ITER-like PAM launcher for Tore Supraʹs LHCD system

In the frame of the Tore Supra Composants d’Injection de Matière et d’Énergie Stationnaire (CIMES) Project, consisting in particle fuelling via a pellet injector and in energy powering using Lower-Hybrid Current Drive (LHCD) for pulses lasting 1000 s, complemented by the transmitter refurbishing, a new launcher, based on the Passive-Active Multijunction (PAM) concept already proposed for ITER, has been developed and is currently under realisation. It was designed for a power injection capability of 2.7 MW CW at 3.7 GHz, a power density of 25 MW/m2, to radiate a power spectrum peaked at N// = 1.7 with a maximum power directivity near the electron cut-off density and with very good coupling properties on a wide range of electron densities. In this paper, an overall description of the antenna as well as the foreseen manufacturing and assembling processes are given, followed by the results from studies and optimisations of its RF components, by a stress analysis of its thermo-mechanical behaviour, taking into account the plasma radiated flux at the mouth and the RF losses, and complemented with additional mechanical stresses due to the combined action of the eddy current induced in the launcher by disruptions and the residual toroidal magnetic field.