1. Terahertz radiation generated by electron-beam-driven plasma waves in a transverse external magnetic field.
- Author
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Yang, Shengpeng, Wang, Shaomeng, Wang, Zhanliang, Zhang, Ping, Xia, Yuxi, Tang, Changjian, and Gong, Yubin
- Subjects
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PLASMA waves , *MAGNETIC fields , *SUBMILLIMETER waves , *ELECTROMAGNETIC radiation , *RADIATION sources , *PLASMA frequencies , *CYCLOTRONS - Abstract
It is found that the plasma waves driven by an electron beam rotating in a magnetized overdense plasma can be converted into terahertz electromagnetic radiation by new mechanisms. According to the particle-in-cell simulation results, the radiation modes include a dominant extraordinary (X) mode at twice the plasma frequency 2 f p and a subordinate X mode at f p . The 2 f p radiation can be generated by the coupling of a beam mode and a scattered upper-hybrid (UH) mode, or by the coupling of a beam mode and a right-handed X mode. Here, the beam mode can be a UH mode or a left-handed X mode driven by the beam under the Cherenkov condition, and the right-handed X mode can be induced by high-order electron cyclotron maser instability. The f p radiation is the right- or left-handed fundamental X mode escaping from the plasma boundary. This study also shows that the breakdown of beam modulation is responsible for the radiation attenuation. The scheme proposed in this paper can be applied in high-power THz radiation sources and diagnosis of magnetized plasmas. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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