Deuterium implantation into tungsten nitride: Negligible diffusion at 300Â K

Magnetron-sputtered tungsten nitride (WNx) films deposited on bulk tungsten (W) were used as model system to study the interaction of deuterium (D) plasmas with W walls in nuclear fusion devices during or after N-seeded discharges. D plasma implantation was performed at 300 K with ion energies below 215 eV. WNx composition and thickness was determined by Rutherford backscattering. The deuterium amount in the sample was analyzed by nuclear reaction analysis (NRA). The resolution for D depth profiling was improved compared to standard NRA by consecutive low-energy argon plasma sputtering of the D containing 100-nm-WNx film. It is shown that D is implanted only within the ion penetration range and does not diffuse into deeper layers at 300 K.