Abstract
A method for obtaining efficient current drive in Tokamaks using low-phase-velocity (v{sub {rho}} = {omega}/K{sub parallel} {proportional_to} 0.1v{sub te}) kinetic Alfen wave is proposed. The wave momentum, imparted primarily to the trapped electrons by Landau damping, is stored as the canonical angular momentum via the Ware pinch. In steady state, collisions restore the pinched electrons to their original phase-space configuration, in the process releasing the stored canonical angular momentum to the background ions and electrons in proportion to the respective collision frequencies. Despite the loss of a part of the original impulse to the plasma ions, well over half the wave momentum is ultimately delivered to the bulk-plasma electrons, resulting in an efficient current drive. A normalized current-drive efficiency {gamma} = R{sub 0} < n{sub 20} > I/P {proportional_to} 2 would be feasible using the subthermal kinetic-Alfen-wave current drive in a Tokamak of reactor parameters. Optimum antenna loading conditions are described. The problem of accessibility is discussed. In an elongated, high-{beta} plasma with a density dependence n{sub e} {proportional_to} (1-{rho}{sup 2}){sup {Chi}n}, accessibility is restricted to {rho} > or approx. 3/(4A{sub {Chi}n}), where A is the aspect ratio. For current drive at still lower values of {rho}, operation in conjunction
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Citation Formats
Puri, S.
High-efficiency toroidal current drive using low-phase-velocity kinetic Alfven waves.
Germany: N. p.,
1991.
Web.
Puri, S.
High-efficiency toroidal current drive using low-phase-velocity kinetic Alfven waves.
Germany.
Puri, S.
1991.
"High-efficiency toroidal current drive using low-phase-velocity kinetic Alfven waves."
Germany.
@misc{etde_10121882,
title = {High-efficiency toroidal current drive using low-phase-velocity kinetic Alfven waves}
author = {Puri, S}
abstractNote = {A method for obtaining efficient current drive in Tokamaks using low-phase-velocity (v{sub {rho}} = {omega}/K{sub parallel} {proportional_to} 0.1v{sub te}) kinetic Alfen wave is proposed. The wave momentum, imparted primarily to the trapped electrons by Landau damping, is stored as the canonical angular momentum via the Ware pinch. In steady state, collisions restore the pinched electrons to their original phase-space configuration, in the process releasing the stored canonical angular momentum to the background ions and electrons in proportion to the respective collision frequencies. Despite the loss of a part of the original impulse to the plasma ions, well over half the wave momentum is ultimately delivered to the bulk-plasma electrons, resulting in an efficient current drive. A normalized current-drive efficiency {gamma} = R{sub 0} < n{sub 20} > I/P {proportional_to} 2 would be feasible using the subthermal kinetic-Alfen-wave current drive in a Tokamak of reactor parameters. Optimum antenna loading conditions are described. The problem of accessibility is discussed. In an elongated, high-{beta} plasma with a density dependence n{sub e} {proportional_to} (1-{rho}{sup 2}){sup {Chi}n}, accessibility is restricted to {rho} > or approx. 3/(4A{sub {Chi}n}), where A is the aspect ratio. For current drive at still lower values of {rho}, operation in conjunction with fast-wave current drive is suggested. (orig.).}
place = {Germany}
year = {1991}
month = {Sep}
}
title = {High-efficiency toroidal current drive using low-phase-velocity kinetic Alfven waves}
author = {Puri, S}
abstractNote = {A method for obtaining efficient current drive in Tokamaks using low-phase-velocity (v{sub {rho}} = {omega}/K{sub parallel} {proportional_to} 0.1v{sub te}) kinetic Alfen wave is proposed. The wave momentum, imparted primarily to the trapped electrons by Landau damping, is stored as the canonical angular momentum via the Ware pinch. In steady state, collisions restore the pinched electrons to their original phase-space configuration, in the process releasing the stored canonical angular momentum to the background ions and electrons in proportion to the respective collision frequencies. Despite the loss of a part of the original impulse to the plasma ions, well over half the wave momentum is ultimately delivered to the bulk-plasma electrons, resulting in an efficient current drive. A normalized current-drive efficiency {gamma} = R{sub 0} < n{sub 20} > I/P {proportional_to} 2 would be feasible using the subthermal kinetic-Alfen-wave current drive in a Tokamak of reactor parameters. Optimum antenna loading conditions are described. The problem of accessibility is discussed. In an elongated, high-{beta} plasma with a density dependence n{sub e} {proportional_to} (1-{rho}{sup 2}){sup {Chi}n}, accessibility is restricted to {rho} > or approx. 3/(4A{sub {Chi}n}), where A is the aspect ratio. For current drive at still lower values of {rho}, operation in conjunction with fast-wave current drive is suggested. (orig.).}
place = {Germany}
year = {1991}
month = {Sep}
}