Internal Magnetic Fluctuation In The Hl-1m Tokamak

The transport of runaway electrons in hot plasma can be comparatively easily measured by steady state or perturbation experiments, which provide runaway electron diffusivity D-r. The runaway diffusion coefficient has been obtained using four methods: (1) D-r is deduced from Plasma shift experiment; (2) D-r is deduced from its sawteeth oscillations behaviors of HXR flux and of SXR intensity; (3) D-r is deduced from microwave radiation intensity sawtoothing behaviors; (4) D-r is deduced from hard-X-ray bremsstrahlung spectra. The diffusivity can be interpreted in terms of a magnetic fluctuation level. The internal magnetic fluctuations level ((b) over tilde (r)/B-T) is estimated to be about (2-4) x 10(-4) in the HL-1M plasma. The results presented here demonstrate the effectiveness of using runaway transport techniques for determining internal magnetic fluctuations. A profile of the magnetic fluctuation level in the HL-1M can be estimated from D-r.