Initial results for ion-induced release of hydrogen and deuterium from AXF-5Q graphite by hydrogen and deuterium

The ion-induced release of hydrogen and deuterium from AXF-5Q graphite has been measured for hydrogen and deuterium ions with energies near 200 eV. The experimental data obtained are analyzed to determine the ion-induced release cross section and the location and release of the additional retained hydrogen (i.e., that not retained in the surface layer). Two different approaches were used to model the release of the additional hydrogen. The model that treats the additional retained hydrogen (deuterium) as having migrated deeper into the graphite on grain surfaces produces results that are consistent with experimental data, whereas the model that treats the additional retained hydrogen as being trapped in a codeposited layer produces results that are inconsistent with experimental data. The ion-induced release cross section is determined to be in the range (1–2)×10−17 cm2.