Patent US3854047A successfully refreshed from Google Patents.
US3854047A
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US
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Detector having a plurality of pairs of photo-detectors for determining the coordinates of a light event in a scintillator crystal
Assignee: Elscint Ltd
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Filing: 1972-09-07
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Granted: 1974-12-10
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Expires: 1992-09-07
Abstract
Abstract A detector responsive to incidences of individual radiation stimuli comprises a scintillator crystal defined by a peripheral edge surface whose generatrix is parallel to the central axis of the crystal, and a pair of polished and non-coated parallel faces perpendicular to the axis; and a plurality of photo-detectors each of which has a photo-sensitive surface positioned adjacent to the different segments of the edge surface of the crstal for receiving light emitted by the crystal in response to an event in the crystal caused by a gamma ray. The output of each photodetector is functionally dependent on the planar coordinates of the event relative to the central axis, but is substantially independent of the axial location of the event in the crystal.
Inventors
- 👤 A Suhami
- 👤 B Sabbah
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:32
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/161; G01T1/164; G01T1/1641; G01T1/1642
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
139 words
A detector responsive to incident radiation stimuli comprising: a scintillator crystal responsive to an event therein caused by radiation stimulus for emitting a light pulse; the crystal being defined by a peripheral edge surface whose generatrix is parallel to the central axis of the crystal, and a pair of parallel polished and non-coated faces perpendicular to the axis; and a plurality of pairs of photo-detectors each of which has a photo-sensitive surface positioned adjacent different segments of the edge surface of the crystal for receiving light emitted by the crystal in response to an event, each photo detector of a pair being in diametrical alignment whereby the output of each photodetector is functionally dependent on the planar coordinates of the event relative to the central axis but is independent of the axial location of the event in the crystal.
Claim 2
Dependent Claim
139 words
A detector responsive to incident radiation stimuli comprising: a scintillator crystal responsive to an event therein caused by radiation stimulus for emitting a light pulse; the crystal being defined by a peripheral edge surface whose generatrix is parallel to the central axis of the crystal, and a pair of parallel polished and non-coated faces perpendicular to the axis; and a plurality of pairs of photo-detectors each of which has a photo-sensitive surface positioned adjacent different segments of the edge surface of the crystal for receiving light emitted by the crystal in response to an event, each photo detector of a pair being in diametrical alignment whereby the output of each photodetector is functionally dependent on the planar coordinates of the event relative to the central axis but is independent of the axial location of the event in the crystal.
Claim 3
Dependent Claim
30 words
A detector according to claim 1 wherein the edge surface of the crystal is contoured to mate with the light input face of the photo-detectors adjacent their respective sensitive surfaces.
Claim 4
Dependent Claim
18 words
A detector according to claim 2 wherein the input faces of the photo-detectors are cemented to the crystal.
Claim 5
Dependent Claim
21 words
A detector according to claim 1 in combination with a collimator positioned on one of the parallel faces of the crystal.
Claim 6
Dependent Claim
26 words
A detector according to claim 1 in combination with computing means responsive to the output of the photo-detector for computing the planar coordinates of an event.
Claim 7
Dependent Claim
28 words
A detector according to claim 1, wherein said computing means is effective to compute the polar coordinates of an event relative to the central axis of the crystal.
Claim 8
Dependent Claim
86 words
Apparatus according to claim 6 wherein said computing means includes a pulse stretcher for each photo-detector for prolonging the duration of the output of the photo-detectors in response to a light pulse in the crystal, means for sequentially computing the value of different sets of two groups of photo-detectors by summing the outputs of the groups, and logic means responsive to the value of the sets for identifying either the set having zero value or the first of two consecutive sets whose values change in sign.
Claim 9
Dependent Claim
47 words
Apparatus according to claim 7 including additional logic means for identifying the sign of the next set following a set having zero value or the sign of the second of two consecutive sets whose value change in sign whereby the polar angle of an event is ascertained.
Claim 10
Dependent Claim
42 words
Apparatus according to claim 8 including an adder for summing the outputs of the photo-detectors, an integrator responsive to the contents of the adder for producing a control signal, and a comparator for determining the occurrence of a zero-crossover of the signal.
Claim 11
Dependent Claim
32 words
Apparatus according to claim 8 including means responsive to the output of a set of photo-detectors determined by the polar angle of an event for computing the radial displacement of the event.
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) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |