Patent US4658141A successfully refreshed from Google Patents.
US4658141A
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Inorganic scintillator crystal having a highly reflective surface
Assignee: HARSHAW/FILTROL PARTNERSHIP CLEVELAND OH A PARTNERSHIP OF DE
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Filing: 1984-04-03
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Granted: 1987-04-14
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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 successive coatings of particulate materials such as barium sulfate and titanium dioxide 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
- 👤 Michael C. Wilt
- 👤 Bradley K. Utts
- 👤 Michael L. Toth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:00
CPC Classifications
G; G01; G01T; G01T1/00; G01T1/16; G01T1/20; G01T1/2002
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
124 words
An inorganic scintIllation crystal selected from the group consisting of inorganic halides and inorganic oxides, said crystal having one surface optically coupled to a photodetector, and the remaining surfaces coated with a reflective layer, said layer having a thickness in the range of between about 3 and about 10 mils and adapted to internally reflect scintillation events being emitted by the crystal in the light range of 200-700 nanometers, said reflective layer comprising a coating of a first reflective material in contact with the crystal surface and selected from the group consisting of barium sulfate, aluminum oxide and magnesium oxide and a coating of a second reflective material consisting of titanium dioxide bonded to the first reflective coating by use of a compatible binder.
Claim 2
Dependent Claim
124 words
An inorganic scintIllation crystal selected from the group consisting of inorganic halides and inorganic oxides, said crystal having one surface optically coupled to a photodetector, and the remaining surfaces coated with a reflective layer, said layer having a thickness in the range of between about 3 and about 10 mils and adapted to internally reflect scintillation events being emitted by the crystal in the light range of 200-700 nanometers, said reflective layer comprising a coating of a first reflective material in contact with the crystal surface and selected from the group consisting of barium sulfate, aluminum oxide and magnesium oxide and a coating of a second reflective material consisting of titanium dioxide bonded to the first reflective coating by use of a compatible binder.
Claim 3
Dependent Claim
12 words
The scintillator of claim 1 wherein the compatible binder is sodium silicate.
Claim 4
Dependent Claim
13 words
The scintillator of claim 1 wherein the compatible binder is an acrylic resin.
Claim 5
Dependent Claim
25 words
The crystal of claim 1 wherein the iroganic 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 1 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
83 words
A process of providing a highly reflective layer of inorganic particles on the surface of an inorganic scintillation crystal selected from the group consisting of inorganic halides and inorganic oxides, comprising covering the crystal surface with one or two coatings of a first reflective material comprising barium sulfate, applying over the barium sulfate a second reflective material comprising titanium dioxide and a binder and drying each coating after application, the combined thickness of the coatings being between about 3 and about 10 mils.
Claim 8
Dependent Claim
83 words
A process of providing a highly reflective layer of inorganic particles on the surface of an inorganic scintillation crystal selected from the group consisting of inorganic halides and inorganic oxides, comprising covering the crystal surface with one or two coatings of a first reflective material comprising barium sulfate, applying over the barium sulfate a second reflective material comprising titanium dioxide and a binder and drying each coating after application, the combined thickness of the coatings being between about 3 and about 10 mils.
Claim 9
Dependent Claim
15 words
The process of claim 6 wherein the coatings are applied to the surface by spraying.
Claim 10
Dependent Claim
21 words
The process of claim 6 wherein each coating is deposited to a thickness of between about 1 and about 3 mils.
Claim 11
Dependent Claim
17 words
The process of claim 6 wherein the second material is sprayed on the surface with a binder.
Claim 12
Dependent Claim
11 words
The process of claim 9 wherein the binder is sodium silicate.
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) | 1990-04-13 | 1990-10-13 | 1991-04-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-13 | 1994-10-13 | 1995-04-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-13 | 1998-10-13 | 1999-04-14 | $7700.00 | Window Closed / Lapsed |