The TCV ECRH-ECCD system is divided into 3 clusters of 3 gyrotrons each. Each cluster is powered separately by its own Regulated High Voltage Power Supply (RHVPS).
Each RHPVS (85kV, 80A; duty-cycle: 1%; switch-off time: 1μs) uses the so called pulse step modulator technology where 2×40 solid-state modules (1.05kV each) are connected in series. Each module output is controlled by solid state IGBT elements (Insulated Gated Bipolar Transistor, switching frequency: 5kHz).
Energy is supplied by the electric grid (20kV) for conditioning purposes (e.g., gyrotron testing) or by the TCV motor generator during a plasma discharge (pulsed operation: 2s every 10 min).
Cooling and Vacuum Systems
The TCV ECRH-ECCD system generates a considerable amount of waste heat during its operation which is removed by a water cooling system.
Water is pumped through cooling circuits in either gyrotron components (e.g, collector, cavity and quasi-optical system) or in the loads into which the microwave beams are dumped (during gyrotron conditioning, or TCV operation when a connected gyrotron is not required for a specific discharge).
In the TCV ECRH-ECCD system, the transmission lines, gyrotrons, superconducting magnets (isolation), loads and MOUs all need to operate in a vacuum atmosphere. For this purpose vacuum ion, sorption, rotary vane and turbo pumps are used.