Use of MeV energy ion accelerators to simulate the neutron damage in fusion reactor materials

This paper describes experimental techniques for irradiation of fusion reactor materials with MeV energy ions. The studies were conducted at the NRC "Kurchatov Institute" – ITEP. Two MeV-range linear ion accelerators were used for sample irradiation: the Heavy Ion Prototype (HIPr) accelerator with heavy ions and I-2 accelerator with protons. Target chambers of HIPr accelerator were modified to provide the simultaneous irradiation of four 10 × 10 mm² samples at controlled elevated temperatures. Damage rates and profiles were calculated using the SRIM code. HIPr accelerator provided the damage of tungsten samples with 5.6 MeV Fe²⁺ ions at a rate of 0.05 dpa/h. I-2 accelerator was used to irradiate tungsten samples with 22 MeV protons to create a uniform damage profile at a depth of 0–400 μm with a rate of 5 × 10⁻⁷ dpa/h. Irradiation of tungsten samples with high energy protons causes generation of ¹⁸³Re and ¹⁸⁴Re with a half-life period of 70 and 38 days, respectively. Thus, the samples irradiated with a proton fluence of up to 10²⁰ protons/m² are subject to one year aging before manual handling.