Major results of the cooperative program between JAERI and universities using plasma facing materials in JT-60U

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

“…In JT-60U, however, the hydrogen isotope retention was much smaller than that observed in other tokamaks, which was attributed to high operation temperature [1,3,4]. In addition, HH discharges performed to remove tritium made the depth profiles of hydrogen and deuterium very complex.…”

“…Such deuterium retention characteristics in JT-60U were significantly different from those observed in other tokamaks [1,3,4]. This motivates us to make detailed analysis of hydrogen and deuterium retentions in the inner divertor target tile in terms of poloidal position, deposition/erosion and temperature.…”

“…According to recent retention studies of hydrogen isotopes (hydrogen, deuterium and tritium) in plasma facing graphite 0920-3796/$ -see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.fusengdes.2005.06.074 tiles used in JT-60U, most of tritium was implanted into plasma facing graphite tiles in the depth of micrometer range but not co-deposited with carbon, while hydrogen and deuterium were retained in very near surface [3][4][5][6][7]. In addition, hydrogen and deuterium distributions were quite different with each other showing much shallower depth profile for hydrogen.…”

Correlation between hydrogen isotope profiles and surface structure of divertor tiles in JT-60U

“…Recently, plasma-facing graphite tiles exposed to DD discharges in JT-60U at the Japan Atomic Energy Research Institute (JAERI) have been available for research studies for PMI and hydrogen and deuterium/tritium retention [5]. The hydrogen isotope behavior in the tiles during the inner side pumping have been investigated by the tritium imaging plate technique [6][7][8][9], secondary ion mass spectroscopy (SIMS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) [10][11][12].…”

Tritium removal by isotopic exchange

“…In our recent work on hydrogen isotopes retention in plasma facing tiles of JT-60U, we have found that distribution of hydrogen isotopes is quite non-uniform in depth, poloidal and toroidal positions, and eroded and deposited areas. In addition discharge history and tile temperatures significantly modify the depth distribution [3][4][5][6][7][8][9][10].…”