Progress of ITER equatorial electron cyclotron launcher design for physics optimization and toward final design

The design of the equatorial electron cyclotron (EC) launcher has advanced toward a more reliable and manufacturable final design. The modification to quasi-optical layout of the millimeter wave transmission line leads to the launcher design being reliable and more realistic toward the final design and the cost reduction. It is proposed that one of three beam rows of the launcher is flipped so that the EC power enables to contribute the counter-EC current drive based on the ITER physics requirement. In addition, a poloidal beam tilt angle of 5° has been introduced in the top and bottom beam row so that all beams can access from on axis to near mid-radius. These design modifications render the EC system more flexible to adapt the needs of advanced ITER physics experiments. It is preliminarily estimated that the nuclear shielding capability of the present modified design satisfies the neutron flux criterion, but the shut down dose rate of γ-ray is slightly higher than the criterion.