Optimized design of polarizers with low ohmic loss and any polarization state for the 28 GHz QUEST ECH/ECCD system
| Autor: | Hiroshi Idei, Shin Kubo, Sakuji Kobayashi, Toru Ii Tsujimura |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Materials science
Polarizer Transmission loss Nanotechnology Spherical tokamak 01 natural sciences 010305 fluids & plasmas law.invention Optics Transmission line law 0103 physical sciences Surface roughness General Materials Science Ohmic contact Civil and Structural Engineering 010302 applied physics Polarization rotator business.industry Mechanical Engineering Millimeter-wave transmission Miter bend Electron cyclotron heating and current drive Polarization (waves) Nuclear Energy and Engineering business |
| Zdroj: | Toru Ii Tsujimura, Hiroshi Idei, Shin Kubo, Sakuji Kobayashi, Optimized design of polarizers with low ohmic loss and any polarization state for the 28GHz QUEST ECH/ECCD system, Fusion Engineering and Design, Volume 114, 2017, Pages 97-101 |
| ISSN: | 0920-3796 |
| Popis: | In a high-power long-pulse millimeter-wave transmission line for electron cyclotron heating and current drive (ECH/ECCD), the ohmic loss on the grooved mirror surface of polarizers is one of the important issues for reducing the transmission loss. In this paper, the ohmic loss on the mirror surface is evaluated in simulated real-scale polarizer miter bends for different groove parameters under a linearly-polarized incident wave excitation. The polarizers with low ohmic loss are optimally designed for a new 28 GHz transmission line on the QUEST spherical tokamak. The calculated optimum ohmic loss is restricted to only less than 1.5 times as large as the theoretical loss for a copper flat mirror at room temperature. The copper rounded-rectangular grooves of the polarizers were relatively easy to make smooth in mechanical machining and the resultant surface roughness was not more than 0.15 μm, which is only 0.38 times as large as the skin depth. The combination of the designed elliptical polarizer and the polarization rotator can also realize any polarization state of the reflected wave. |
| Databáze: | OpenAIRE |
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