Millimeter fast directional switch system for the NTM suppression experiments on JT-60SA

Idei, Hiroshi*; Moriyama, Shinichi; Kobayashi, Takayuki; Isayama, Akihiko; Sakaguchi, Masatsugu*; Kasparek, W.*

A FAst DIrectional Switch (FADIS) performance based on steep slope in a diplexer function has been considered for dual-frequency (dual-f) applications to switch the transmission line with small frequency control. A diplexer of a FADIS using a Square Corrugated Waveguide (SCW) splitter was designed as one of most attractive candidates for the dual-f operation on the JT-60SA system. The splitter performance was a key issue for the dual-f operation, and extended operation regions in splitter operations have been considered using mode contents analyses based on matching coefficient evaluation. Some operational branches with high matching coefficients ( 0.9) were found, and new operation parameters were proposed for the dual-f application. Radiation pattern distributions from the SCW splitter were defined very well with no serious side lobes. Double loop resonant ring system has been proposed with the SCW splitter for the dual-f operation.