Particle Transport Due to Magnetic Fluctuations

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 ($E>\mathrm{}{T}_{\mathrm{ea}}$) due to parallel streaming along a fluctuating magnetic field is determined locally by measuring the correlated product $〈{\tilde{J}}_e{\tilde{B}}_r〉$. Particle transport is small just inside the last closed flux surface (${\Gamma }_{e,\mathrm{mag}}<0.1\mathrm{}{\Gamma }_{e,\mathrm{total}}$), but can account for all observed particle losses inside $\frac{r}{a}=0.85\mathrm{}$. Electron diffusion is found to increase with parallel velocity, as expected for diffusion in a region of field stochasticity.