• Brezinsek, S.
• Van Rooij, Gerardus
• Al, R. S.
• Temmerman, G. C. De
• Kirschner, A.
• Philipps, V.
• Pol, Marc J. Van De
• Meiden, H. J. Van Der
• Cardozo, Niek Lopes
• Vijvers, W. A. J.
• Borodin, D.
• Westerhout, J.
• Lisgo, S. W.
• Shumack, A. E.
• Hoen, M. H. J. T.
• Wright, G. M.
• Rapp, J.

Abstract

<p>We have studied the chemical erosion of different carbon composites in Pilot-PSI at ITER-relevant hydrogen plasma fluxes (∼10²⁴ m ^-2 s^-1) and low electron temperatures (T_e∼1 eV). Optical emission spectroscopy on the CH A-X band was used to characterize the chemical sputtering. Fine grain graphite (R 6650, SGL Carbon Group), ITER-reference carbon fiber composite material (SNECMA NB31 and NB41; Dunlop 3D), nano- and micro-crystalline diamond coatings on molybdenum and SiC (Silit® SKD Reaction-Bonded, Saint-Gobain Ceramics) were compared. The chemical sputtering was similar for the different composites under comparable plasma conditions, except for SiC, which produced a ten times lower rate. The CH emission was constant at electron temperatures T_e&gt;1 eV and ion fluxes ranging between 10²³ and 10²⁴ m^{- 2} s^-1, but decreased at lower temperatures. This decrease is possibly due to changes in the excitation of CH and not due to a change in the chemical erosion rate.</p>

Topics

• impedance spectroscopy
• molybdenum
• Carbon
• grain
• composite
• Hydrogen
• ceramic