US4891520A
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Radiation detector
Assignee: Hitachi Ltd
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Filing: 1988-09-02
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Granted: 1990-01-02
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Expires: 2008-09-02
Abstract
Abstract A radiation detector containing as a scintillator a combination of two or more single crystals of cerium doped gadolinium silicate having different Ce concentrations, or a single crystal of cerium doped gadolinium silicate having different Ce concentrations therein, is improved in a spatial resolution and a time resolution.
Inventors
- 👤 Hiroyuki Ishibashi
- 👤 Kazushi Shimizu
- 👤 Kenzo Susa
- 👤 Shinzou Kubota
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:09
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/20; G01T1/202; G01T1/161; G01T1/164; G01T1/1641; G01T1/1644
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
72 words
A radiation detector comprising a scintillator and a photodetector for detecting the light from said scintillator, said scintillator comprising a combination of two or more single crystals of cerium doped gadolinium silicate represented by the formula: Gd.sub.2(1-x) Ce.sub.2x SiO.sub.5 (I) wherein x is in the range of 5×10 -4 ≦x≦1×10 -2 , and said single crystals having x values in the formula (I) that differ from each other by 20% or more.
Claim 2
Dependent Claim
72 words
A radiation detector comprising a scintillator and a photodetector for detecting the light from said scintillator, said scintillator comprising a combination of two or more single crystals of cerium doped gadolinium silicate represented by the formula: Gd.sub.2(1-x) Ce.sub.2x SiO.sub.5 (I) wherein x is in the range of 5×10 -4 ≦x≦1×10 -2 , and said single crystals having x values in the formula (I) that differ from each other by 20% or more.
Claim 3
Dependent Claim
30 words
A radiation detector according to claim 1, wherein one single crystal has an x value of 5×10 -3 and another single crystal has an x value of 1.5×10 -3 .
Claim 4
Dependent Claim
32 words
A radiation detector according to claim 1, wherein the scintillator further comprises one or more single crystals having a luminescence decay time of 60 ns or less, or longer than 220 ns.
Claim 5
Dependent Claim
27 words
A radiation detector according to claim 3, wherein the single crystal showing a luminescence decay time of 60 ns or less is CsF or BaF 2 .
Claim 6
Dependent Claim
41 words
A radiation detector according to claim 3, wherein the single crystal showing a luminescence decay time of longer than 220 ns is CsI:Tl, Bi 4 Ge 3 O 12 , CdWO 4 , NaI:Tl, KI:Tl, CaWO 4 or ZnWO 4 .
Claim 7
Dependent Claim
63 words
A radiation detector comprising a scintillator and a photodetector for detecting light from said scintillator, said scintillator comprising a single crystal of cerium doped gadolinium silicate represented by the formula: Gd.sub.2(1-x) Ce.sub.2x SiO.sub.5 (I) wherein x is in the range of 5×10 -4 ≦x≦1×10 -2 , and said crystal having portions with x values that differ from each other by 20% or more.
Claim 8
Dependent Claim
63 words
A radiation detector comprising a scintillator and a photodetector for detecting light from said scintillator, said scintillator comprising a single crystal of cerium doped gadolinium silicate represented by the formula: Gd.sub.2(1-x) Ce.sub.2x SiO.sub.5 (I) wherein x is in the range of 5×10 -4 ≦x≦1×10 -2 , and said crystal having portions with x values that differ from each other by 20% or more.
Claim 9
Dependent Claim
32 words
A radiation detector according to claim 6, wherein the scintillator further comprises one or more single crystals having a luminescence decay time of 60 ns or less, or longer than 220 ns.
Claim 10
Dependent Claim
27 words
A radiation detector according to claim 12, wherein the single crystal showing a luminescence decay time of 60 ns or less is CsF or BaF 2 .
Claim 11
Dependent Claim
41 words
A radiation detector according to claim 7, wherein the single crystal showing a luminescence decay time of longer than 220 ns is CsI:Tl, Bi 4 Ge 3 O 12 , CdWO 4 , NaI:Tl, KI:Tl, CaWO 4 or ZnWO 4 .
References Cited (Backward Citations)
US4647781A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-01 | 1993-07-03 | 1994-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-01 | 1997-07-03 | 1998-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-01 | 2001-07-03 | 2002-01-02 | $7700.00 | Window Closed / Lapsed |