Hydrogen penetration through the materials is very important for the prediction of the tritium accumulation in materials and tritium penetration into the environment. These processes are connected with the possible loss of expensive thermonuclear fuel from a thermonuclear reactor and with TR safety. The experimental results showed the hydrogen penetration through investigated materials depended greatly on the conditions of the penetration (penetration of the hydrogen from gaseous phase, from the glow discharge plasma, under hydrogen ion bombardment). Preliminary irradiation by the helium ions up to the fluence 1.0 x 10(20)-5.0 x 10(22) ions/m(2) (35 keV He+) caused a strong decrease in hydrogen penetration through investigated materials during hydrogen ion bombardment as well as simultaneous irradiation by hydrogen and helium ions. The results obtained showed that the preliminary implantation of the O,N,C impurities into the surface layer of the sample had a strong effect on the hydrogen penetration through examined materials.
