JET ILA full array and polychromatic operation

The JET ILA is an Ion Cyclotron Resonance Heating (ICRH) antenna composed of four resonant double loops (RDLs) arranged in a 2 toroidal by poloidal compact array. It has been operated range frequencies from 29 to 51 MHz, but mostly on half Some full array pulses were achieved without all control implemented. All algorithms (first and second stage matching, phasing, totalling 22 feedback loops) have now implemented recently allowed operate the at 33 MHz 42 up 4 MW. also for first time perform phase scan 37 with dipole phasing. Although operation proven reliable it unstable several occasions due high level mutual coupling between different RDLs inherent To decouple top bottom halves, tests successfully performed polychromatic – or dual frequency (operation around central frequency).