Tritium diffusion coefficients and deuterium solubilities were measured for laminar pyrolytic carbon at 900 to 1500C. The tritium diffusion coefficients were much lower than those for metals at equivalent temperatures, but the activation energy for the diffusion was much higher (∼-100kcal/mol). Tritium diffusion coefficients measured for silicon-doped pyrolytic carbon were over an order of magnitude higher than the values for the undoped laminar pyrolytic carbon. The solubility of deuterium in laminar pyrolytic carbon was found to decrease with increasing temperature and exhibited a pressure dependence of p1/2.

Hydrogen Diffusion and Solubility in Pyrolytic Carbon. Causey, R.A., Elleman, T.S., Verghese, K.: Carbon, 1979, 17[4], 323-8