Secondary Effect of Nitrogen on Hydrogen Isotopes Retention in Tungsten Dust from Fusion Reactor Simulated by Wire Electrical Explosion

Nitrogen is potentially used in tokamak as seed impurity for avoiding divertor damage and achieving good plasma performance. Herein, the secondary effect of nitrogen was studied by wire electrical explosion (WEE) method. In the presence of nitrogen, the inventory of hydrogen retention in the tungsten dust was largely increased, while hydrogen was retained by chemical bonding with nitrogen, besides dissolving into lattice and trapping in defects of tungsten, which was identified by FTIR and XRD. This study indicates that nitrogen seed impurity will cause serious tritium retention and speed tungsten-based plasma facing components (PFC)' erosion.