Patent US4049515A successfully refreshed from Google Patents.
US4049515A
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Laser isotope separation by multiple photon absorption
Assignee: Energy Research and Development Administration ERDA
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Filing: 1975-04-22
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Granted: 1977-09-20
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Expires: 1995-04-22
Abstract
Abstract Multiple photon absorption from an intense beam of infrared laser light may be used to induce selective chemical reactions in molecular species which result in isotope separation or enrichment. The molecular species must have a sufficient density of vibrational states in its vibrational manifold that, in the presence of sufficiently intense infrared laser light tuned to selectively excite only those molecules containing a particular isotope, multiple photon absorption can occur. By this technique, for example, intense CO2 laser light may be used to highly enrich 34S in natural SF6 and 11B in natural BCl3.
Inventors
- 👤 C. Paul Robinson
- 👤 Stephen D. Rockwood
- 👤 Reed J. Jensen
- 👤 John L. Lyman
- 👤 Jack P. Aldridge, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:28
CPC Classifications
B; B01; B01D; B01D59/00; B01D59/34
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
176 words
A method for obtaining elemental values enriched in a particular isotope of said element which comprises a. obtaining a fluid comprising first molecular species containing two or more isotopes of said element, said first molecular species having, in the presence of sufficiently intense laser radiation, a density of vibrational levels sufficient to allow multiple photon absorption to higher vibrational levels from a first lower vibrational level by absorption of photons of the same energy as can excite said first molecular species to said first lower vibrational level; b. irradiating said fluid with infrared laser radiation of a frequency which selectively excites to a first lower vibrational level those molecules of said first molecular species containing a particular isotope of said element, said infrared laser radiation having an intensity sufficient to produce multiple photon absorption from said first lower vibrational level to a plurality of higher vibrational levels thereby producing a vibrational state at which said molecules containing said particular isotope undergo chemical reaction; and c. separating the reaction products of said chemical reaction from said fluid.
Claim 2
Independent Claim
176 words
A method for obtaining elemental values enriched in a particular isotope of said element which comprises a. obtaining a fluid comprising first molecular species containing two or more isotopes of said element, said first molecular species having, in the presence of sufficiently intense laser radiation, a density of vibrational levels sufficient to allow multiple photon absorption to higher vibrational levels from a first lower vibrational level by absorption of photons of the same energy as can excite said first molecular species to said first lower vibrational level; b. irradiating said fluid with infrared laser radiation of a frequency which selectively excites to a first lower vibrational level those molecules of said first molecular species containing a particular isotope of said element, said infrared laser radiation having an intensity sufficient to produce multiple photon absorption from said first lower vibrational level to a plurality of higher vibrational levels thereby producing a vibrational state at which said molecules containing said particular isotope undergo chemical reaction; and c. separating the reaction products of said chemical reaction from said fluid.
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein said fluid is a gas and said first molecular species are polyatomic molecules.
Claim 4
Dependent Claim
14 words
The method of claim 2 wherein said polyatomic molecules contain four or more atoms.
Claim 5
Dependent Claim
49 words
The method of claim 3 wherein said gas contains a second chemical species which does not absorb said laser light and is substantially unreactive with unexcited molecules of said first molecular species but is highly reactive with molecules of said first molecular species excited to an upper vibrational level.
Claim 6
Dependent Claim
11 words
The method of claim 3 wherein said chemical reaction is dissociation.
Claim 7
Dependent Claim
45 words
The method of claim 5 wherein said gas contains a second chemical species which does not absorb said laser radiation and is substantially unreactive with said first molecular species but which is highly reactive with at least one of the reaction products of said dissociation.
Claim 8
Dependent Claim
26 words
The method of claim 6 wherein said gas has a density of which said selectively excited molecules are not substantially deactivated by collision with unexcited molecules.
Claim 9
Dependent Claim
46 words
The method of claim 6 wherein said first molecular species is a volatile halide of an element having two or more isotopes, said volatile halid having spectral features matching or closely coinciding with CO 2 lines, and said infrared laser radiation is CO 2 laser radiation.
Claim 10
Dependent Claim
13 words
The method of claim 8 wherein said volatile halide is admixed with hydrogen.
Claim 11
Dependent Claim
36 words
The method of claim 9 wherein volatile halide is selected from the class consisting of SF 6 , SiF 4 , CH 3 F, BCl 3 , NF 3 , and CF 2 Cl 2 .
Claim 12
Dependent Claim
13 words
The method of claim 10 wherein said volatile halide is SF 6 .
Claim 13
Dependent Claim
30 words
The method of claim 6 wherein said first molecular species is BCl 3 , said infrared laser radiation is CO 2 laser radiation, and said second chemical species is hydrogen.
References Cited (Backward Citations)
US3951768A
Cited
US3937956A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-19 | 1981-03-21 | 1981-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-19 | 1985-03-21 | 1985-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-19 | 1989-03-21 | 1989-09-20 | $7700.00 | Window Closed / Lapsed |