Observation of Beam-Induced Currents in a Toroidal Plasma

Start, D.F.H.; Collins, P.R.; Jones, E. M.; Riviere, A.C.; Sweetman, D.R.

doi:10.1103/physrevlett.40.1497

Cited by 25 publications

(10 citation statements)

References 6 publications

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“…The possibility of maintaining a steady-state current in a plasma by the injection of fast ions was first proposed by Ohkawa [1], and recent experiments on the Culham Levitron [2] have confirmed the existence of this current. These measurements revealed a substantial discrepancy between the measured current and the theoretically predicted current.…”

Section: Introductionmentioning

confidence: 96%

“…The original Ohkawa [ 1 ] theory together with other theoretical calculations [2] of this beam-induced current have assumed that the electrons can be represented by a displaced Maxwellian distribution. The displacement is then determined by balancing the rate at which momentum is gained by the electrons from Coulomb collisions with the fast ions against the rate of loss to the thermal ions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A kinetic theory of beam-induced plasma currents

et al. 1979

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A Fokker-Planck treatment of the current induced by a beam of fast ions circulating in a toroidal plasma is developed. The electron Fokker-Planck equation is first reduced to an integro-differential equation which is then solved analytically in the limiting cases of: (a) a large plasma Z and (b) a large ratio of the electron thermal velocity ve to the fast ion velocity vb. In addition, a numerical solution was obtained for the complete range of values of ve/vb and for several values of Z. It is found that the resulting net plasma current has a very different functional dependence upon electron temperature than that given by the conventional theoretical treatment in which the electrons are assumed to be Maxwellian. In particular, for ve > vb and Z = 1, which is the limit appropriate to many present tokamak experiments, the net current is found to be in the opposite direction to the fast-ion current. The theory is compared with recent measurements of this current which were made by using the Culham Levitron, and agreement is found between theory and experiment.

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Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

A kinetic theory of beam-induced plasma currents

et al. 1979

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“…In one such method, suggested by Okhawa [6], the current drive arises from injected fast ions. The first experiment to show the existence of a beam driven current was the Culham superconducting Levitron [7]. The magnitude of the current was very small -approximately 1 A was driven by 10 kW of injected power.…”

Section: Introductionmentioning

confidence: 99%

Non-inductively driven currents in JET

et al. 1989

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Neutral beam heating data from JET have been analysed in detail to determine what proportion of the current is driven non-inductively. It is found that in low density limiter discharges, currents of the order of 0.5 MA are driven, while in H-mode plasmas currents of the order of 0.7 MA are measured. These measured currents are found to be in reasonable agreement with theoretical predictions based on neoclassical models. In low density plasmas the beam driven current is large while the neoclassical bootstrap current dominates H-mode plasmas.

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“…The method of producing current generated by tangential neutral beam injection (NBI) in a tokamak was first proposed by Ohkawa [1], and then the beam-driven current was first observed in the Culham Laboratory Levitron [2]. The toroidal plasma current is indispensable to sustaining plasma equilibrium in a tokamak configuration during discharging.…”

Section: Introductionmentioning

confidence: 98%

The Simulation of Certain Properties of Plasma Affecting Beam-Driven Current in EAST

Wang

et al. 2014

J Fusion Energ

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Some properties of plasma are investigated for the impact of the beam-driven current in experimental advanced superconducting tokamak (EAST). Beam-driven current simulation experiments have been performed to study beam-driven current due to the density, temperature and Z eff of plasma for the on-axis injection. These impact factors for the co-injection and counter-injection are considered qualitatively and quantitatively under some certain specified experimental conditions to guide the future EAST experimental campaign.

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Observation of Beam-Induced Currents in a Toroidal Plasma

Cited by 25 publications

References 6 publications

A kinetic theory of beam-induced plasma currents

A kinetic theory of beam-induced plasma currents

Non-inductively driven currents in JET

The Simulation of Certain Properties of Plasma Affecting Beam-Driven Current in EAST

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