EFDA-JET-CP(10)01/04
Feasibility of an ECRH System for JET: Transmission Lines & Windows
Quasi-Optical (QO) and Evacuated WaveGuide (EWG) Transmission Lines (TL) have been analyzed as possible solutions to transfer the power from the gyrotrons to the launcher. The EWG solution has been chosen as the reference TL solution due to the achieved space saving, its flexibility and its ITER relevance. The proposed EWG routing is compatible with the use of standard components, a small number of mitre bends and <5% of expected attenuation. Concerning the vacuum window, the only material currently available giving the power/pulse length combination is based on the use of disks in synthetic diamond (CVD). This choice gives the opportunity to adopt the window design proposed for the ITER project. A technical solution exploiting two separate single disk windows rather than a double window has been analyzed in order to fulfill safety requirements and to take into account problems arising in transmitting high power.