CESS

An activity within the Steel Surfaces CRP, the Comparison Experiment for the Sputtering of Steel (CESS) is a set of coordinated experiments on steel surfaces to compare sputtering yields in different experimental devices. As far as possible, identical samples (with comparable histories) will be exposed to deuterium plasma or ion irradiation under comparable exposure conditions.

Sample provision and experimental conditions

  • Steel samples to be considered:
    • Pure Fe
    • Eurofer-97
    • Rusfer
    • CLAM
    • F82H
  • All samples 10 × 10 × 1 mm or 12 × 15 × 1 mm; mechanical polishing, annealed at 870 K for 1 hr
  • Ion energy: 200 eV
  • Ion species: D
  • Sample temperature (where defined): 450 K
  • Ion fluence: 5 × 1024 D m-2
  • Ion flux: variable (this will depend on the experimental capabilities of the devices used)

Sample analysis techniques

Certainly:

  • Mass loss (to determine sputter yield)
  • SEM (surface imaging before and after sputtering)
  • TDS (for total retained D amount)

If possible (in decreasing order of priority):

  • EBSD (before and after exposure at the same area to look for grain-dependent effects)
  • EDX (to check for W enrichment at the surface)
  • FIB cross sectioning (+ EDX)
  • TEM
  • Ion beam analysis for enrichment
  • NRA for D depth profiling
  • XPS depth profiling (compare before and after exposure to document changes in surface composition)
  • Optical spectroscopy (during erosion to identify dynamic changes; PISCES, for example provides this facility)
  • GDOES (composition depth profiling, to identify W enrichment at the surface)