Modeling of beryllium deposition from a beryllium-seeded deuterium plasma

This paper is concerned with modeling the formation of beryllium (Be) layers deposited from a Be-seeded deuterium (D) plasma. In recent experiments at the PISCES-B divertor simulator [Y. Hirooka , J. Vac. Sci. Technol. A 8, 1790 (1990)] at UC-San Diego, C targets biased at -50 V were exposed to a Be-seeded D plasma in the temperature range from 500 to 1280 K and Be plasma concentrations in the range from 0.01% to 0.4%. It was found in [K. Schmid, M. Baldwin, R. Doetner, and A. Wiltner, Nucl. Fusion 44, 815 (2004)] that even at these low Be concentrations the C samples become covered with a shielding Be layer which almost eliminates chemical and physical erosions of the C sample in the observed target temperature range. Three different approaches were used to model these experimental results: the well-established binary collision Monte Carlo code TRIDYN [W. Moller, W. E. Und, and J. P. Biersack, Comput. Phys. Commun. 51, 355 (1988)], the recently developed plasma surface interaction code GWAR, and analytical expressions were compared. The paper explains the details of the developed models and how their results compare to the experiment. (C) 2005 American Institute of Physics.