Patent US4421713A successfully refreshed from Google Patents.
US4421713A
Expired / Lapsed
US
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Tokamak plasma heating with intense, pulsed ion beams
Assignee: United States Department of the Navy
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Filing: 1981-03-25
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Granted: 1983-12-20
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Expires: 2001-03-25
Abstract
Abstract An intense, space-charge-neutralized, pulsed ion beam is used to heat a metically-confined plasma, such as a tokamak plasma, by injecting the ion beam into the plasma along a trajectory that is generally tangential to the confining magnetic field. The ion beam inductively generates a plasma return current so that no net current is produced. As the ion beam drifts in the plasma, the confining magnetic field is transformed into one which can trap the ion beam at the center of the plasma. Once the ion beam is trapped, the plasma return current is cancelled by transformer action to produce a net current which is carried by the ion beam alone. The beam transfers its energy to the plasma by classical collisions with the electrons and ions of the plasma. Heating of the plasma can be sufficient to produce a breakeven condition or ignition.
Inventors
- 👤 Wallace M. Manheimer
- 👤 Niels K. Winsor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:17
CPC Classifications
H; H05; H05H; H05H1/00; H05H1/02; H05H1/22; G; G21; G21B; G21B1/00; G21B1/11; G21B1/15; Y; Y02; Y02E; Y02E30/00; Y02E30/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
135 words
Apparatus for heating a plasma, the plasma being confined in an apparatus of the type wherein the plasma is confined in a vacuum chamber by a magnetic field, and no plasma current is initially carried by the plasma, comprising: means for producing a space-charge-neutralized, pulsed, ion beam; means for directing the ion beam into the plasma-confining chamber, means for transforming the magnetic field to one which can trap the ion beam at the center of the plasma; and means for cancelling a plasma return current inductively generated in the plasma by the ion beam current so that a net current is produced which is carried by the ion beam alone, and which is dissipated by the ion beam's transferring its energy to the plasma by classical collisions with the electrons and ions of the plasma.
Claim 2
Dependent Claim
135 words
Apparatus for heating a plasma, the plasma being confined in an apparatus of the type wherein the plasma is confined in a vacuum chamber by a magnetic field, and no plasma current is initially carried by the plasma, comprising: means for producing a space-charge-neutralized, pulsed, ion beam; means for directing the ion beam into the plasma-confining chamber, means for transforming the magnetic field to one which can trap the ion beam at the center of the plasma; and means for cancelling a plasma return current inductively generated in the plasma by the ion beam current so that a net current is produced which is carried by the ion beam alone, and which is dissipated by the ion beam's transferring its energy to the plasma by classical collisions with the electrons and ions of the plasma.
Claim 3
Dependent Claim
19 words
The apparatus recited in claim 1 wherein: the magnetic field-transforming means transforms the magnetic field to a betatron field.
Claim 4
Dependent Claim
28 words
The apparatus recited in claim 2 wherein the plasma return current-cancelling means includes: primary windings spaced from the plasma-confining chamber for inducing a plasma current by transformer action.
Claim 5
Independent Claim
123 words
A method for heating a plasma initially carrying no plasma current and confined in a magnetic field in a vacuum chamber, comprising the steps of: (a) producing a space-charge-neutralized pulsed ion beam; (b) injecting the beam into the plasma-confining chamber, the ion beam current inductively generating a plasma return current so that no net current is produced; (c) transforming the magnetic field to one which can trap the ion beam at the center of the plasma; and (d) cancelling the plasma return current so that a net current is produced which is carried by the ion beam alone, and which is dissipated by the ion beam's transferring its energy to the plasma via classical collisions with the electrons and ions of the plasma.
Claim 6
Independent Claim
123 words
A method for heating a plasma initially carrying no plasma current and confined in a magnetic field in a vacuum chamber, comprising the steps of: (a) producing a space-charge-neutralized pulsed ion beam; (b) injecting the beam into the plasma-confining chamber, the ion beam current inductively generating a plasma return current so that no net current is produced; (c) transforming the magnetic field to one which can trap the ion beam at the center of the plasma; and (d) cancelling the plasma return current so that a net current is produced which is carried by the ion beam alone, and which is dissipated by the ion beam's transferring its energy to the plasma via classical collisions with the electrons and ions of the plasma.
Claim 7
Dependent Claim
18 words
The method recited in claim 4 where step (d) includes: magnetically linking a primary winding to the plasma.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-19 | 1987-06-20 | 1987-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-19 | 1991-06-20 | 1991-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-19 | 1995-06-20 | 1995-12-20 | $7700.00 | Window Closed / Lapsed |