Third and fourth harmonics of electromagnetic emissions by a weak beam in a solar wind plasma with random density fluctuations by C. Krafft

2022-11-22 145 views

Electromagnetic emissions at the third harmonic of the plasma frequency $\omega _{p}$ have been reported during the occurrence of type II and type III solar radio bursts (e.g. Zlotnik 1978, Zlotnik et al. 1998, Cairns; 1986), even if rarely and sometimes controversially. Recently the Wind spacecraft detected several events exhibiting third harmonic emissions in interplanetary type III bursts observed locally near 1 AU (Reiner and MacDowald; 2019). For the first […]

Fundamental electromagnetic emissions by a weak electron beam in solar wind plasmas with density fluctuations
by C. Krafft and P. Savoini

2022-04-05 150 views

Solar radio bursts of Type III were currently observed since decades in the interplanetary space (Reid and Ratcliffe, 2014). They result from a series of successive processes arising in solar coronal and wind plasmas where Langmuir wave turbulence is radiated by electron beams generated during flares, leading ultimately to the emission of electromagnetic waves at the fundamental plasma frequency $\omega _{p}$ and its second harmonic. The Letter by Krafft and […]

Particle-in-cell simulation of plasma emission in solar radio bursts
by T. M. Li et al.

2021-12-21 185 views

Solar radio radiation is one of the most sensitive emissions during solar eruptions, where type III radio bursts can provide clues for electron acceleration and propagation. Type III radio bursts are widely accepted to result from the plasma emission, which is observationally supported by the presence of Langmuir waves, and excited electromagnetic waves at fundamental and harmonic frequencies from the nonlinear wave coupling (Ginzburg & Zhelezniakov 1958). Such a mechanism […]

Electromagnetic Emission Produced by Three-wave Interactions in a Plasma with Continuously Injected Counterstreaming Electron Beams
by Vladimir Annenkov and Igor Timofeev

2021-01-19 234 views

Weakly turbulent processes of three-wave interactions between Langmuir and electromagnetic waves in plasma with unstable electron flows are believed to be the main cause of type II and III solar radio emissions. The narrow band of type II bursts requires assuming that this radiation is generated in some local regions of shock fronts traveling in the solar corona, where the specific conditions for the enhancement of electromagnetic emissions near the […]

Solar plasma radio emission and inertial Alfvén turbulence
by O. Lyubchyk et al.*

2017-09-26 559 views

We study the influence of kinetic-scale Alfvénic turbulence on the generation of plasma radio emission in the solar coronal regions where the plasma/magnetic pressure ratio $\beta $ is smaller than the electron/ion mass ratio $m_{e}/m_{i}$. The present study is motivated by the phenomenon of solar type I radio storms associated with the strong magnetic field of active regions. The measured brightness temperature of the type I storms can be up […]