Electrical Design of an ICRF System for Ignitor
Abstract
A system of 6 antennae is designed for ion cyclotron resonance heating (ICRH) in Ignitor. The coupling properties of each antenna are calculated by using a two-dimensional slab model to obtain the parameters necessary to model the current strap as a trasmission line then using the calculated current profile in a three-dimensional simulation (the codes have been developed at ORNL). The antenna consists of 4 loop (straps) to form a 2×2 poloidal and toroidal phased array; in our proposal each strap is fed by a coaxial cable, an adapter and a RF power generator. The power spectrum of the radiated parallel index is optimized for out-of-phasing in order to obtain a high heating efficiency and a high loading resistance. The predicted loading and "effective" resistance is sufficient for ICRH experiments with 4.0 MW of power injected in the plasma by each antenna as long as the distance between the Faraday shield and plasma separatrix surface is smaller than 4.0 cm. The maximum RF voltage in the system is 50.0 kV which is limited by generator power and coaxial cable dimensions. The development of a self-consistent integral-equation code is presently under way to analyze geometry effects on the antenna performances. Sponsored by ENEA, CNR, and ASP of Italy, and by the US DoE
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- November 1996
- Bibcode:
- 1996APS..DPP..5Q09M