Development of FPGA controlled diagnostics on the MAST fusion reactor

Abstract

Field Programmable Gate Array technology (FPGA) is very useful for implementing high performance digital signal processing algorithms, data acquisition and real-time control on nuclear fusion devices. This thesis presents the work done using FPGAs to develop powerful diagnostics. This has been achieved by developing embedded Linux and running it on the FPGA to enhance diagnostic capabilities such as remote management, PLC communications over the ModBus protocol and UDP based ethernet streaming. A closed loop real-time feedback prototype has been developed for combining laser beams onto a single beam path, for improving overall repetition rates of Thomson Scattering systems used for plasma electron temperature and density radial profile measurements. A controllable frequency sweep generator is used to drive the Toroidal Alfven Eigenmode (TAE) antenna system and results are presented indicating successful TAE resonance detection. A fast data acquisition system has been developed for the Electron Bernstein Wave (EBW) Synthetic Aperture Microwave Imaging system and an active probing microwave source where the FPGA clock rate has been pushed to the maximum. Propagation delays on the order of 2 nanoseconds in the FPGA have been finely tuned with careful placement of FPGA logic using a custom logic placement tool. Intensity interferometry results are presented on the EBW system with a suggestion for phase insensitive pitch angle measurement.