Effect of nitrogen seeding into deuterium plasma on deuterium retention in tungsten

Influence of nitrogen pre-implantation on deuterium retention in tungsten

“…The amounts of retained N and D in the samples were measured by nuclear reaction analysis (NRA). For D analysis the 2 D ( 3 He, p 0 )  nuclear reaction [9] and for N analysis the 14 N ( 4 He, p 0 ) 17 O reaction [10] were used. The D concentration within the near-surface layer (at depth up to about 0.3 m) was determined at a 3 He + energy of 0.69 MeV by analyzing the emitted  particles with a surface barrier detector at the laboratory scattering angle of 102° equipped with a rectangular slit reducing the solid angle to 9.16 msr.…”

“…As a special case, so-called blisters can be formed at the surface [8,15]. It has been reported frequently that blisters in W vary considerably in terms of their size, shape and abundance depending on exact exposure conditions, such as temperatures, fluence, bias voltage [8] and simultaneously impinging impurity flux [16,17]. Fig.…”

Blistering and re-deposition on tungsten exposed to ASDEX Upgrade divertor plasma

“…The ion impact energy is in the order of tens to hundreds of eV. These exposure parameters fall into the parameter range of blistering studies in laboratory experiments [1][2][3][4][5][6][7][8][9][10][11][12][13].…”

“…Blistering of tungsten (W) materials -caused by the large transient hydrogen supersaturation in the metal -is a phenomenon well documented in laboratory experiments [1][2][3][4][5][6][7], but only sparsely observed in fusion devices [8,9]. The laboratory experiments indicate that the tungsten grade and the surface quality, e.g., polished or technical surface, as well as the impurity content in the incident hydrogen flux play a role in appearance and abundance of blistering and other morphological changes [10,11,12,13]. E.g., a small fraction of helium in the incident ion flux prevents blistering [12].…”

Deuterium retention and morphological modifications of the surface in five grades of tungsten after deuterium plasma exposure

“…All equivalent specimens of rolled Plansee material originate from a single sintering batch to ensure the same initial microstructure and chemical composition. Specimens cut from the same rod of swaged Plansee material as the specimen WP-S were investigated in [18][19][20]. Unfortunately, these specimens [18][19][20] were polished with a different procedure than the recipe described in [26].…”