First tests of diagnostic mirrors in a tokamak divertor: An overview of experiments in DIII-D

Tutkimustuotos: Lehtiartikkeli

Tutkijat

  • A. Litnovsky
  • D. L. Rudakov
  • G. De Temmerman
  • P. Wienhold
  • V. Philipps
  • U. Samm
  • A. G. McLean
  • W. P. West
  • C. P C Wong
  • N. H. Brooks
  • J. G. Watkins
  • W. R. Wampler
  • P. C. Stangeby
  • J. A. Boedo
  • R. A. Moyer
  • S. L. Allen
  • M. E. Fenstermacher
  • C. J. Lasnier
  • R. L. Boivin
  • A. W. Leonard
  • A. Romanyuk
  • T. Hirai
  • G. Pintsuk
  • U. Breuer
  • A. Scholl

Organisaatiot

  • Lawrence Livermore National Laboratory
  • Jülich Research Centre
  • University of California at San Diego
  • University of Basel
  • University of Toronto
  • General Atomics
  • Sandia National Laboratories

Kuvaus

Mirrors will be used in ITER in all optical diagnostic systems observing the plasma radiation in the ultraviolet, visible and infrared ranges. Diagnostic mirrors in ITER will suffer from electromagnetic radiation, energetic particles and neutron irradiation. Erosion due to impact of fast neutrals from plasma and deposition of plasma impurities may significantly degrade optical and polarization characteristics of mirrors influencing the overall performance of the respective diagnostics. Therefore, maintaining the best possible performance of mirrors is of the crucial importance for the ITER optical diagnostics. Mirrors in ITER divertor are expected to suffer from deposition of impurities. The dedicated experiment in a tokamak divertor was needed to address this issue. Investigations with molybdenum diagnostic mirrors were made in DIII-D divertor. Mirror samples were exposed at different temperatures in the private flux region to a series of ELMy H-mode discharges with partially detached divertor plasmas. An increase of temperature of mirrors during the exposure generally led to the mitigation of carbon deposition, primarily due to temperature-enhanced chemical erosion of carbon layers by D atoms. Finally, for the mirrors exposed at the temperature of ∼160 °C neither carbon deposition nor degradation of optical properties was detected.

Yksityiskohdat

AlkuperäiskieliEnglanti
Sivut79-89
Sivumäärä11
JulkaisuFusion Engineering and Design
Vuosikerta83
Numero1
TilaJulkaistu - tammikuuta 2008
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

ID: 4085170