Gross and net erosion of tungsten in the outer strike-point region of ASDEX Upgrade

Research output: Contribution to journalArticle

Researchers

  • ASDEX Upgrade Team

Research units

  • Max-Planck-Institut für Plasmaphysik
  • Technische Universität München
  • VTT Technical Research Centre of Finland

Abstract

We have investigated net and gross erosion of W in the outer strike-point (OSP) region of ASDEX Upgrade with the help of marker probes during low-density/high-temperature L-mode discharges. Post mortem analyses indicate net-erosion rates of 0.04-0.13 nm s-1, with the highest rates measured close to the OSP. Re-deposition was some 30-40% of gross erosion, which is lower than what has earlier been obtained spectroscopically (∼50-60%), possibly due to the special plasma conditions of our experiment and intense flux of W atoms originating from the main chamber. Gross erosion was also estimated by passive emission spectroscopy, and around the OSP the results matched with post mortem data. However, the spectroscopic erosion profile in the poloidal direction was much steeper than the post mortem one. Preliminary ERO simulations have predicted net erosion of the same order of magnitude as experimental results but reproducing the poloidal erosion/re-deposition profiles requires further work.

Details

Original languageEnglish
Pages (from-to)1-6
Number of pages6
JournalPhysica Scripta
Volume2016
Issue numberT167
Publication statusPublished - 12 Jan 2016
MoE publication typeA1 Journal article-refereed
EventInternational Conference on Plasma-Facing Materials and Components for Fusion Applications - Aix-en-Provence, France
Duration: 18 May 201522 May 2015
Conference number: 15

    Research areas

  • ASDEX Upgrade, erosion, re-deposition, tokamak, tungsten

ID: 18203567