关键词: 等离子体填充/
金属光子晶体/
Cherenkov辐射/
慢波结构
English Abstract
Simulation of cherenkov radiation oscillation in a plasma-filled metallic photonic crystal
Fu Tao1,2,Ouyang Zheng-Biao1
1.Shenzhen Key Laboratory of Micro-Nano Photon Information Technology, THz Technical Research Center of Shenzhen University, College of Electronic Science and Technology, Shenzhen University, Shenzhen 518060, China;
2.Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
Fund Project:Project supported by the National Natural Science Foundation of China (Grant No. 61275043), the Young Scientists Fund of the National Natural Science Foundation of China (Grant Nos. 61501302, 61307048), and Shenzhen Bureau, China (Grant No. CXB201105050064A).Received Date:10 November 2015
Accepted Date:08 January 2016
Published Online:05 April 2016
Abstract:Plasma filling can significantly improve the efficiency and power of a vacuum device. In this paper, we first analyze the dispersion properties of a plasma-filled metal-photonic-crystal slow-wave structure (SWS), and then investigate the interaction procedure between a relativistic electron beam and the Cherenkov radiation in the plasma-filled metallic-photonic-crystal by the particle in cell method. We pay our attention to the influences of plasma density, cathode voltage, and guiding magnetic field on output frequency and power. The results show that the electric field strength in the SWS increases obviously at a fixed plasma density of 50 mTorr (1m mTorr=0.133 Pa). The device works at a stable single TM01 mode due to the good mode properties of the metal photonic crystal even if plasma is filled in it. The maximum value of Ez field along the z axis of the device increases from 46.34 MV/m without plasma to 79 MV/m with plasma. The value along the x axis increases from 136 MV/m without plasma to 185 MV/m with plasma. The working frequency (35.5 GHz) of the device, obtained from simulation, is consistent with the theoretical estimation (35.4 GHz). The power increases with the cathode voltage between 500 kV and 600 kV while the frequency increases only a little. When the magnetic field B increases, the output power first increases and then decreases. But the frequency is not affected due to the dispersion property. The output power of the device increases 20% when the air pressure increases from 0 to 100 mTorr. However, there is a pretty distribution of the field Ez along the angular direction only in an appropriate plasma density around 50 mTorr. According to the theory and simulation, the output power and efficiency can be improved in an appropriate range of plasma density. These results provide a basis for developing the plasma-filled vacuum devices.
Keywords: plasma-filled/
metal photonic crystal/
Cherenkov radiation/
slow-wave structure
