TY - JOUR
T1 - Quasi-optical polarizer system for ECHCD experiments in the QUEST
AU - Fukuyama, M.
AU - Idei, H.
AU - Tsujimura, T. I.
AU - Kubo, S.
AU - Kobayashi, S.
AU - Yunoki, M.
AU - Onchi, T.
AU - Ikezoe, R.
N1 - Funding Information:
This work was performed under the auspices and support of the NIFS Collaboration Research Programs under Grants NIFS13KUTR085 and NIFS17KUTR128 . This research was partially supported by Grant-in-Aid for Scientific Research (B) (JSPS KAKENHI Grant Number JP1504231)
PY - 2019/9
Y1 - 2019/9
N2 - A new transmission line from 28 GHz gyrotron to QUEST spherical tokamak (ST) has been developed for the highly efficient electron cyclotron heating and current drive (ECHCD) experiments. The ECHCD effect depends on the incident mode or polarization states of the injected beam. Although two corrugated-polarizer miter bends were developed and assembled to transmission line in the QUEST, arcing events were frequently detected at the polarizer miter bend when the high-power millimeter-wave were transmitted. A new quasi-optical (QO) concept for the polarizer system composed of two corrugated plate and a QO mirror was proposed to avoid the arcing at polarizer. The QO mirror was designed for coupling of input and output HE11 modes at the polarizer, its coupling property is discussed with Kirchhoff integral. Polarization-setting performance of the developed QO polarizer was examined in a low-power test system, and is discussed with grating-polarizer calculation.
AB - A new transmission line from 28 GHz gyrotron to QUEST spherical tokamak (ST) has been developed for the highly efficient electron cyclotron heating and current drive (ECHCD) experiments. The ECHCD effect depends on the incident mode or polarization states of the injected beam. Although two corrugated-polarizer miter bends were developed and assembled to transmission line in the QUEST, arcing events were frequently detected at the polarizer miter bend when the high-power millimeter-wave were transmitted. A new quasi-optical (QO) concept for the polarizer system composed of two corrugated plate and a QO mirror was proposed to avoid the arcing at polarizer. The QO mirror was designed for coupling of input and output HE11 modes at the polarizer, its coupling property is discussed with Kirchhoff integral. Polarization-setting performance of the developed QO polarizer was examined in a low-power test system, and is discussed with grating-polarizer calculation.
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U2 - 10.1016/j.fusengdes.2019.02.099
DO - 10.1016/j.fusengdes.2019.02.099
M3 - Article
AN - SCOPUS:85063761479
SN - 0920-3796
VL - 146
SP - 1437
EP - 1440
JO - Fusion Engineering and Design
JF - Fusion Engineering and Design
ER -