Particle transport due to magnetic fluctuations.

Abstract

Electron current fluctuations are measured with an electrostatic energy analyzer at the edge of the MST reversed-field pinch plasma. The radial flux of fast electrons ($E>{T}_{\mathrm{ea}}$) due to parallel streaming along a fluctuating magnetic field is determined locally by measuring the correlated product $〈{\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{J}}_{e}{\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{B}}_{r}〉$. Particle transport is small just inside the last closed flux surface (${\ensuremath{\Gamma}}_{e,\mathrm{mag}}<0.1{\ensuremath{\Gamma}}_{e,\mathrm{total}}$), but can account for all observed particle losses inside $\frac{r}{a}=0.85$. Electron diffusion is found to increase with parallel velocity, as expected for diffusion in a region of field stochasticity.