Highly Radiative Plasmas for Local Transport Studies and Power and Particle Handling in Reactor Regimes
Authors: K.W. Hill, M.G. Bell, R.E. Bell, R. Budny, C.E. Bush, D.R. Ernst, G.W. Hammet, D.R. Mikkelsen, H.K. Park, A.T. Ramsey, S.A. Sabbagh, S.D. Scott, E.J. Synakowski, G. Taylor, and M.C. Zarnstorff
To study the applicability of artificially enhanced impurity radiation for mitigation of the plasma-limiter interaction in reactor regimes, krypton and xenon gases were injected into the Tokamak Fusion Test Reactor (TFTR) supershots and high-li plasmas. At neutral beam injection (NBI) powers PB greater than or equal to 30 MW, carbon influxes (blooms) were suppressed, leading to improved energy confinement and neutron production in both deuteriumn (D) and deuterium-tritium (DT) plasmas, and the highest DT fusion energy production (7.6 MJ) in a TFTR pulse. Comparisons of the measured radiated power profiles with predictions of the MIST impurity transport code have guided studies of highly-radiative plasmas in the International Thermonuclear Experimental Reactor (ITER). The response of the electron and ion temperatures to greatly increased radiative losses from the electrons was used to study thermal transport mechanisms.