Effects Of Repeated Short Heat Pulses On Tungsten

Effects of ELM-like repeated short heat pulses on tungsten have been studied by using a fundamental wave (wave length of 1064 nm, the pulse length of 130 mu s) of a Nd/YAG laser. Tungsten temperature was 773 K or 473 K. The energy absorption rate of the laser light was about 30% for mirror-finished surface. After 10,000 shots at an incident energy fluence of 7 J/cm(2) (melting threshold was about 150 J/cm(2)), the cracks formation was still observed. Surface roughening and cracking were more pronounced for tungsten samples with surface impurity mixing layers (carbon and oxygen). (C) 2010 Elsevier B.V. All rights reserved.