Double Langmuir frequency radiation due to transformation processes in turbulent plasma

Abstract

We investigate the transformation process of longitudinal Langmuir wave into the transverse electromagnetic wave in turbulent plasma subjected to an upper hybrid pump. The case, when upper hybrid pump wave decays into daughter and ion -sound waves is considered. The transformation of the Langmuir wave into electromagnetic one is considered as the possible mechanism of energy radiation from the plasma. It is shown that the frequency of such radiation is chosen to be near double electron Langmuir frequency 2ω pe . These results give us the possibility to explain the nature of radiation from the laboratory and cosmic plasmas (particularly, from the solar crown).

Influence of Inhomogeneity on Transformation and Radiation Processes in Plasma with Upper Hybrid Pump

“…are the frequencies and wave vectors of the incident and transformed waves, respectively; O is the solid angle; and ⟨︀ 2 ⟩︀ q,Δ is the correlator of electron density fluctuations at the combinational frequency Δ (the formula for this parameter can be found, e.g., in work [22]). The factor in formula (1) is determined by the known expression [11,24] and depends on the direction of the incident and transformed waves with respect to the magnetic field. Attention should also be paid to that the frequencies and wave vectors of the incident and transformed waves are mutually related by the energy and momentum conservation laws,…”

“…Various transformation processes in a magnetized turbulent plasma with low hybrid pumps were considered in works [22,23]. The transformation in a turbulent plasma with upper hybrid pump was studied in work [24]. The results obtained in the cited works made it possible to explain the mechanism of electromagnetic radiation emission from a plasma, in particular, the spontaneous radiation emission from Sun's corona at the double Langmuir frequency.…”