Deuterium retention in plasma spray tungsten coatings exposed to low-energy, high flux D plasma

作者：Alimov V Kh^*; Nakamura H; Tyburska Pueschel B; Ogorodnikova O V; Roth J; Isobe K; Yamanishi T

来源：Journal of Nuclear Materials, 2011, 414(3): 479-484.

DOI：10.1016/j.jnucmat.2011.05.041

Two types of porous plasma spray tungsten coatings deposited onto stainless steel and graphite substrates were exposed to low-energy (76 eV D-2(-)), high-flux (10(22) D/m(2) s) D plasma to ion fluences of (3-4) x 10(26) D/m(2) at various temperatures. Deuterium retention in the W coatings was examined by thermal desorption spectroscopy and the D(He-3,p)He-4 nuclear reaction, allowing determination of the D concentration at depths up to 7 mu m. The relatively high D concentration (above 0.1 at.%) at depths of several micrometers observed after D plasma exposure at 340-560 K can be related to accumulation of D-2 molecules in pores, while at temperatures above 600 K deuterium is accumulated mainly in the form of D atoms chemisorbed on the inner pore surfaces. At exposure temperatures above 500 K, the D retention in the plasma spray W coating on graphite substrate increases significantly due to trapping of diffusing D atoms at carbon dangling bonds located at the edge of a graphite crystallite.

• 出版日期2011-7-31