@article{bibcite_7714,
  author = {M. H. J. {\textquoteright}t Hoen and M. Mayer and A. W. Kleyn and H. Schut and P. A. Zeijlmans van Emmichoven},
  title = {Reduced deuterium retention in self-damaged tungsten exposed to high-flux plasmas at high surface temperatures},
  abstract = {We investigated the effect of surface temperature on deuterium retention in self-damaged tungsten exposed to high-flux deuterium plasmas. The retention saturates at a W 4+ fluence of about 3 {\texttimes} 10 17  m -2 and is strongly reduced for the present high surface temperatures of 800{\textendash}1200 K as compared with previous experiments at 470{\textendash}525 K. Combination of nuclear reaction analysis (NRA), thermal desorption spectroscopy and positron annihilation Doppler broadening (PADB) was used to investigate the reduction in deuterium retention. The NRA showed a strong reduction of retention at the surface at high surface temperatures. The PADB measurements suggest that during plasma exposure defects are mobile and cluster into larger clusters containing up to a few tens of vacancies. The Tritium Migration Analysis Program 7 simulations show that trapping and de-trapping rates are very high for defects with trapping energies below \~{}1.5 eV. The strong reduction in retention seems to be caused by the reduced amount of mono-vacancies and small vacancy clusters in combination with their strong depopulation due to thermal trapping and de-trapping.
},
  year = {2013},
  journal = {Nuclear Fusion},
  volume = {53},
  number = {4},
  pages = {043003},
  doi = {10.1088/0029-5515/53/4/043003},
  language = {eng},
}