Design a high Q RF cavity for axion search system
Yi-Chieh Chang1*, Wei-Yuan Chiang1, Ching-Fang Chen2, Yuan-Hann Chang3
1Electrical Engineering, Ming Chi University of Technology, New Taipei, Taiwan
2Center of High-energy and High-field Physics, National Central University, Tao Yuan, Taiwan
3Physics, Academia Sinica, Taipei, Taiwan
* Presenter:Yi-Chieh Chang,
The main goal of this study is designing a system to search for axion-like dark matter in the mass range of μeV to meV. The two main parts of the system are a superconductor magnetic system (8 Tesla) and a RF cavity (5 GHz) that operated in cryogenic condition (~ 0.2 K). This study focuses on design RF cavity. To get higher sensitivity, the cavity must be with large volume and high-quality factor (Q). Since the axion conversion requires strong magnetic field inside, the material of cavity cannot be fully superconducting. The energy of a single photon at 5 GHz is 20.68 μeV, corresponding to 0.22K in temperature. This cavity is a single mode cavity. The quality factor of cavity is large then 15000. The fundamental mode of the RF cavity is TM₀₁₀ mode. To get large volume of cavity, the periodic structure is used to design the RF cavity. The modes-crossing problem and excitation effect are also discussed in this study.

Keywords: Radio Frequency Cavity, Single mode, Mode-crossing, Axion