Experimental study of the Texas turbulent torus

Both the preheat and turbulent phase plasmas produced in the Texas Turbulent Torus discharge have been studied using microwave interferometry, Langmuir probe scans, Thompson scattering, microwave radiation detection, and an E vector x B vector velocity analyzer to obtain a picture of the evolution of the plasma during both phases of the discharge. A cool, uniform, well understood preheat plasma is produced which is subjected to a large toroidal electric field during the turbulent phase. The electron velocity distribution is measured during turbulent heating using an E vector x B vector velocity analyzer. A turbulent skin arises on the plasma edge which penetrates into the higher density (> 3 x 1012cm-3), interior portion of the plasma on a microsecond time scale. Large drift velocities (v/sub d/ > v/sub Th/) and non-Maxwellian temperatures of several KeV are characteristic of the turbulent plasma. During the turbulent phase of the discharge large heating rates (12KeV/μs) are observed together with rapid energy losses from the edge of the plasma and less rapid losses from the interior. The non-Maxwellian velocity distributions provide an explanation for observed inconsistencies between laser, x-ray, and magnetic probe measurements while showing agreement with each measurement individually