Enhanced confinement discharges in DIII-D with neon and argon induced radiation

Enhanced energy confinement in discharges with impurity induced radiating p ower fractions, P-rad/P-in, from 50% to 100% have been observed in the DIII -D tokamak with neon and argon gas puffing. These radiating mantle enhanced confinement discharges have been obtained in the DIII-D tokamak under a va riety of conditions: diverted and limited configurations with both an H-mod e and L-mode edge. Confinement enhancements as high as the ELM free H-mode scaling relation have been obtained with impurity gas puffing, although ope ration at the highest densities is transient. Similarities and differences between these DIII-D discharges and RI-mode discharges obtained in the TEXT OR tokamak are discussed. (C) 1999 Elsevier Science B.V. All rights reserve d.