Study of the Design and Assembly of a High Harmonic Fast Wave Antenna for an LAPD

Abstract

The simulation survey of TAE Technologies has demonstrated that high harmonic fast wave (HHFW) heating is a promising method for core electron heating of FRC plasma. This study mainly describes the HHFW antenna mechanical design and assembly on the basis of the results of electromagnetic simulations performed by Oak Ridge National Laboratory (ORNL), the available port dimensions, and antenna installation position of the LAPD. Compared to the original scheme, this antenna is also optimized in the design. It is found that the E field distribution of optimized antenna becomes even, and the maximum electric field decreases by approximately 14%. The current on the antenna box and FS is reduced after optimization, whereas the maximum J density decreases from 53.3 kA to 14.5 kA. The reflection performance of the port at 30 MHz is also improved after the structural optimization; The k// spectrum distribution is sharper at the monopole phase (0, 0, 0, 0) and dipole phase (0, π, 0, π) and (0, 90, 270,180) than other phases. The optimized antenna can obtain a maximum |k//| spectrum, which peaks about |k//| = 30 m−1 at the dipole phase (0, π, 0, π). The analysis results and assembly strategy can provide useful reference and guidance for the study of HHFW antenna design and fabrication in LAPD or other magnetic confined fusion devices.