Characterization and heat flux testing of beryllium coatings on Inconel for JET ITER-like wall project

Abstract

In order to perform a fully integrated material test, JET has launched the ITER-like wall project with the aim of installing a full metal wall during the next major shutdown. The material foreseen for the main chamber wall is bulk Be at the limiters and Be coatings on inconel tiles elsewhere. R&D process comprises global characterization (structure, purity etc) of the evaporated films and testing of their performance under heat loads. The major results are (i) the layers have survived energy loads of 20 MJ m−2 which is significantly above the required level of 5–10 MJ m−2, (ii) melting limit of beryllium coating would be at the energy level of 30 MJ m−2, (iii) cyclic thermal load of 10 MJ m−2 for up to 50 cycles have not induced any noticeable damage such as flaking or detachment.