Adsorption states of protium and deuterium in redeposited polymer hydrocarbon films from a T-10 tokamak

Abstract

Free redeposited hydrocarbon films (flakes) with a high content of deuterium and hydrogen formed in the T-10 tokamak operating at the Russian Research Centre (RRC) "Kurchatov Institute" are studied using thermal desorption spectroscopy (TDS), infrared (IR) spectroscopy, and X-ray diffraction (XRD) analysis. According to the XRD data, the films contain scattering elements with dimensions of about 1 nm and weakly ordered structures. The TDS curves for D2 (H2) consisting of two groups of peaks at 450-800 and 900-1000 K turn out to be sufficiently similar to the spectra of nanographite obtained by milling graphite mechanically. Two main adsorption states with activation energies of ≈0.65 and ≈1.25 eV/N corresponding to hopping diffusion and resonance mechanisms, respectively, were discovered. The difference between the IR spectra of reddish-gold and dark-brown films is due to both a weaker degree of C-H hybridization of dark films and their disordered carbon network whose ends are connected to CD2,3 fragments. © Pleiades Publishing, Ltd., 2009.