Investigation of probe surfaces after ion cyclotron wall conditioning in ASDEX Upgrade
(English)Manuscript (preprint) (Other academic)
For the first time, material analysis techniques have been applied to study the effect of ion cyclotron wall conditioning (ICWC) on probe surfaces in a metal-wall machine. ICWC is a technique envisaged to contribute to the removal of fuel and impurities from the first wall of ITER. The objective of this work was to assess impurity migration under the ICWC operation. Tungsten probes were exposed in ASDEX Upgrade to discharges in helium. After wall conditioning, the probes were covered with a co-deposited layer containing D, B, C, N, O and relatively high amount of He on virgin W substrates. The concentration ratio He/C+B was 0.7. The formation of the co-deposited layer indicates that a fraction of the impurities desorbed from the wall under ICWC operation are transported by plasma and deposited away from their original location.
ICWC, Erosion-deposition, fuel removal, ion beam analysis, ASDEX Upgrade
Research subject Physics
IdentifiersURN: urn:nbn:se:kth:diva-190898OAI: oai:DiVA.org:kth-190898DiVA: diva2:953636
QC 201608192016-08-182016-08-182016-09-02Bibliographically approved