LASER APPLICATION IN THE CURRENT PROFILE CONTROL AND PRESSURE DISTRIBUTION IN TOKAMAKS AND STELLARATORS

Physical grounds are discussed for the laser control of the current an d plasma pressure distribution profiles. The mechanism of generation i s discussed of a noninductive current drive under laser irradiation of a frozen-hydrogen pellet from the plasma volume; a possibility of arr angement of the peaked profiles of the current is shown; the estimates of the bootstrap current are made. It is noted that by using the lase r methods, one can excite, among the others, the local currents with t he reverse charge motion in respect to the initial ohmic current. One can, thus, provide the optimal current distributions, from the viewpoi nt of the magnetic plasma confinement, and hence, the profiles of the stability safety coefficient, and the value and sign of 'shear'. The p ressure (density) distribution is controlled by a time-programmed lase r pulse irradiation of a moving pellet. (C) 1998 Elsevier Science S.A. All rights reserved.