By using ultra-high vacuum techniques and mass-spectroscopic analysis, an investigation was made of the permeation of H through a drawn 3N-purity Mo tube at pressure and temperature ranges of 10-6 to 200torr and 1050 to 2400K, respectively. At low driving pressures, the permeation was controlled by phase-boundary processes. At pressures above 1torr, the data obeyed:

P (torr½ l/cm s) = 7.1 x 10-4 exp[-21.5(kcal/mol)/RT]

Permeation of Hydrogen through Tungsten and Molybdenum. R.Frauenfelder: Journal of Chemical Physics, 1968, 48[9], 3955-65