US3995136A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Enhanced laser beam coupling to a plasma
Assignee: Energy Research and Development Administration ERDA
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Filing: 1974-03-18
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Granted: 1976-11-30
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Expires: 1994-03-18
Abstract
Abstract Density perturbations are induced in a heated plasma by means of a pair of oppositely directed, polarized laser beams of the same frequency. The wavelength of the density perturbations is equal to one half the wavelength of the laser beams. A third laser beam is linearly polarized and directed at the perturbed plasma along a line that is perpendicular to the direction of the two opposed beams. The electric field of the third beam is oriented to lie in the plane containing the three beams. The frequency of the third beam is chosen to cause it to interact resonantly with the plasma density perturbations, thereby efficiently coupling the energy of the third beam to the plasma.
Inventors
- 👤 Arno D. Steiger
- 👤 Cornelius H. Woods
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:06
CPC Classifications
G; G21; G21B; G21B1/00; G21B1/11; G21B1/23; Y; Y02; Y02E; Y02E30/00; Y02E30/10
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
152 words
A method for efficiently coupling the energy of a laser beam to a plasma by anomalous absorption to rapidly and uniformly raise the plasma temperature, indlucing the steps of: creating a warm plasma; directing first and second laser beams of similar polarization and of the same frequency at said plasma, the frequency of said first and second beams being selected to induce a substantial stationary ion density perturbation in said plasma that is one-half the wavelength of the frequency of said laser beams; and directing a third laser beam at said plasma, said third beam being linearly polarized and oriented to have its electric field lying in the plane defined by said three beams to cause interaction between Langmuir waves associated with said induced ion density perturbation and said third beam to thereby effect anomalous absorption of said third beam to thereby effect anomalous absorption of said third beam into said plasma.
Claim 2
Independent Claim
152 words
A method for efficiently coupling the energy of a laser beam to a plasma by anomalous absorption to rapidly and uniformly raise the plasma temperature, indlucing the steps of: creating a warm plasma; directing first and second laser beams of similar polarization and of the same frequency at said plasma, the frequency of said first and second beams being selected to induce a substantial stationary ion density perturbation in said plasma that is one-half the wavelength of the frequency of said laser beams; and directing a third laser beam at said plasma, said third beam being linearly polarized and oriented to have its electric field lying in the plane defined by said three beams to cause interaction between Langmuir waves associated with said induced ion density perturbation and said third beam to thereby effect anomalous absorption of said third beam to thereby effect anomalous absorption of said third beam into said plasma.
Claim 3
Dependent Claim
38 words
The method of claim 1 wherein the intensity of said first and second beams is equal and the intensity of said third laser beam is on the order of 1/10the intensity of said first and second laser beams.
Claim 4
Dependent Claim
46 words
The method of claim 2 wherein the intensity of said first and second beams is on the order of 10 14 to 10 15 W-cm.sup. -2 and the intensity of said third beam is on the order of 10 13 to 10 14 W-cm.sup. -2 .
Claim 5
Dependent Claim
12 words
The method of claim 3 wherein said plasma is derived from deuterium.
Claim 6
Dependent Claim
28 words
The method of claim 1 wherein the step of creating a warm plasma includes the injection of thermonuclear fuel at the point of intersection of said laser beams.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein said first and second lasers are Nyodymium glass lasers and said third laser is a CO 2 laser.
Claim 8
Dependent Claim
39 words
The method of claim 1 wherein the frequency of said first and second laser beams is adjusted to be 1.78 ×10 15 Hz and the frequency of said third laser beam is adjusted to be 1.78 ×10 14 Hz.
Claim 9
Dependent Claim
21 words
The method of claim 1 wherein said first and second beams are linearly polarized and have electric fields that are coplanar.
Claim 10
Dependent Claim
23 words
The method of claim 1 wherein said first and second beams are circularly polarized and have electric fields that are of opposite helicity.
Claim 11
Dependent Claim
28 words
The method of claim 1 wherein said first and second beams are elliptically polarized with congruent ellipses of polarization and have electric fields of opposite senses of rotation.
References Cited (Backward Citations)
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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) | 1979-11-30 | 1980-05-31 | 1980-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-30 | 1984-05-31 | 1984-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-30 | 1988-05-31 | 1988-11-30 | $7700.00 | Window Closed / Lapsed |