The fourth SINQ Target Irradiation Program, STIP-IV

The 4th SINQ Target Irradiation Program (STIP-IV) was performed in 2004 and 2005. More than 1000 specimens from about 40 kinds of materials were irradiated up to 27 dpa and 2300 appm He in the temperature range of 80–550 °C. The majority of specimens were irradiated in helium gas environment. Some specimens were irradiated in contact with lead and lead–bismuth eutectic. Neutron radiography inspections on specimen and target rods were performed before and after irradiation, which revealed some interesting features of the target rods with thermal couples. Neutronic calculations were performed using the proton distribution profile obtained by γ-mapping on the beam window of the AlMg3 target container after irradiation. Irradiation parameters of the specimens such as proton and neutron spectra and fluxes, heat deposition, irradiation dose in terms of displacement damage (dpa), helium and hydrogen concentrations were calculated. Most of the specimens were retrieved. But, more than 360 tensile and TEM specimens were lost due to a leak in a specimen rod occurred during irradiation.