Theoretical estimation of multiple hydrogen isotope content in metal layers slowly co-deposited from plasmas

A probabilistic and diffusion-based model describing concentrations of multiple hydrogen isotopes simultaneously co-depositing with slowly grown metal layer is given. The conditions modeled are identical to stationary ion implantation into bulk material with infinite fluence. Ratios of different multiple hydrogen isotopes occupying same trapping sites in metal layers co-deposited from plasma are estimated. It is shown that if hydrogen isotopes have different detrapping energies in regards to the same trap (vacancy, dislocation, etc.), only the concentration of the isotope with highest detrapping energy decreases monotonously with deposition temperature. The uncertainty of tritium concentration in co-deposited layer based on the uncertainty in detrapping energy of tritium and deuterium is evaluated; for an 0.01 eV difference, a >10% tritium concentration uncertainty is predicted.