RF transmission properties and its application research of coaxial-line-like waveguide with cutoff frequency

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K04726
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: General applied physics
• Research Institution: National Institutes for Quantum and Radiological Science and Technology (2016-2017); Japan Atomic Energy Agency (2015)
• Principal Investigator: Sawamura Masaru 国立研究開発法人量子科学技術研究開発機構, 高崎量子応用研究所 東海量子ビーム応用研究センター, 上席研究員(定常) (30354905)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 超伝導加速器 / 高調波 / 導波管 / ＨＯＭカップラー

Outline of Final Research Achievements

I proposed a C-shaped waveguide which structure had the plate connecting the inner and outer conductors of the coaxial waveguides. The C-shaped waveguide has characteristics of 1) cutoff frequency, 2) easy conversion to the coaxial line, and 3) easy cooling of inner conductor. RF properties of the C-shaped waveguide were investigated and it was applied to the HOM coupler to attenuate the higher-order modes (HOMs) of the superconducting accelerator. The measured results with the C-shaped waveguide model agreed with the calculated results with the RF simulation code. The HOM coupler model was attached to three types of cavities to investigate to HOM damping. The good HOM coupler properties were confirmed of little influence on the acceleration mode and sufficient damping of HOMs.

Free Research Field

加速器工学