Patent US4020350A successfully refreshed from Google Patents.
US4020350A
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Isotope selective excitation and separation method and apparatus utilizing circularly polarized pulsed radiation
Assignee: Massachusetts Institute of Technology
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Filing: 1975-06-23
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Granted: 1977-04-26
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Expires: 1995-06-23
Abstract
Abstract The isotopes of a gas are separated by using a circularly polarized laser to excite a lower energy level to higher split intermediate energy levels, a second laser pulse of the same circular polarization is applied to said energized gas at a time π/Δω where πΔ is the frequency splitting of the intermediate levels, to excite said excited intermediate levels to a higher energy level where an ionizing field ionizes the atoms or molecules in the higher level so that they may be separated from the un-ionized atoms or molecules of the other isotope.
Inventors
- 👤 Theodore W. Ducas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:12
CPC Classifications
B; B01; B01D; B01D59/00; B01D59/34
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
171 words
A method for selectively populating high-lying excited states of atoms or molecules comprising energizing said atoms or molecules with a first circularly polarized pulsed radiation, the coherent frequency components of said first pulsed radiation have frequencies corresponding to the energy difference between a lower energy level and the frequency split levels of an intermediate energy level, the duration of said pulse being less than 2π/Δω, where Δω is the frequency difference of the splt levels, applying a second circularly polarized pulsed radiation energization to said atoms or molecules for a time subsequent to the termination of said first radiation, the coherent frequency components of said second pulsed radiation have frequencies corresponding to the energy difference between the split levels of said intermediate energy level and an upper energy level, the duration of said second pulse being less than 2π/Δω, the first and second radiation have the same handedness of circular polarization, whereby said upper energy level has a greater population than prior to energization by said first and second radiation pulses.
Claim 2
Independent Claim
171 words
A method for selectively populating high-lying excited states of atoms or molecules comprising energizing said atoms or molecules with a first circularly polarized pulsed radiation, the coherent frequency components of said first pulsed radiation have frequencies corresponding to the energy difference between a lower energy level and the frequency split levels of an intermediate energy level, the duration of said pulse being less than 2π/Δω, where Δω is the frequency difference of the splt levels, applying a second circularly polarized pulsed radiation energization to said atoms or molecules for a time subsequent to the termination of said first radiation, the coherent frequency components of said second pulsed radiation have frequencies corresponding to the energy difference between the split levels of said intermediate energy level and an upper energy level, the duration of said second pulse being less than 2π/Δω, the first and second radiation have the same handedness of circular polarization, whereby said upper energy level has a greater population than prior to energization by said first and second radiation pulses.
Claim 3
Dependent Claim
43 words
The method of claim 1 wherein said first radiation is produced by a laser and said second radiation is produced by the same laser, the second radiation traveling over a longer path than the first radiation to produce a time delayed second radiation.
Claim 4
Dependent Claim
29 words
The method of claim 1 wherein said first pulsed radiation is produced by one laser and said second pulsed radiation is produced by a second laser delayed in time.
Claim 5
Independent Claim
193 words
A method for separating different isotopes of the same atom or molecules comprising energizing said atoms or molecules with a first circularly polarized pulsed radiation, the coherent frequency components of said first pulsed radiation have frequencies corresonding to the energy difference between a lower energy level and the frequency split levels of an intermediate energy level, the duration of said pulse being less than 2π/Δω where Δω is the frequency difference of the split levels, applying a second circularly polarized pulsed radiation energization to said atoms or molecules for a time subsequent to the termination of said first radiation, the coherent frequency components of said second pulsed radiation have frequencies corresponding to the energy difference between the split levels of said intermediate energy level and an upper energy level, the duration of said second pulse being less than 2π/Δω, the first and second radiation have the same handedness of circular polarization, applying an electric field to the energized atoms or molecules subsequent to the second radiation to ionize said high level atoms or molecules, separating said ionizing atoms or molecules of one isotope from the un-ionized atoms or molecules of the other isotope.
Claim 6
Independent Claim
193 words
A method for separating different isotopes of the same atom or molecules comprising energizing said atoms or molecules with a first circularly polarized pulsed radiation, the coherent frequency components of said first pulsed radiation have frequencies corresonding to the energy difference between a lower energy level and the frequency split levels of an intermediate energy level, the duration of said pulse being less than 2π/Δω where Δω is the frequency difference of the split levels, applying a second circularly polarized pulsed radiation energization to said atoms or molecules for a time subsequent to the termination of said first radiation, the coherent frequency components of said second pulsed radiation have frequencies corresponding to the energy difference between the split levels of said intermediate energy level and an upper energy level, the duration of said second pulse being less than 2π/Δω, the first and second radiation have the same handedness of circular polarization, applying an electric field to the energized atoms or molecules subsequent to the second radiation to ionize said high level atoms or molecules, separating said ionizing atoms or molecules of one isotope from the un-ionized atoms or molecules of the other isotope.
