Ion beam studies of H and He in metals

Structure, stability and diffusion of hydrogen in tungsten: A first-principles study

“…The results of formation energies in Table 1 show that the tetrahedral interstitial site is energetically more favorable for single H, in good agreement with both computational [7] and experimental results [13][14][15][16]. For comparison, we also calculated formation energy of single vacancy, which is 3.14 eV for the 54-atom supercell and 3.11 eV for a 128-atom supercell, consistent with the calculated values from Becquart and Domain [17].…”

The Depths of Hydrogen and Helium Bubbles in Tungsten: A Comparison

“…site. [63][64][65][66] A hydrogen atom at the tetrahedral site has four nearest-neighbor tungsten atoms, each at a distance of 1.91 Å. In the perfect hydrogen-free unrelaxed lattice, the corresponding distance is 1.77 Å.…”

Energetics of He and H atoms with vacancies in tungsten: First-principles approach

“…The deleterious effects of He and H on the properties of metals and alloys have been well known and extensively documented. The degree of damage is more profound under high-energy irradiation that generates significant concentrations of transmuted H and He [1]. In the case of irradiated tungsten, the resulting damages include various microscopic defects such as surface modifications, erosions, and formations of craters, clusters and bubbles [2][3][4][5][6][7][8][9][10].…”