Behaviour of tungsten alloy with iron and nickel under repeated high temperature plasma pulses

Abstract

The changes of the structure and properties of a dual phase tungsten (W) alloy (with either 3 % or 5 % of an added mixture of Fe and Ni) are investigated after irradiation with powerful deuterium plasma pulses. The interplay of very powerful plasma pulses, comparable with the off-normal events of ITER or plasma pulses with heat flux factor values comparable with ELMs, is studied. We show that the size of characteristic damage that develops on the irradiated surface follows the size of the tungsten grains. The Fe and Ni alloy plays the role of shock absorber between the grains of the material, and disables the development of cracks both on the surface and within the bulk. The results are discussed and compared to previous results obtained for pure double and single forged W.