Adaptive array technique for differential-phase reflectometry in QUEST

作者:Idei H*; Nagata K; Mishra K; Yamamoto M K; Itado T; Akimoto R; Hanada K; Zushi H
来源:Review of Scientific Instruments, 2014, 85(11): 11D842.
DOI:10.1063/1.4891710

摘要

A Phased Array Antenna (PAA) was considered as launching and receiving antennae in reflectometry to attain good directivity in its applied microwave range. A well-focused beam was obtained in a launching antenna application, and differential-phase evolution was properly measured by using a metal reflector plate in the proof-of-principle experiment at low power test facilities. Differential-phase evolution was also evaluated by using the PAA in the Q-shu University Experiment with Steady State Spherical Tokamak (QUEST). A beam-forming technique was applied in receiving phased-array antenna measurements. In the QUEST device that should be considered as a large oversized cavity, standing wave effect was significantly observed with perturbed phase evolution. A new approach using derivative of measured field on propagating wavenumber was proposed to eliminate the standing wave effect.

  • 出版日期2014-11