Helium pressure Effect on Cavity Growth Rate in Irradiated Metals

To explain the radiation induced swelling phenomena, the method with rate theory has been used from 1980's. The method can be applied more conveniently than the kinetic Monte Carlo method. Mansur showed the contents of helium affected the cavity growth rate severely. Several equations have been suggested. But it is hard to find a suitable equation under a condition of high temperature and high pressure. The helium content in bubbles has been calculated under an assumption that helium cannot be soluble in the matrix of metals and exists only in the cavity. But the helium atoms can form as small voids because the binding energy of helium and vacancy is high. To estimate the growth rate of cavities, the effect of the gas pressure on the rate is particularly needed. We reviewed that the value of cavity growth rate varied at different equations of state and gas pressure under same helium content and temperature