Surface analysis of tiles and samples exposed to the first JET campaigns with the ITER-Like Wall

TL;DR

This study analyzes tiles from JET's first campaigns with the ITER-like Wall, revealing significantly reduced beryllium deposition and deuterium retention compared to previous carbon campaigns, using advanced surface analysis techniques.

Contribution

It provides the first post-mortem analysis of tiles after JET's ILW campaigns, quantifying material deposition and retention with detailed surface analysis.

Findings

Beryllium films of 10-20 microns were found on top of Tile 1.

Very thin films (<1 micron) were present in shadowed areas.

Total Be deposition was about nine times less than in previous carbon campaigns.

Abstract

This paper reports on the first post-mortem analyses of tiles removed from JET after the first campaigns with the ITER-like Wall (ILW) during 2011-2 [1]. Tiles from the divertor have been analysed by the Ion Beam Analysis (IBA) techniques Rutherford Backscattering Spectroscopy (RBS) and Nuclear Reaction Analysis (NRA) and by Secondary Ion Mass Spectrometry (SIMS) to determine the amount of beryllium deposition and deuterium retention in the tiles exposed to the scrape-off layer. Films 10-20 microns thick were present at the top of Tile 1, but only very thin films (<1 micron) were found in the shadowed areas and on other divertor tiles. The total amount of Be found in the divertor following the ILW campaign was a factor of ~9 less that the material deposited in the 2007-9 carbon campaign, after allowing for the longer operations in 2007-9.