximately 13.0 Mev and the nitrogen atoms in the object having a photo nuclear threshold of approximately 10.6 MeV to provide for the production of photons of approximately 0.511 MeV from the nitrogen atoms.
Claim 8
Dependent Claim
38 words
In a combination as set forth in one of the claims 1 to 6, the detector means (20, 66) being disposed relative to the object to detect substantially only the energy from the nitrogen atoms in the object.
Claim 9
Dependent Claim
35 words
In the combination as set forth in one of the claims 1 to 8, means (68) for gating the detector means to respond preferentially to the energy produced from the nitrogen atoms in the object.
Claim 10
Dependent Claim
37 words
In a combination as set forth in claim 8, the means for gating the detector means provide an indication substantially during the time that photons from the nitrogen atoms in the object pass to the detector means.
Claim 11
Dependent Claim
32 words
In a combination as set forth in one of the claims 8 to 9, means (58) for gating the electron bombarding means to obtain the production of the electrons in a pulse.
Claim 12
Dependent Claim
26 words
In a combination as set forth in one of the claims 1 to 10, the other elements comprise elements which are commonly contained in common articles.
Claim 13
Dependent Claim
27 words
In a combination as set forth in one of the claims 1 to 11, the other elements comprise elements which are commonly contained in the earth's crust.
Claim 14
Dependent Claim
23 words
In a combination as set forth in one of the claims 1 to 12, the detector means (20, 66) comprise a scintillation material.
Claim 15
Dependent Claim
21 words
In a combination as set forth in one of the claims 1 to 13, the detector means comprise a scintillation counter.
Claim 16
Independent Claim
101 words
A method for indicating the presence of explosives by measuring the amount of nitrogen in an object, including the steps of: providing a beam of electrons in a first direction, intercepting the electron beam to obtain the production of x-rays in an energy range in which nitrogen is preferentially responsive among other elements within and around the object disposing the object relative to the x-rays to obtain the production of annihilation photons from the nitrogen in the object, and detecting the photons from the nitrogen in the object to provide an indication of the concentration of the nitrogen in the object.
Claim 17
Independent Claim
101 words
A method for indicating the presence of explosives by measuring the amount of nitrogen in an object, including the steps of: providing a beam of electrons in a first direction, intercepting the electron beam to obtain the production of x-rays in an energy range in which nitrogen is preferentially responsive among other elements within and around the object disposing the object relative to the x-rays to obtain the production of annihilation photons from the nitrogen in the object, and detecting the photons from the nitrogen in the object to provide an indication of the concentration of the nitrogen in the object.
Claim 18
Dependent Claim
34 words
A method as set forth in claim 15, the detection of the annihilation photons from the nitrogen is made substantially during the time that the photons are produced from the nitrogen in the object.
Claim 19
Dependent Claim
23 words
A method as set forth in claim 15 or 16, wherein the detection of the photons is made substantially during particular time intervals.
Claim 20
Independent Claim
22 words
A method as set forth in one of the claims 15 to 17 wherein the object is moved relative to the x-rays.
Claim 21
Dependent Claim
32 words
A method as set forth in claim 18, wherein the detection of the photons is downstream in the particular direction from the position at which the x-rays are directed to the object.
References Cited (Backward Citations)
EP0218240A2
Cited
WO1988001788A1
Cited
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.