  The aim of the JET ITER-like Wall Project was to provide JET with the plasma
facing material combination now selected for the DT phase of ITER (bulk
beryllium main chamber limiters and a full tungsten divertor) and, in
conjunction with the upgraded neutral beam heating system, to achieve ITER
relevant conditions. The design of the bulk Be plasma facing components had to
be compatible with increased heating power and pulse length, as well as to
reuse the existing tile supports originally designed to cope with disruption
loads from carbon based tiles and be installed by remote handling. Risk
reduction measures (prototypes, jigs, etc) were implemented to maximize
efficiency during the shutdown. However, a large number of clashes with
existing components not fully captured by the configuration model occurred.
Restarting the plasma on the ITER-like Wall proved much easier than for the
carbon wall and no deconditioning by disruptions was observed. Disruptions have
been more threatening than expected due to the reduced radiative losses
compared to carbon, leaving most of the plasma magnetic energy to be conducted
to the wall and requiring routine disruption mitigation. The main chamber power
handling has achieved and possibly exceeded the design targets.
