Disruption study advances in the JET metallic wall

Recently, the JET disruption mitigation system has been augmented with new disruption mitigation valve making the disruption mitigation system (DMS) of JET very close to the future ITER set-up. Experiments have focussed on optimizing the operating parameters of the DMV in JET plasmas and studying the disruption asymmetries. It is found that each DMV can mitigate the JET vessel vertical reaction force by ~40% on the machine with respect to vertical displacement (VDE) tests and an optimum impurity injection of 1022 atoms can be found. In addition, a minimum radiative gas quantity can also be determined experimentally independently from the plasma current for ensuring efficient mitigation. The use of two valves in opposite octants has successfully been used to reduce the radiation asymmetry. Progress has also been made on disruption prediction focussing on predictors that minimizes the required training or using physics based predictors for use in JET scenarios.