Some recent Russian studies of hydrogen isotope retention in plasma facing materials

Abstract

Russian studies of hydrogen isotope retention in plasma facing materials of the International Thermo-nuclear Experimental Reactor included the analysis of carbon–deuterium flakes, formed in the vacuum chamber of the T-10 tokamak, as well as modelling of normal reactor operation conditions and plasma disruptions. The decrease in the [D]/[C] atomic ratio and the decrease in the mass of flakes when these flakes were annealed in air and water steam against temperature were determined. Using Fourier transform infrared reflection spectroscopy, we found that deuterium is accumulated in the flakes only in two states: in the C‒ D2 sp3 deformation modes at 633 and 1090 cm−1 and in the C‒ D2, 3 sp3 stretching modes at 2100–2200 cm−1. In co-deposited Be+D films the [D]/[Be] atomic ratio decreases from 0.15 at 375 K to 0.05 at 575 K. Carbon impurities in the Be+D films slightly increases deuterium retention. The effect of plasma disruptions on deuterium retention in tungsten is described.