DiMES studies of temperature dependence of carbon erosion and re-deposition in the lower divertor of DIII-D under detachment

Tutkimustuotos: Lehtiartikkelivertaisarvioitu

Tutkijat

  • D. L. Rudakov
  • W. Jacob
  • K. Krieger
  • A. Litnovsky
  • V. Philipps
  • W. P. West
  • C. P C Wong
  • S. L. Allen
  • R. J. Bastasz
  • J. A. Boedo
  • N. H. Brooks
  • R. L. Boivin
  • G. De Temmerman
  • M. E. Fenstermacher
  • E. M. Hollmann
  • C. J. Lasnier
  • A. G. McLean
  • R. A. Moyer
  • P. C. Stangeby
  • W. R. Wampler
  • J. G. Watkins
  • P. Wienhold
  • J. Whaley

Organisaatiot

  • Lawrence Livermore National Laboratory
  • University of California at San Diego
  • Max-Planck-Institut für Plasmaphysik
  • Jülich Research Centre
  • General Atomics
  • Sandia National Laboratories CA
  • University of Basel
  • University of Toronto
  • Sandia National Laboratories

Kuvaus

A strong effect of a moderately elevated surface temperature on net carbon deposition and deuterium co-deposition in the DIII-D divertor was observed under detached conditions. A graphite DiMES sample with a 2 mm wide, 18 mm deep gap lined with silicon catcher plates was exposed to lower-single-null (LSN) L-mode plasmas first at room temperature, and then pre-heated to 200 °C by a built-in electrical heater. At the elevated temperature, deuterium co-deposition in the gap was reduced by an order of magnitude. At the plasma-facing surface of the pre-heated sample net carbon erosion was measured at a rate of 3 nm s-1, whereas without pre-heating net deposition is normally observed under detachment. In a related experiment three sets of molybdenum mirrors recessed 2 cm below the divertor floor were exposed to identical LSN ELMy H-mode discharges. The first set of mirrors exposed at ambient temperature exhibited net carbon deposition at a rate of up to 3.7 nm s-1 and suffered a significant drop in reflectivity. In contrast, two other mirror sets exposed at elevated temperatures between 90 and 175 °C exhibited practically no carbon deposition and their optical reflectivity in the wavelength range above 500 nm was essentially preserved.

Yksityiskohdat

AlkuperäiskieliEnglanti
Sivut29-34
Sivumäärä6
JulkaisuPhysica Scripta
VuosikertaT128
TilaJulkaistu - 2007
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

ID: 4083183