US5660627A
Expired / Lapsed
US
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Method of growing lutetium oxyorthosilicate crystals
Assignee: Schlumberger Technology Corp
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Filing: 1994-10-27
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Granted: 1997-08-26
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Expires: 2014-10-27
Abstract
Abstract A method for producing lutetium oxyorthosilicate crystals includes maintaining the interface between a crystal and the melt from which it is pulled substantially flat as the crystal is grown. In a Czochralski growth method, the rate of rotation of the crystal and its diameter are typically controllable to provide the flat interface as the crystal is pulled. Crystals produced by this method exhibit less variability in scintillation behavior so making them particularly suitable for spectroscopic uses. Such crystals find uses in borehole logging tools.
Inventors
- 👤 Ralph A. Manente
- 👤 Frank Bruni
- 👤 Charles L. Melcher
- 👤 Carl A. Peterson
- 👤 Jeffrey S. Schweitzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:17
CPC Classifications
G; G01; G01V; G01V5/00; G01V5/04; C; C30; C30B; C30B15/00; C30B29/00; C30B29/10; C30B29/34
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
33 words
A method of growing lutetium oxyorthosilicate crystals comprising forming a melt of lutetium oxyorthosilicate and drawing a crystal therefrom while maintaining an interface between the crystal and the melt which is substantially flat.
Claim 2
Independent Claim
33 words
A method of growing lutetium oxyorthosilicate crystals comprising forming a melt of lutetium oxyorthosilicate and drawing a crystal therefrom while maintaining an interface between the crystal and the melt which is substantially flat.
Claim 3
Dependent Claim
14 words
A method as claimed in claim 1, which comprises a Czochralski crystal growth method.
Claim 4
Dependent Claim
29 words
A method as claimed in claim 1, wherein the lutetium oxyorthosilicate melt has the formula Ce 2x Lu 2 (1-x) SiO 5 , wherein 2×10 -4 <x<6×10 -2 .
Claim 5
Independent Claim
42 words
A method of producing scintillator crystals comprising forming a melt of lutetium oxyorthosilicate, drawing a lutetium oxyorthosilicate boule therefrom while maintaining an interface between the boule and the melt which is substantially flat, and subdividing the boule to form individual scintillator crystals.
Claim 6
Independent Claim
42 words
A method of producing scintillator crystals comprising forming a melt of lutetium oxyorthosilicate, drawing a lutetium oxyorthosilicate boule therefrom while maintaining an interface between the boule and the melt which is substantially flat, and subdividing the boule to form individual scintillator crystals.
Claim 7
Dependent Claim
14 words
A method as claimed in claim 4, which comprises a Czochralski crystal growth method.
Claim 8
Dependent Claim
29 words
A method as claimed in claim 4, wherein the lutetium oxyorthosilicate melt has the formula Ce 2x Lu 2 (1-x) SiO 5 , wherein 2×10 -4 <x<6×10 -2 .
Claim 9
Dependent Claim
54 words
A Czochralski crystal growth method for producing lutetium oxyorthosilicate crystals comprising forming a melt of lutetium oxyorthosilicate and drawing a crystal therefrom while rotating the crystal and controlling the rate of rotation and the diameter of the crystal so as to maintain an interface between the crystal and the melt which is substantially flat.
Claim 10
Dependent Claim
54 words
A Czochralski crystal growth method for producing lutetium oxyorthosilicate crystals comprising forming a melt of lutetium oxyorthosilicate and drawing a crystal therefrom while rotating the crystal and controlling the rate of rotation and the diameter of the crystal so as to maintain an interface between the crystal and the melt which is substantially flat.
Claim 11
Dependent Claim
22 words
A method as claimed in claim 8, wherein the lutetium oxyorthosilicate crystal comprises a boule from which individual scintillator crystal are formed.
Claim 12
Dependent Claim
29 words
A method as claimed in claim 8, wherein the lutetium oxyorthosilicate melt has the formula Ce 2x Lu 2 (1-x) SiO 5 , wherein 2×10 -4 <x<6×10 -2 .
Claim 13
Dependent Claim
33 words
Lutetium oxyorthosilicate when produced by a method comprising forming a melt of lutetium oxyorthosilicate and drawing a crystal therefrom while maintaining an interface between the crystal and the melt which is substantially flat.
Claim 14
Dependent Claim
33 words
Lutetium oxyorthosilicate when produced by a method comprising forming a melt of lutetium oxyorthosilicate and drawing a crystal therefrom while maintaining an interface between the crystal and the melt which is substantially flat.
Claim 15
Dependent Claim
27 words
Lutetium oxyorthosilicate as claimed in claim 10, wherein the melt has the formula Ce 2x Lu 2 (1-x) SiO 5 , wherein 2×10 -4 <x<6×10 -2 .
Claim 16
Dependent Claim
15 words
Lutetium oxyorthosilicate as claimed in claim 10 when produced by a Czochralski crystal growth technique.
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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) | 2000-08-25 | 2001-02-24 | 2001-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-08-25 | 2005-02-24 | 2005-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-08-25 | 2009-02-24 | 2009-08-26 | $7700.00 | Window Closed / Lapsed |