Composition and hydrogen isotope retention analysis of co-deposited C/Be layers

• Published in: Journal of nuclear materials Vol. 337-339; pp. 590 - 594
• Main Authors: Baldwin, M.J., Schmid, K., Doerner, R.P., Wiltner, A., Seraydarian, R., Linsmeier, Ch
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2005
• Subjects: Desorption; Deuterium inventory; Erosion and deposition; PISCES-B; 73.61.−r; C0100; 73.50.−h; Erosion and deposition; 52.40.Hf; R0100; Desorption; B0100; PISCES-B; Deuterium inventory; 52.77.Dq
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2004.09.043

A neutral Be atom source and deposition probe have been installed on PISCES-B to simulate ITER diverter erosion and deposition phenomena where Be impurity concentration in the plasma, up to 10%, is expected due to first wall erosion. Graphite target erosion by deuterium plasma is found to be significantly reduced with as little as ∼0.1% Be impurities in the plasma [K. Schmid, M.J. Baldwin, R. Doerner, these Proceedings]. Deposited Be on the target is re-eroded and leads to deposited layers in the target vicinity, that are sampled with the deposition probe. These layers are Be rich and contain only small C concentrations (<3at.%). The ratio of co-deposited deuterium to deposited beryllium (D/Be) decreases rapidly with increasing probe temperature up to 573K. D/Be values are systematically lower and O/Be values higher compared to similar experiments in TPE [R.A. Causey, D.S. Walsh, J. Nucl. Mater. 254 (1998) 84]. The difference is likely due to different target-collector geometries and incident hydrogen isotope fluxes during collection.