Feedback control of highly radiative plasmas in Tore Supra

The first Tore Supra experiment dedicated to plasma detachment is reported. A criterion of detachment is deduced from bolometric measurements. This cr iterion is used to feedback control gas injection and maintain plasmas atta ched. Due to changes in plasma properties when detachment is approached, th e feedback loop is unstable. Nevertheless, radiated power is maintained alm ost constant at 85% of the total injected power during ohmic discharges. Fe edback control of gas injection on radiated power during ICRH discharges is reported. It allows to maintain high radiated power (up to 80% of the tota l injected s MW power) and to reduce conducted power on the ergodic diverto r tiles with a plasma edge temperature maintained below 15 eV. (C) 1999 Els evier Science B.V. All rights reserved.