Main directions and recent test modeling results of lithium capillary-pore systems as plasma facing components

At present the most promising principal solution of the divertors problem appears to be the use of liquid metals and primarily of lithium Capillary-Pore Systems (CPS) as of plasma facing materials. A solid CPS filled with liquid lithium will have a high resistance to surface and volume damage because of neutron radiation effect, melting, splashing and thermal stress-induced cracking in steady state and during plasma transitions to provide the normal operation of divertor target plate and first-wall protecting elements. These materials will not be the sources of impurities inducing an increase of Zeff and they will not be collected as dust in the divertor area and in ducts. Experiments with lithium CPS under simulating conditions of plasma disruption on the hydrogen plasma accelerator MK-200 [∼(10-15) MJ/m2, ∼15 μs] have been performed. The formation of a shielding layer of lithium plasma and the high stability of these systems has been shown. The new lithium limiter tests on an up-graded T-11M tokamak (plasma current up to 100 kA, pulse length ∼0.3 s) have been performed. Sorption and desorption of plasma-forming gas, lithium emission into discharge, lithium erosion, deposited power of the limiter are investigated in these experiments. The first results of experiments are presented. (authors)