Observation of spectral composition and polarization of sub-terahertz emission from dense plasma during relativistic electron beam–plasma interaction
- Budker Institute of Nuclear Physics, 11 Lavrentiev Ave., Novosibirsk 630090 (Russian Federation)
The paper presents results of measurements of sub-terahertz electromagnetic emission from magnetized plasma during injection of a powerful relativistic electron beam of microsecond duration in plasma with the density of 3 × 10{sup 14 }cm{sup −3}. It was found that the spectrum of the radiation concentrated in three distinct regions with high level of spectral power density. The first region is located near f{sub 1} = 100 GHz; the second one is in the vicinity of 190 GHz, and the third region is in the frequency interval f{sub 3} = 280–340 GHz. Polarization vectors of the emission in the first and third regions (f{sub 1} and f{sub 3}) are directed mainly perpendicular to the magnetic field in the plasma. At the same time, the polarization of the radiation in the vicinity of f{sub 2} = 190 GHz is parallel to the magnetic field. The most likely mechanism of electromagnetic wave generation in the frequency regions f{sub 1} and f{sub 2} is the linear conversion of the plasma oscillations into the electromagnetic waves on strong gradients of the plasma density. The third region is situated in the vicinity of second harmonic of electron plasma frequency, and we explain this emission by the coalescence of the upper-hybrid oscillations at high level turbulence in plasma.
- OSTI ID:
- 22303756
- Journal Information:
- Physics of Plasmas, Vol. 21, Issue 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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