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US 5,665,971 AGranted
Radiation detection and tomography
AssigneeMassachusetts Institute of Technology
InventorsMin Chen, Alexander I. Bolozdynya
Life of this patent
Estimating the term…
Abstract
A nuclear or x-ray detector which utilizes Compton double-scattering of photons by radiation particles, followed by photoelectron absorption, to reconstruct the energy and direction of such particles.
Claims29
Apparatus for detecting the incoming direction of incident radiation from which the origin of the radiation can be located comprising:
- a) a detection chamber containing a volume of converter molecules, and wherein, upon collision of incident radiation with a molecule at a point X.sub.1 Y.sub.1 Z.sub.1, a photon is produced which scatters at an angle .theta..sub.1, along with a first recoil electron e.sub.1 and initial scintillation light at time t.sub.0, and wherein said photon, in turn, collides with another molecule at a point X.sub.2 Y.sub.2 Z.sub.2, resulting in absorption of said photon and production of a second recoil electron e.sub.2 ;
- b) a first detector array exposed to said volume of molecules for determining t.sub.0 ;
- c) a second detector array exposed to said volume of molecules for detecting the time of arrival, of at least one of said first and second recoil electrons whereby said angle .theta..sub.1 may be calculated and thus the incoming radiation direction;
- and
- d) a processor responsive to said first and second detector arrays for calculating said angle .theta..sub.1.
2 more elements
A method for detecting the incoming direction of incident radiation incident in a medium containing a high Z converter molecule from which the origin of the radiation can be located, comprising the steps of:
- a) converting the radiation into particles by collision of the radiation with a molecule at a point A, resulting in production of a photon which scatters at an angle .theta..sub.1, and a recoil electron e.sub.1 and initial scintillation light at time t.sub.0, and wherein said photon collides with another molecule at a point B, resulting in absorption of said photon and production of a second recoil electron e.sub.2 ;
- b) in a first detector determining t.sub.0 ;
- c) in a second detector detecting the position and time of arrival of at least one of said electrons, whereby said angle .theta..sub.1, may be calculated and thus the direction of the incoming radiation;
- and
- d) calculating the angle .theta..sub.1 and thus the direction of the incoming radiation.
2 more elements
A method of detecting incident nuclear radiation comprising the steps of:
- a) containing converter molecules in a chamber;
- b) contacting said molecules with a photocathode;
- c) colliding said molecules with said radiation a drift region within said chamber formed by a relatively weak electric field to generate electrons and scintillation light from the collision between said incident nuclear radiation and said molecules;
- d) accelerating said electrons in a high electric field gain region formed adjacent said photocathode in which said molecules are in a gaseous state and to cause said electrons to collide with said molecules to produce a plurality of UV photons, many of which impinge on said photocathode to produce a plurality of photoelectrons thereby multiplying the number of photoelectrons detected;
- and
- e) detecting the scintillation light with photomultiplier tubes.
3 more elements
Apparatus for detecting the incoming direction of incident radiation from which the origin of the radiation can be located comprising:
- a) a detection chamber containing a volume of converter molecules, and wherein, upon collision of incident radiation with a molecule at a point X.sub.1 Y.sub.1 Z.sub.1, a photon is produced which scatters at an angle .theta..sub.1, along with a first recoil electron e.sub.1 and initial scintillation light at time t.sub.0, and wherein said photon, in turn, collides with another molecule at a point X.sub.2 Y.sub.2 Z.sub.2, resulting in absorption of said photon and production of a second recoil electron e.sub.2 ;
- b) a first detector array exposed to said volume of molecules for determining t.sub.0 ;
- c) a second detector array exposed to said volume of molecules for detecting the time of arrival, of at least one of said electrons whereby said angle .theta..sub.1 may be calculated and thus the incoming radiation direction;
- d) light guides disposed within said volume of molecules and adjacent said first detector array for enhancing collection of scintillation light;
- and
- e) a processor responsive to said first and second detector arrays for calculating the angle .theta..sub.1.
3 more elements
A method for detecting the incoming direction of incident radiation incident in a medium containing a high Z converter molecule from which the origin of the radiation can be located, comprising the steps of:
- a) converting the radiation into particles by collision of the radiation with a molecule at a point A, resulting in production of a photon which scatters at an angle .theta..sub.1, and a first recoil electron e.sub.1 and initial scintillation light at time t.sub.0, and wherein said photon collides with another molecule at a point B, resulting in absorption of said photon and production of a second recoil electron e.sub.2 ;
- b) in a first detector determining t.sub.0 ;
- c) in a second detector detecting the time of arrival of one of said electrons, whereby said angle .theta..sub.1, may be calculated and thus the direction of the incoming radiation;
- d) shielding the first detector from electroluminescence produced by said electrons;
- and
- e) calculating the direction of the incoming radiation in response to the first and second detector.
3 more elements
A method of detection incident nuclear radiation comprising the steps of:
- a) containing converter molecules in a chamber;
- b) contacting said molecules with a photocathode;
- c) colliding said molecules with said radiation in a drift region within said chamber formed by a relatively weak electric field to generate electrons and scintillation light from the collision between said incident nuclear radiation and said molecules;
- d) accelerating said electrons in a high electric field gain region formed adjacent said photocathode in which said molecules are in a gaseous state and to cause said electrons to collide with said molecules to produce a plurality of UV photons, many of which impinge on said photocathode to produce photoelectrons, thereby multiplying the number of photoelectrons detected;
- e) detecting the scintillation light with photomultiplier tubes;
- and
- f) shielding the photomultiplier tubes from electroluminescence produced by said electrons.
4 more elements
Dependencies are inferred from the claim text.