Progress in the high power CW klystron development for Tore Supra

One of the main Tore Supra (TS) objectives is to produce long and performing non-inductive discharges whose studies are crucial for the next step. The Lower Hybrid (LH) system is routinely used on TS to provide such discharges. The CIMES project will improve the TS LH power injection facilities leading to a transmitter power of 10 MW CW. klystron, TH2103C has been developed at Thales Electron Devices since November 2001. The specified RF output power is 620 kW CW on plasma (Voltage Standing Wave Ratio (VSWR) = 1.4) and 700 kW CW on matched load. Six klystrons have been successively manufactured and tested to define the good design. The last one was successfully tested on both TED and CEA test beds. It shows adequate margins of its design towards specifications. These margins ensure high reliability needed for long pulse operation (LPO) foreseen in the frame of the CIMES project. ocedure used to test the klystron and the safety interlocks carried out to avoid klystron defaults are detailed. The results obtained with prototype are presented and analyzed.