Hydrogen exchange with voids in tungsten observed with TDS and PA

Ion-driven deuterium retention in tungsten

“…As our calculations show, the essential amount of deuterium will be retained in traps with energy of 2.1 eV at high irradiation temperatures. This kind of traps corresponds to D chemisorptions inside the ion-induced micro-voids, namely chemisorptions on the bubble wall [15]. For the investigated irradiation temperature range of 300-500 K in the present paper, the amount of deuterium in the peak of 1000 K (2.1 eV) is negligible compared to the retained D in the two other peaks.…”

“…Due to the small difference in the trapping energy of a deuterium atom trapped in a vacancy and the trapping energy of deuterium molecules in microvoids or microcavities [13][14][15][16], it may be difficult to resolve these two trap sites experimentally. On the other hand, TDS measurements influence the initial D distribution by annealing.…”

“…But also the ion-induced defect distribution propagates into the bulk of the target. According to van Veen [15] and Nagata [20], the ion-induced damage can extend many times deeper than the implantation depth. The diffusion in the damage zone can differ considerably from the bulk diffusion.…”

Deuterium retention in rhenium-doped tungsten

“…Van Veen et al [14] registered a high-temperature peak at 800 K in the TDS of monocrystalline tungsten irradiated by 200 eV deuterons. Before deuterium implantation the sample was pre-implanted by 6 MeV protons and ∅ 1 nm voids were created in the material.…”

Numerical analysis of TDS spectra under high and low flux plasma exposure conditions

“…H retention is expressed in surface modification, formation of subsurface blisters and accumulation of H in the bulk material. These effects are attributed to trapping of H atoms on lattice defects such as vacancies, dislocations/grain boundaries and voids [2][3][4]. Typical kinetic energy of H ions coming from plasma (below 500 eV ) is far below the threshold energy needed to create a stable Frenkel-pair defect in W, and the implantation range of H ions is limited to several nanometers [5].…”