Using APCS for Plasma Vertical Control at TCV

Early tokamaks with circular cross-section plasmas were vertically stable in nature and no problems were reported on the control of the vertical position. However, the concept of vertically elongated plasma cross-section, with benefits to the energy confinement time, led to vertical instabilities. To overcome this problem, complex closed feedback loop control systems with a vertical position measurement, signal processing, control algorithm, power supplies and active actuating coils are used.