In future D--T tokamak power r e a c t o r s the t he rma l f luxes f r o m the p l a sma to the wall will be 0.4-1 M W / m 2. With a p l a s m a t e m p e r a t u r e of 10-20 keV at the axis of the r e a c t o r , a densi ty n ~ 102~ m "s, and a smal l f rac t ion of multiply charged impuri ty ions, radia t ion may play only a s econd-o rde r ro le in the r emova l of energy f r o m the r e a c t o r , The r equ i red t h e r m a l f luxes may occur if turbulence develops in the p l a sma volume due, e.g. , to the t rapped par t ic le instabi l i ty which is cha rac t e r i zed at high t e m p e r a t u r e s by l a rge t r a n s por t coefficients [1]. The r e a c t o r walls would then be in contact with a hot p l a sma (T ~ 3 keV) and be bombarded by pa r t i c l e s with energ ies grea t ly in excess of the sput ter ing threshold of the wall m a t e r i a l . Thus, power r e ac to r des igns include the use of d ive r to r s which at tenuate the flux of pa r t i c l e s and energy to the f i r s t wall by two o r d e r s of magnitude.