Claim 7
Dependent Claim
26 words
The method of claim 1 wherein the time at which the second radiation is applied is approximately π/Δω seconds after said first laser radiation is applied.
Claim 8
Dependent Claim
35 words
The method of claim 1 wherein the duration of the first and second laser pulses and the time interval between them are those values which result in the largest population of the high energy level.
Claim 9
Dependent Claim
172 words
Apparatus for selectively populating high-lying excited states of atoms or molecules comprising means for energizing said atoms or molecules with a first circularly polarized pulsed radiation, the coherent frequency components of said first pulsed radiation have frequencies corresponding to the energy difference between a lower energy level and the frequency split levels of an intermediate energy level, the duration of said pulse being less than 2π/Δω, where Δω is the frequency difference of the split levels, means for applying circularly polarized pulsed radiation energization to said atoms or molecules for a time subsequent to the termination of said first radiation, the coherent frequency components of said second pulsed radiation have frequencies corresponding to the energy difference between the split levels of said intermediate energy level and an upper energy level, the duration of said second pulse being less than 2π/Δω, the first and second radiation have the same handedness of circular polarization, whereby said upper energy level has a greater population than prior to energization by said first and second radiation pulses.
Claim 10
Dependent Claim
172 words
Apparatus for selectively populating high-lying excited states of atoms or molecules comprising means for energizing said atoms or molecules with a first circularly polarized pulsed radiation, the coherent frequency components of said first pulsed radiation have frequencies corresponding to the energy difference between a lower energy level and the frequency split levels of an intermediate energy level, the duration of said pulse being less than 2π/Δω, where Δω is the frequency difference of the split levels, means for applying circularly polarized pulsed radiation energization to said atoms or molecules for a time subsequent to the termination of said first radiation, the coherent frequency components of said second pulsed radiation have frequencies corresponding to the energy difference between the split levels of said intermediate energy level and an upper energy level, the duration of said second pulse being less than 2π/Δω, the first and second radiation have the same handedness of circular polarization, whereby said upper energy level has a greater population than prior to energization by said first and second radiation pulses.
Claim 11
Dependent Claim
43 words
The apparatus of claim 7 wherein said first radiation energizing means is a laser and said second radiation energizing means is the same laser, the second radiation traveling over a longer path than the first radiation to produce a time delayed second radiation.
Claim 12
Dependent Claim
26 words
The apparatus of claim 7 wherein said first pulsed radiation energizing means is one laser and said second pulsed radiation energizing means is a second laser.
Claim 13
Dependent Claim
200 words
Apparatus for separating different isotopes of the same atom or molecule comprising means for energizing said atoms or molecules with a first circularly polarized pulsed radiation, the coherent frequency components of said first pulsed radiation have frequencies corresponding to the energy difference between a lower energy level and the frequency split levels of an intermediate energy level, the duration of said pulse being less than 2π/Δω where Δω is the frequency difference of the split levels, means for applying a second circularly polarized pulsed radiation energization to said atoms or molecules for a time subsequent to the termination of said first radiation, the coherent frequency components of said second pulsed radiation have frequencies corresponding to the energy difference between the split levels of said intermediate energy level and an upper energy level, the duration of said second pulse being less than 2π/Δω, the first and second radiation have the same handedness of circular polarization, means for applying an electric field to the energized atoms or molecules subsequent to the second radiation to ionize said high level atoms or molecules, means for separating said ionized atoms or molecules of one isotope from the un-ionized atoms or molecules of the other isotope.
Claim 14
Dependent Claim
200 words
Apparatus for separating different isotopes of the same atom or molecule comprising means for energizing said atoms or molecules with a first circularly polarized pulsed radiation, the coherent frequency components of said first pulsed radiation have frequencies corresponding to the energy difference between a lower energy level and the frequency split levels of an intermediate energy level, the duration of said pulse being less than 2π/Δω where Δω is the frequency difference of the split levels, means for applying a second circularly polarized pulsed radiation energization to said atoms or molecules for a time subsequent to the termination of said first radiation, the coherent frequency components of said second pulsed radiation have frequencies corresponding to the energy difference between the split levels of said intermediate energy level and an upper energy level, the duration of said second pulse being less than 2π/Δω, the first and second radiation have the same handedness of circular polarization, means for applying an electric field to the energized atoms or molecules subsequent to the second radiation to ionize said high level atoms or molecules, means for separating said ionized atoms or molecules of one isotope from the un-ionized atoms or molecules of the other isotope.
Claim 15
Dependent Claim
26 words
The apparatus of claim 7 wherein the time at which the second radiation is applied is approximately π/Δω seconds after said first laser radiation is applied.
Claim 16
Dependent Claim
35 words
The apparatus of claim 7 wherein the duration of the first and second laser pulses and the time interval between them are those values which result in the largest population of the high energy level.
References Cited (Backward Citations)
US3772519A
Cited
DE2312194A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |