Deuterium retention in TiC and TaC doped tungsten at high temperatures

Samples made of tungsten doped either with titanium carbide (W-1.1TiC) or tantalum carbide (W-3.3TaC) were either exposed to D-2 gas at a pressure of 100 kPa at 800-963 K or irradiated by 38 eV/D ions at 800 K. The deuterium (D) inventory in the samples was examined by nuclear reaction analysis and thermal desorption spectroscopy. The D bulk concentration and total retention in W-3.3TaC were comparable in all cases to that in pure polycrystalline W. The D bulk concentration in W-1.1TiC was more than one order of magnitude higher than that in pure W after exposure to D-2 gas, and was also several times higher than that in W-1.1TiC after irradiation at 800 K. It is suggested that D trapping inside the carbide precipitates in W-1.1TiC becomes essential at high temperatures. (C) 2014 Elsevier B.V. All rights reserved.