Engineering design and analysis of the Alcator C-MOD two-strap ICRF antenna

ICRF (ion cyclotron range of frequencies) fast wave heating with up to 8 MW of RF power at 80 MHz is planned on the Alcator C-MOD tokamak (R=0.665 m, a=0.21 m, k≲1.8, B⩽9 T, I⩽3 MA). High power heating experiments will be carried out using two sets of two-strap antennas. Engineering aspects of antenna design and results of analyses are presented. The most important consideration was mechanical integrity against very large disruption loads expected in Alcator C-Mod. Thermal analyses indicate that for a transmitted power of 2 MW the antenna can be operated without active cooling for the planned lower hybrid current driven operation of up to 10 s duration