Preliminary study on transient thermal shock behavior of high purity tungsten

The thermal shock performances of ITER-like high purity tungsten were examined by an electron beam heat load test and finite element code simulation. Experiments under ITER-like plasma major disruption instability happening condition with test sample background temperature at room temperature were simulated by an electron beam facility EMS-60 newly constructed. Recrystallization, cracking and melting behaviors of test sample after irradiation tests were observed by a scanning electron microscopy (SEM) and their formation mechanisms have been discussed. Finite element simulation has been carried out by ANSYS code and the result shows that the cracking threshold of ITER grade tungsten is about 1.5 MJ·m^-2 for 5 ms pulse loading, which is in accordance with experimental results. (authors)