@article{ade5569c47034a05ab3ef06a7e94fcb5,
title = "W-band millimeter-wave back-scattering system for high wavenumber turbulence measurements in LHD",
abstract = "A 90 GHz W-band millimeter-wave back-scattering system is designed and installed for measuring electron scale turbulence (k⊥ρs ∼40). A metal lens relay antenna is used for in-vessel beam focusing, and a beam diameter of less than 40 mm is achieved in the plasma core region. This antenna can be steered at an angle of 159° ± 6°, which almost covers the plasma radius. The estimated size of the scattering volume is ∼105 mm at the edge and 135 mm at the core, respectively. A 60 m corrugated waveguide is used to achieve a low transmission loss of ∼8 dB. A heterodyne detection system for millimeter-wave circuits with probing power modulation can distinguish the scattered signal from background noise. ",
author = "T. Tokuzawa and K. Tanaka and T. Tsujimura and S. Kubo and M. Emoto and S. Inagaki and K. Ida and M. Yoshinuma and Watanabe, {K. Y.} and H. Tsuchiya and A. Ejiri and T. Saito and K. Yamamoto",
note = "Funding Information: The authors would like to thank the technical staff of LHD for their support. The authors also would like to thank Mrs. K. Takehara and T. Ito for their support of metallic lens production. This work was partially supported, in part, by KAK-ENHI (Grant Nos. 19H01880, 17K18773, 17H01368, 15H02335, and 15H02336), by a budgetary grant-in-aid from the NIFS LHD project under the auspices of the NIFS Collaboration Research Program (Grant Nos. ULPP027 and KLPH024), by the NINS program for cross-disciplinary study (Grant Nos. 01311802 and 01311903), and by the collaboration programs of the RIAM of Kyushu University and FIR-UF of Fukui University. Additional support was provided by Japan/U.S. Cooperation in Fusion Research and Development. Publisher Copyright: {\textcopyright} 2021 Author(s).",
year = "2021",
month = apr,
day = "1",
doi = "10.1063/5.0043474",
language = "English",
volume = "92",
journal = "Review of Scientific Instruments",
issn = "0034-6748",
publisher = "American Institute of Physics Publising LLC",
number = "4",
}