Hydrogen isotope distributions and retentions in the inner divertor tile of JT-60U

Distribution of hydrogen isotopes retained in the divertor tiles used in JT-60U

“…We have been studying the retention of hydrogen isotopes (H, D, T) in plasma facing graphite tiles used in the W-shaped divertor of JT-60U with the inner side pumping system [3,[5][6][7][8][9] and with the dual side pumping system [10][11][12]. We found that most of the tritium produced by D-D reactions was implanted into graphite tiles in the micrometer depth range, while hydrogen and deuterium were retained in the near surface region and the retention was influenced by the carbon deposition as well as the surface temperature of the tiles.…”

“…compares thermal desorption spectra of H 2 , HD, D 2 and CH 4 for sample #2 from the plasma facing surface of the inner divertor tiles (a), sample #11 from the plasma facing surface of the outer divertor tiles eroded to a depth of about 15 lm[11] (b) and sample #9 from the top side surface of the outer dome wing tile facing toward the pumping slot (c).…”

Hydrogen isotope behavior in the first wall of JT-60U after deuterium plasma operation

“…We have extensively studied retention characteristics of hydrogen (H), deuterium (D) and tritium (T) in the JT-60U divertor area [6][7][8][9][10][11][12][13] and found that most T produced by DD reactions was implanted into graphite tiles at the depth of a few lm. However, H and D were retained in the near surface area.…”

Retention and depth profile of hydrogen isotopes in gaps of the first wall in JT-60U

“…For this reason, it is important to investigate retention behavior of hydrogen isotopes in present tokomaks for prediction of tritium retention in ITER. In tokamaks, hydrogen (H) and deuterium (D) retention and carbon erosion/ deposition in the divertor area has been intensively investigated so far [2][3][4][5][6][7][8][9][10][11][12]. In JT-60U, it was found that the H + D retention in the plasma facing surface and the side surface of the graphite tile in the divertor area is of the order of about 10 22 -10 23 atoms/m 2 .…”