Empirical error field control at JET in preparation of ITER start-up

This work reports on error field identification and control studies carried out at JET and insights on the development of the empirical EF controller for ITER. The empirical EF controller has been included in the JET real-time central controller following the execution of the non-disruptive compass scan method (Paz-Soldan C. et al., Nuclear Fusion 62 (2022) 126007), which allowed the identification of the EF source and the currents for error field compensation. When testing the empirical EF controller, born locked n = 1 modes have been observed to spin-up and a lower density regime has been explored in the 1.8 MA plasma current, 2.1 T toroidal magnetic field scenario than otherwise achievable. These experimental results demonstrate the benefits of EF correction. In preparation of EF correction studies in ITER, the empirical EF controller for ITER has been developed and integrated in the plasma control system database.