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The present work is intended to renew the interest in a basic understanding of the stationary transport of Heliotron E with direct ion heating in the framework of neoclassical theory. It should be noticed here that the experimental evaluation of {Chi}{sup exp}{sub i} in such a low collisional regime in heliotron/torsatron configuration was for the first time achieved in this study. However, the transport can be enhanced by turbulence, resulting in the degraded conditions like the L-mode of tokamak operation. In this connection this paper also discusses the possible contribution from the drift wave turbulence that is expected to affect the anomaly of the observed heat fluxes. The ion heat transport in the outer region of the plasma was interpreted as being enhanced by the electrostatic drift wave modes on the basis of the proposed diffusivity model. The result obtained through these analyses has stimulated our further efforts for producing a more collisionless regime where the electric field will control the transport. 11 refs., 6 figs.

Recent results of Heliotron E experiment are reviewed. Detailed studies of the plasma transport have been achieved in Heliotron E, in which the plasma wall interaction has been changed using the ECH boronization technique. The boronization realized low-density, high-T{sub i} plasmas whose ion collisionality deeply estended to the 1/{nu}{sub i}** regime. The local electron and ion thermal diffusivities in the NBI plasma are analyzed and discussed by comparison with theory-based transport models. The particle transport in ECH plasmas is investigated with edge fluctuation measurements. Both electrostatic and magnetic fluctuations are well correlated with the global particle confinement. Characteristic structures of the electric field or potential distribution are observed during the particle confinement degradation phase. It is considered that dc convective flow across the last closed flux surface is caused by the potential structure. Edge plasma flows have been discussed in connection with these studies and with asymmetric divertor heat/particle load. 10 refs., 9 figs.

Mach probe measurements of bias-induced ion flows were made in the Interchangeable Module Stellarator (IMS) as a function of neutral pressure and viscosity (which increases with minor radius) and compared to a fluid theory model. Using a probe model for an unmagnetized plasma, the poloidal flow speed measured with a Mach probe agrees with that calculated from momentum balance to within 15%. The dependencies of the measured ion flow magnitudes and decay rates on neutral pressure and viscosity as predicted by the theory are qualitatively observed in the experimental measurements, clearly demonstrating the effects of both ion-neutral collisions and viscosity in the damping of the bias-induced flows. However, the measured flow direction is nearly poloidal, while the theory predicts a predominantly Pfirsch-Schlueter-like toroidal flow. Also the two-dimensional variation at a constant toroidal angle of the parallel electron current was measured in an unbiased plasma. The measured profiles demonstrate the dependence of the current on both the radial pressure gradient and the cosine of the poloidal angle, as predicted by theory. 11 refs., 5 figs.