US4365155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scintillator with ZnWO4 single crystal
Assignee: Hitachi Ltd
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Filing: 1980-03-20
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Granted: 1982-12-21
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Expires: 2000-03-20
Abstract
Abstract A scintillator formed of a ZnWO4 single crystal having an absorption coefficient less than or equal to 1.8 cm-1 for the light having a wavelength of 520 nm is disclosed which has a luminescence wavelength of 480 nm and therefore can be combined with a photodiode, and which is high in radiation detection sensitivity, short in decay time, and specifically suitable for use in computed tomography.
Inventors
- 👤 Tetsu Oi
- 👤 Kazumasa Takagi
- 👤 Tokuumi Fukazawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:40
CPC Classifications
G; G21; G21K; G21K4/00; C; C09; C09K; C09K11/00; C09K11/08; C09K11/67; C09K11/68; C30; C30B; C30B13/00; C30B15/00; C30B29/00; C30B29/10; C30B29/16; C30B29/22; C30B29/32; G01; G01T; G01T1/00; G01T1/16; G01T1/20; G01T1/202; G01T1/2023; Y; Y10; Y10T; Y10T428/00; Y10T428/31
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
25 words
A scintillator having a zinc-tungstate single crystal as the scintillating material, said zinc-tungstate single crystal having an impurity content of not more than 50 ppm.
Claim 2
Dependent Claim
25 words
A scintillator having a zinc-tungstate single crystal as the scintillating material, said zinc-tungstate single crystal having an impurity content of not more than 50 ppm.
Claim 3
Dependent Claim
21 words
A scintillator according to claim 1, wherein said zinc-tungstate single crystal has an impurity content of not more than 20 ppm.
Claim 4
Dependent Claim
21 words
A scintillator according to claim 1, wherein said zinc-tungstate single crystal has an impurity content of not more than 10 ppm.
Claim 5
Dependent Claim
25 words
A scintillator according to claim 1, wherein a radiation receiving surface of said scintillator and an opposite surface thereto are substantially parallel to each other.
Claim 6
Dependent Claim
24 words
A scintillator according to claim 4, wherein said radiation receiving surface and said opposite surface lie in the (010) plane of said single crystal.
Claim 7
Dependent Claim
31 words
A scintillator according to claim 5, wherein said opposite surface is smoothed to a mirror surface, and each of the remaining surfaces of said scintillator is ground to a rough surface.
Claim 8
Dependent Claim
18 words
A scintillator according to claim 5, wherein said single crystal has a thickness of 2 to 4 mm.
Claim 9
Dependent Claim
102 words
A scintillation counter adapted for counting incident X-rays, comprising: a housing having a window for receiving incident X-rays; a scintillator crystal formed of a zinc tungstate single crystal having an impurity content of not more than 50 ppm and a thickness of 2 to 4 mm and disposed in said housing adjacent to said window for receiving incident X-rays and emitting light rays of a maximum luminescence wavelength of 480 nm; and a photo-detector disposed adjacent to the rear surface of said scintillator crystal in the housing for detecting the light rays emitted from the scintillator crystal, thereby detecting the incident X-rays.
Claim 10
Dependent Claim
102 words
A scintillation counter adapted for counting incident X-rays, comprising: a housing having a window for receiving incident X-rays; a scintillator crystal formed of a zinc tungstate single crystal having an impurity content of not more than 50 ppm and a thickness of 2 to 4 mm and disposed in said housing adjacent to said window for receiving incident X-rays and emitting light rays of a maximum luminescence wavelength of 480 nm; and a photo-detector disposed adjacent to the rear surface of said scintillator crystal in the housing for detecting the light rays emitted from the scintillator crystal, thereby detecting the incident X-rays.
Claim 11
Dependent Claim
19 words
A scintillation counter according to claim 8, wherein said photo-detector includes a silicon photo-diode having a PN junction therein.
Claim 12
Dependent Claim
15 words
A scintillation counter according to claim 9, wherein said photo-detector further includes an amplifier circuit.
Claim 13
Dependent Claim
26 words
A scintillation counter according to claim 8 or 9, wherein said housing includes an aluminum case having the window formed of a portion of reduced thickness.
Claim 14
Dependent Claim
13 words
A scintillation counter according to claim 8, wherein said photo-detector includes a photomultiplier.
Claim 15
Dependent Claim
34 words
A scintillation counter according to claim 8 or 12, wherein the rear surface of said scintillator crystal is coated with silicon grease and brought in close contact with the incident surface of said photo-detector.
Claim 16
Dependent Claim
72 words
In a scintillation counter for use in computed tomography using white X-rays, including a scintillator member for receiving the X-rays and emitting light rays, and a photo-detector for receiving and detecting the light rays emitted from the scintillator member, the improvement comprising: said scintillator member being formed of a single crystal zinc tungstate containing an impurity content of not more than 50 ppm and having a thickness of 2 to 4 mm.
Claim 17
Dependent Claim
72 words
In a scintillation counter for use in computed tomography using white X-rays, including a scintillator member for receiving the X-rays and emitting light rays, and a photo-detector for receiving and detecting the light rays emitted from the scintillator member, the improvement comprising: said scintillator member being formed of a single crystal zinc tungstate containing an impurity content of not more than 50 ppm and having a thickness of 2 to 4 mm.
References Cited (Backward Citations)
US3960756A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-20 | 1986-06-21 | 1986-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-20 | 1990-06-21 | 1990-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-20 | 1994-06-21 | 1994-12-21 | $7700.00 | Window Closed / Lapsed |