Scale Size of Magnetic Turbulence in Tokamaks Probed with 30-MeV Electrons
- 17 April 2000
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 84 (16), 3606-3609
- https://doi.org/10.1103/physrevlett.84.3606
Abstract
Measurements of synchrotron radiation emitted by 30-MeV runaway electrons in the TEXTOR-94 tokamak show that the runaway population decays after switching on neutral beam injection (NBI). The decay starts only with a significant delay, which decreases with increasing NBI heating power. This delay provides direct evidence of the energy dependence of runaway confinement, which is expected if magnetic modes govern the loss of runaways. Application of the theory by Mynick and Strachan [Phys. Fluids 24, 695 (1981)] yields estimates for the “mode width” of magnetic perturbations: in Ohmic discharges, increasing to for 0.6 MW NBI.
Keywords
This publication has 18 references indexed in Scilit:
- Diffusion of runaway electrons in TEXTOR-94Plasma Physics and Controlled Fusion, 1998
- Internal magnetic fluctuations and electron heat transport in the Tore Supra tokamak: Observation by cross-polarization scatteringNuclear Fusion, 1998
- Transport and performance in DIII-D discharges with weak or negative central magnetic shearPhysics of Plasmas, 1997
- Turbulent Fluctuations in TFTR Configurations with Reversed Magnetic ShearPhysical Review Letters, 1996
- Internal Magnetic Turbulence Measurement in Plasma by Cross Polarization ScatteringPhysical Review Letters, 1995
- Islands of Runaway Electrons in the TEXTOR Tokamak and Relation to Transport in a Stochastic FieldPhysical Review Letters, 1994
- Runaway electrons as a diagnostic of magnetic fluctuations in the edge plasma of the Texas Experimental TokamakPhysics of Fluids B: Plasma Physics, 1992
- Estimating the runaway diffusion coefficient in the TEXT tokamak from shift and externally applied resonant magnetic-field experimentsPhysics of Fluids B: Plasma Physics, 1991
- Measurements of fluctuations in the flux of runaway electrons to the PLT tokamak limiterPhysics of Fluids, 1983
- Transport of runaway and thermal electrons due to magnetic microturbulencePhysics of Fluids, 1981