US6093347A
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US
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Rare earth X-ray scintillator compositions
Assignee: General Electric Co
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Filing: 1998-10-28
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Granted: 2000-07-25
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Expires: 2018-10-28
Abstract
Abstract Decay time in scintillator compositions comprising yttrium or lutetium and gadolinium oxides and europium oxide is decreased by incorporating therein at least one of the oxides of ytterbium, samarium, praseodymium, neodymium, dysprosium, holmium, thulium, cerium and erbium as an acceptor. Other properties including afterglow and radiation damage are maintained at acceptable levels.
Inventors
- 👤 Michael John Lynch
- 👤 Steven Jude Duclos
- 👤 Charles David Greskovich
- 👤 Alok Mani Srivastava
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:05
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/50; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7767; C09K11/7783; C09K11/7784; C09K11/7787; G; G01; G01T; G01T1/00; G01T1/16; G01T1/20; G01T1/202; G01T1/2023; G21; G21K; G21K4/00; G21K2004/06
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
87 words
A scintillator composition comprising the following and any reaction products thereof: a major proportion of yttrium oxide or lutetium oxide and a minor proportion of gadolinium oxide as matrix materials, europium oxide in the amount of about 3.1-30 mole percent based on total scintillator composition as an activator producing at least 99% of total emission, a minor decay time-decreasing proportion of an acceptor, and calcium in an amount of about 2-500 mole ppm and cerium in an amount of about 3-500 mole ppm to reduce radiation damage.
Claim 2
Dependent Claim
87 words
A scintillator composition comprising the following and any reaction products thereof: a major proportion of yttrium oxide or lutetium oxide and a minor proportion of gadolinium oxide as matrix materials, europium oxide in the amount of about 3.1-30 mole percent based on total scintillator composition as an activator producing at least 99% of total emission, a minor decay time-decreasing proportion of an acceptor, and calcium in an amount of about 2-500 mole ppm and cerium in an amount of about 3-500 mole ppm to reduce radiation damage.
Claim 3
Dependent Claim
26 words
The scintillator composition of claim 1, comprising calcium in an amount of about 10-150 mole ppm and cerium in an amount of about 10-150 mole ppm.
Claim 4
Dependent Claim
17 words
The scintillator composition of claim 1, comprising europium oxide in the amount of about 3.1-12 mole percent.
Claim 5
Dependent Claim
21 words
A composition according to claim 3 comprising gadolinium oxide in an amount up to about 45 mole percent and yttrium oxide.
Claim 6
Dependent Claim
20 words
A composition according to claim 1, wherein the acceptor is ytterbium oxide in the amount of about 0.02-10.0 mole percent.
Claim 7
Dependent Claim
20 words
A composition according to claim 1 wherein the acceptor is terbium oxide in the amount of about 50-4,000 mole ppm.
Claim 8
Dependent Claim
20 words
A composition according to claim 1, wherein the acceptor is praseodymium oxide in the amount of about 50-4,000 mole ppm.
Claim 9
Dependent Claim
20 words
A composition according to claim 1, wherein the acceptor is holmium oxide in the amount of about 0.01-2.0 mole percent.
Claim 10
Dependent Claim
20 words
A composition according to claim 1, wherein the acceptor is erbium oxide in the amount of about 0.01-2.0 mole percent.
Claim 11
Dependent Claim
20 words
A composition according to claim 1, wherein the acceptor is thulium oxide in the amount of about 0.01-2.0 mole percent.
Claim 12
Dependent Claim
20 words
A composition according to claim 1, wherein the acceptor is samarium oxide in the amount of about 0.01-2.0 mole percent.
Claim 13
Dependent Claim
20 words
A composition according to claim 1, wherein the acceptor is neodymium oxide in the amount of about 0.02-5.0 mole percent.
Claim 14
Dependent Claim
20 words
A composition according to claim 1, wherein the acceptor is dysprosium oxide in the amount of about 0.01-2.0 mole percent.
Claim 15
Independent Claim
124 words
A method for producing an X-ray image comprising the steps of: preparing a scintillator composition comprising the following and any reaction products thereof: a major proportion of yttrium oxide or lutetium oxide and a minor proportion of gadolinium oxide as matrix materials, europium oxide in the amount of about 3.1-30 mole percent based on total scintillator composition as an activator producing at least 99% of total emission, a minor decay time-decreasing proportion of an acceptor, and calcium in an amount of about 2-500 mole ppm and cerium in an amount of about 3-500 mole ppm to reduce radiation damage; and incorporating a scintillator of said composition in an X-ray detector, subjecting said scintillator composition to X-ray radiation and measuring visible emission from said europium.
Claim 16
Independent Claim
124 words
A method for producing an X-ray image comprising the steps of: preparing a scintillator composition comprising the following and any reaction products thereof: a major proportion of yttrium oxide or lutetium oxide and a minor proportion of gadolinium oxide as matrix materials, europium oxide in the amount of about 3.1-30 mole percent based on total scintillator composition as an activator producing at least 99% of total emission, a minor decay time-decreasing proportion of an acceptor, and calcium in an amount of about 2-500 mole ppm and cerium in an amount of about 3-500 mole ppm to reduce radiation damage; and incorporating a scintillator of said composition in an X-ray detector, subjecting said scintillator composition to X-ray radiation and measuring visible emission from said europium.
Claim 17
Dependent Claim
21 words
A method according to claim 14, wherein the scintillator composition comprises europium oxide in the amount of about 3.1-12 mole percent.
Claim 18
Dependent Claim
25 words
A method according to claim 15 wherein said scintillator composition comprises gadolinium oxide in an amount up to about 45 mole percent, and yttrium oxide.
Claim 19
Dependent Claim
20 words
A method according to claim 14, wherein the acceptor is ytterbium oxide in the amount of about 0.02-10.0 mole percent.
Claim 20
Dependent Claim
20 words
A method according to claim 14 wherein the acceptor is terbium oxide in the amount of about 50-4,000 mole ppm.
Claim 21
Dependent Claim
20 words
A method according to claim 14, wherein the acceptor is praseodymium oxide in the amount of about 50-4,000 mole ppm.
Claim 22
Dependent Claim
20 words
A method according to claim 14, wherein the acceptor is holmium oxide in the amount of about 0.01-2.0 mole percent.
Claim 23
Dependent Claim
20 words
A method according to claim 14, wherein the acceptor is erbium oxide in the amount of about 0.01-2.0 mole percent.
Claim 24
Dependent Claim
20 words
A method according to claim 14, wherein the acceptor is thulium oxide in the amount of about 0.01-2.0 mole percent.
Claim 25
Dependent Claim
20 words
A method according to claim 14, wherein the acceptor is samarium oxide in the amount of about 0.01-2.0 mole percent.
Claim 26
Dependent Claim
20 words
A method according to claim 14, wherein the acceptor is neodymium oxide in the amount of about 0.02-5.0 mole percent.
Claim 27
Dependent Claim
20 words
A method according to claim 14, wherein the acceptor is dysprosium oxide in the amount of about 0.01-2.0 mole percent.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-07-25 | 2004-01-24 | 2004-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-07-25 | 2008-01-24 | 2008-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-07-25 | 2012-01-24 | 2012-07-25 | $7700.00 | Window Closed / Lapsed |