US4631409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scintillator crystal having a highly reflective surface
Assignee: HARSHAW/FILTROL PARTNERSHIP A PARTNERSHIP OF DE
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Filing: 1984-04-03
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Granted: 1986-12-23
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Expires: 2004-04-03
Abstract
Abstract Scintillators, and more particularly inorganic scintillation crystals such as cadmium tungstate, bismuth germanate, barium fluoride and calcium fluoride are coated with one or more coatings of a highly reflective material such as barium sulfate dispersed in a suitable binder such as sodium silicate to provide a highly reflective surface layer capable of providing internal reflection of scintillation events in the region of 200-700 nm. The reflective surface enhances the pulse height and resolution of the scintillator when coupled to a suitable detector such as a photomultiplier tube or a silicon photodiode.
Inventors
- 👤 Frank M. Sparacia
- 👤 Oley D. Wimer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:26
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/20; G01T1/2002
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
76 words
An inorganic scintillation crystal selected from the group consisting of inorganic halides and inorganic oxides wherein the crystal emits light pulses in the 200-700 nm range when the crystal is subjected to ionizing crystal is subjected to ionizing radiation, said crystal having at least one surface coated with a reflective layer capable of reflecting said light pulses back into the crystal, said layer comprising particles of barium sulfate and a binder consisting essentially of sodium silicate.
Claim 2
Dependent Claim
76 words
An inorganic scintillation crystal selected from the group consisting of inorganic halides and inorganic oxides wherein the crystal emits light pulses in the 200-700 nm range when the crystal is subjected to ionizing crystal is subjected to ionizing radiation, said crystal having at least one surface coated with a reflective layer capable of reflecting said light pulses back into the crystal, said layer comprising particles of barium sulfate and a binder consisting essentially of sodium silicate.
Claim 3
Dependent Claim
22 words
The crystal according to claim 1 wherein the sodium silicate comprises between about 6% and 10% by weight of the reflective layer.
Claim 4
Dependent Claim
20 words
The scintillator of claim 1 wherein the surface layer has a thickness of between about 3 and about 20 mils.
Claim 5
Dependent Claim
25 words
The crystal of claim 1 wherein the inorganic halides are selected from the group consisting of BaF 2 , CaF 2 (Eu), CsI(Tl) and TlCl(Be,I).
Claim 6
Dependent Claim
29 words
The crystal of claim 4 wherein the oxides are selected from the group consisting of Bi 4 Ge 3 O 12 , CaWO 4 , and CdWO 4 .
Claim 7
Dependent Claim
37 words
A process of providing a highly reflective layer of barium sulfate particles adhered to the surface of a scintillator comprising coating the surface of the scintillator with the particles dispersed in a binder consisting of sodium silicate.
Claim 8
Dependent Claim
37 words
A process of providing a highly reflective layer of barium sulfate particles adhered to the surface of a scintillator comprising coating the surface of the scintillator with the particles dispersed in a binder consisting of sodium silicate.
Claim 9
Dependent Claim
19 words
The process of claim 6 wherein the particles are deposited on the surface in a plurality of separate applications.
Claim 10
Dependent Claim
12 words
The process of claim 7 including a drying step between each application.
Claim 11
Dependent Claim
15 words
The process of claim 6 wherein the coatings are applied to the surface by spraying.
Claim 12
Dependent Claim
24 words
The process of claim 9 wherein the particles are deposited to a thickness of between about 1 and about 3 mils in each application.
Claim 13
Dependent Claim
59 words
For use in providing a highly reflective layer on the surface of a scintillator, a coating system comprising a dispersion of particles of barium sulfate in a sodium silicate binder wherein the barium sulfate is present in an amount of between 90 and 94 weight percent and the binder is present in an amount of between 6 and 10%.
Claim 14
Dependent Claim
59 words
For use in providing a highly reflective layer on the surface of a scintillator, a coating system comprising a dispersion of particles of barium sulfate in a sodium silicate binder wherein the barium sulfate is present in an amount of between 90 and 94 weight percent and the binder is present in an amount of between 6 and 10%.
Claim 15
Dependent Claim
36 words
The coating system of claim 11 in which up to 10% of the barium sulfate is replaced with particles of a second inorganic reflective material selected from the group consisting of aluminum oxide and magnesium oxide.
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) | 1989-12-22 | 1990-06-23 | 1990-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-22 | 1994-06-23 | 1994-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-22 | 1998-06-23 | 1998-12-23 | $7700.00 | Window Closed / Lapsed |