2-7«-a»-3073 . tlSTl>t8UH0» Of THIS MCilMENI IS MHUKD i'X-^1: DISCLAIMER This rc|Kirl was prepared as an account of woiX sponsored i>y an agency of Ihc United States (tovcrnmcnl. Neither the United Slates fjovctnmcnl nor any-agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or use fulness of any information, apparatus, product, or process disclosed, or represents that its use would

more »

... nol infringe privately owned rights. Reference herein lo any spe cific commercial product, process, or service by trade name, uauematV, manufac turer, or otherwise does nol necessarily constitute or imply its endorsement, recom mendation, or favoring by the United Slates Ciovernment or any agency thereof. The views and opinions of authors expressed herein do nol necessarily slate or reflect those of the Uniicd Slates Government or arty agency ;hcrcv,". ABSTRACT Toroidal and poloidal rotation has been measured in the Poloidal Divertor Ex periment (PDX) tokamak in ohinicand neulral-beam-heatod plasmas in a variety of discharge conditions and in both circular and diverted configdrations. Rota tion velocities were deduced from Doppler shifts of magnetic dipolc (Ml) lines and lines of optically allowed transitions iu the visible and UV regions, from K" emission, and also from an array of magnetic pickup loops. Poloidal and toroidal rotation velocities in ohmically heated discharges were usually less than 3 X 10 s cm/sec. Near the plasma edge the toroidal rotation velocity varies with poloidal angle both before and during neutral-beam injection. No systematic poloidal rotation was observed during neutral-beam injection centered about or displaced 10 cm from the horizontal tnidplanc, which implies that the poloidal damping time TQ < 0.5r,j, consistent with theoretical estimates. The central toroidal rotation velocity during > <:iitral-bcam injection scales linearly with the quantity l\b s /n^ and is independent of plasma current and toroidal magnetic field. The toroidal rotation velocity is higher in deuterium than in hydrogen, plasmas, and also in diverted as compared with circular discharges. Toroidal rotation decay times after injection range from 80-100 msec at the center to lftO-180 msec at half the minor radius. Modeling of the radial profile of toroidal rotation indicates a central momentum diifusivity on th*" order of 8x 10 3 cm' J /sec. This is approximately a factor of three higher than the momentum diiTusivity obtained from the decay time. All present theories are inadequate in accounting for the observed damping rate of v v . Current address: Association ISuratom-CIiA sur la fusion, 13cpartcmc.nl dc rcchcrchcs sur la fusion coolrolce, Centre d'etudes nuclcaircs,