The C-2W real time inference and plasma control system

As Field Reversed Configuration (FRC) discharges in C-2W (also known as Norman) last longer than the time constant of the conductive structures external to the plasma, feedback control systems become necessary to maintain the FRC plasma well centered inside the confining vessel. The function of the C-2W Plasma Control System (PCS) is both to provide high bandwidth (2.5 MHz) data acquisition of about 400 magnetic signals, and low bandwidth feedback control (40 kHz) of FRC plasma shape and position. In addition, the system capacity allows for future expansion for control of kinetic plasma variables. PCS is a distributed control system built from a set of data acquisition modules and control units from Speedgoat, programmed using Matlab scripts and Simulink models. This allows for fast prototyping and testing of observers and control algorithms, a useful feature for plasma control systems research. Examples of these are a low latency Bayesian observer for plasma equilibrium and advanced control algorithms for plasma shape, position and stability. First operational experience with the system is presented and discussed.