Comparison of JET inner wall erosion in the first three ITER-like wall campaigns

Le résumé fourni par la source

The net erosion of material from recessed areas of the JET main chamber inner wall during the first three ITER-like wall (JET-ILW) campaigns was studied using long-term samples with Be and W marker layers. The samples were analyzed using elastic backscattering spectrometry (EBS) before and after each campaign. It was found that the erosion for both Be and W was roughly homogeneously distributed in both toroidal and poloidal directions, possibly with a small maximum near the middle of the inner wall and a minimum near the bottom of the wall, as well as several toroidal distribution features. The net erosion rate of Be decreased by a factor of two between the first and the second JET-ILW campaigns, and remained unchanged during the third JET-ILW campaign. Three possible explanations are presented: a campaign to test the power handling capability of the limiter in ILW1, a change in incident particle energy distribution, and a change in limiter to divertor discharge time ratio. The net erosion rate of W remained almost unchanged through the first two JET-ILW campaigns. In the third JET-ILW campaign the net erosion rate of W from the inner wall was about 1.6 times higher than previously observed, indicating a change in the energy spectrum of particles eroding the inner wall, and the occasional addition of Kr and Xe to the fuelling.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.