@article{9288,
  author = {J. Hargreaves and J. W. M. Vernimmen and J. Scholten and S. Brons and T. W. Morgan},
  title = {Development of an in operando uniaxial fatigue testing regime for the linear plasma device Magnum-PSI},
  abstract = {Tokamak divertors may be exposed to cyclic thermomechanical loads during service, giving rise to the fatigue cracking of plasma-facing monoblocks. Fatigue is a surface-sensitive dislocation-mediated degradation phenomenon, and monoblock fatigue life may be affected by plasma-material interactions such as D/T/He implantation, blistering, fuzz, and ELMs that modify the morphology, microstructure and mechanical response of the plasma-facing surface. To investigate the synergistic effects of plasma-material interactions on fatigue cracking, a novel experimental method has been developed for the Magnum-PSI linear plasma device that combines cyclic thermomechanical loading with simultaneous plasma exposure. A DEMO strikepoint sweeping scenario (45 MW m−2 at 1 Hz over 100 mm span) is translated into experimental parameters via time-dependent thermal–mechanical finite element modelling of a monoblock, which calculated the uniaxial strain imposed at the centre of the plasma-facing surface to be 0.648%. The cyclic thermal loading of ITER-grade W targets is achieved in Magnum-PSI via sinusoidal modulation of the plasma source, with real-time monitoring via synchronous Thomson scattering, optical emission spectroscopy, pyrometry, and infrared thermography. Initial results are presented which demonstrate a proof-of-concept in operando fatigue testing method, qualitatively explore surface roughness/treatment effects, and indicate that strikepoint sweeping may significantly contribute to plasma-facing surface cracking.},
  year = {2026},
  journal = {Nuclear Materials and Energy},
  volume = {47},
  pages = {in press},
  doi = {10.1016/j.nme.2026.102119},
  language = {eng},
}