The lower hybrid current drive system for ITER: progress on the route of the new launchers

The design of a Lower Hybrid Waves (LHW) system for ITER EDA is based on the robust concept of the passive active multijunction (PAM) which associates a good coupling of the slow wave with an efficient cooling of the grill mouth. The PAM is fed by an oversized section (hyperguide) exited by several mode converters which ensure the poloidal sharing of the RP power. Specific components, such as the mode converter and hyperguide have now been successfully tested at high power and long pulse duration (up to 1000 s on test bed). The 50 MW required to cover the envisioned scenarios, can be coupled by two launchers located in two ports of the machine. The working incident power density is 23 MW/m/sup 2/ which is routinely achieved in present experiments at 3.7 GHz.