Codeposition of hydrogen with beryllium, carbon and tungsten

Deuterium trapping in tungsten deposition layers formed by deuterium plasma sputtering

“…In experiments with 1.5 keV D ions no co-deposition of reflected deuterium with sputtered tungsten was observed at room temperature. It was therefore concluded that the concentration of D atoms in the W deposition layer was below a few percent [4]. On the other hand, in W layers deposited in a hydrogen RF plasma at a substrate temperature of about 430 K, the ratio of hydrogen to tungsten atoms was observed to be 0.15 H/W [5].…”

“…[3] and references therein). However, only limited experimental investigations aimed at understanding hydrogen isotope retention in W layers deposited on collector probes due to sputtering of W targets with deuterium ions [4] and hydrogen and deuterium plasmas [5,6] have been performed. In experiments with 1.5 keV D ions no co-deposition of reflected deuterium with sputtered tungsten was observed at room temperature.…”

“…The tungsten concentration in the deposition layers was determined by Rutherford backscattering spectrometry, whereas the D( 3 He,p) 4 He nuclear reaction at different 3 He energies was used for quantitative D depth profiling.…”

Hydrogen retention in ITER relevant mixed material layers

“…1. In RBS, the amount of each element is given as areal density [atoms/cm 2 ], hence the layer thickness was determined by calculating from the areal density of each element and theoretical density of each pure material (Be: 1.8 g/cm 3 , C: 2.2 g/cm 3 , W: 19.3 g/cm 3 ). The C layer on Be sample annealed at 773K developed to a resulting mixed layer with a Be/C ratio of 2:1, which indicated the formation of a Be 2 C phase.…”

“…Although various investigations have been done to clarify the hydrogen retention properties of each pure material, there are only a few available data for mixed materials at present [3][4][5][6][7]. In this study, representative mixed material layers of Be, C and W were prepared, and hydrogen retention in those layers was investigated under controlled laboratory conditions.…”