Microscopic damage of tungsten exposed to deuterium-helium mixture plasma in PISCES and its impacts on retention property

作者：Miyamoto M^*; Nishijima D; Baldwin M J; Doerner R P; Ueda Y; Yasunaga K; Yoshida N; Ono K

来源：Journal of Nuclear Materials, 2011, 415(1): S657-S660.

DOI：10.1016/j.jnucmat.2011.01.008

Microscopic damage and D retention in tungsten have been investigated for low-energy (similar to 60-120 eV), high flux (similar to 10(22) m(-2) s(-1)) high fluence (similar to 5 x 10(25) m(-2)) ion bombardment at moderate temperature (similar to 573-773 K) in mixed species D + He plasmas in the linear divertor plasma simulators PISCES-A and B. A significant reduction in D retention and the formation of nanometer-sized He bubbles occur in W due to seeding of He into the D plasma. The volume fraction of He bubbles, estimated with TEM observations and ellipsometric measurements, exceeds the percolation threshold. The desorption mechanism that injected D atoms diffuse back to the surface through the percolating bubbles is suggested. The seeding of Be into D + He mixture plasma eliminates this He effect on the reduction in D retention.

• 出版日期2011-8-1