Control of tokamak plasmas: introduction to a special section

This paper provides an introduction to this issue's special section on the tokamak plasma control problems that have been identified. Since tokamak plasmas are high-order, nonlinear distributed systems with a large number of instabilities, there are many challenging control problems that must be solved before fusion power production becomes viable. As more advanced controllers are successfully brought online in working tokamaks, the benefits of sophisticated control methods are becoming widely recognized in the fusion community. This recognition and the urgent control needs of the planned multibillion dollar ITER tokamak make this an exciting time to be working on tokamak plasma control.