Basic concepts and implementation strategy of the plasma discharge command sequencer for FTU Tokamak

Abstract The plasma discharge phase of Frascati Tokamak Upgrade (FTU) is driven by the dedicated system FSC (Fast Sequence Control), which has been developed in order to send all the necessary commands to the different power plants, feeding the toroidal and poloidal coils during the plasma discharge, meanwhile controlling the correct outcome and recording all the events with time resolution of the order of 20 μs. In case of incorrect execution of the sequence the system is able to safely shutdown the plants and the plasma pulse. The FSC system has been recently upgraded porting it to an up to date off the shelf hardware platform, taking thus the opportunity to revise and update the basic concepts of the system and to increase its flexibility in view of possible applications to future fusion machines. The system is equipped with an integrated configurator and a custom sequence programming language allowing the user to program the sequences by linking the actuation times of the commands and of the state verifications each other or to global time parameters. A dedicated compilator performs the compilation of the sequence generating the binary files that are then loaded and implemented by the FSC hardware.