Langmuir waves – Community of European Solar Radio Astronomers

Solar electron beam velocities that grow Langmuir waves in the inner heliosphere by C. Y. Lorfing et al.

2023-08-15 0 views

Solar accelerated electron beams interact with the background plasma of the solar wind to locally generate Langmuir waves and subsequently produce radio emission (Ginzburg and Zhelezniakov 1958). Numerous observations at different distances from the Sun by spacecrafts like Solar Orbiter (0.5AU) and ACE (1AU) show different energy ranges of electrons interacting with the plasma to produce Langmuir oscillations. At 0.5AU, non-thermal electrons in the deca-keV range arrive co-temporal to the […]

Langmuir-Slow Extraordinary Mode Magnetic Signature Observations with Parker Solar Probe
by A. Larosa et al

2022-05-03 142 views

Langmuir-Slow extraordinary mode (L-SE) waves have been routinely observed in the Solar wind and in Earth’s electron foreshock since the early age of the space exploration. They are intimately connected to the plasma emission mechanism for the type III and type II radio emissions. In fact, the generally accepted scenario is that L-SE waves are mode-converted to freely propagating electromagnetic emission at the plasma frequency. However, the details of the […]

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 […]

Langmuir wave motion observed in the most intense radio sources in the sky
by H. Reid and E. Kontar

2021-08-31 403 views

The Sun routinely produces energetic electrons in its outer atmosphere that subsequently travel through interplanetary space. These electron beams generate Langmuir waves in the background plasma, producing type III radio bursts that are the brightest radio sources in the sky (Suzuki & Dulk, 1985). These solar radio bursts also provide a unique opportunity to understand particle acceleration and transport which is important for our prediction of extreme space weather events […]

Large-scale simulations of Langmuir Wave Distributions Induced by Electron Beams
by H. Reid and E. Kontar

2017-02-14 810 views

Langmuir waves that generate type III radio bursts are excited by high-energy electron beams streaming out from the corona through interplanetary space. Despite a smooth temporal distribution of electrons, the Langmuir waves are measured to occur in discrete clumps, commonly attributed to the turbulent nature of the solar wind electron density (e.g. Smith and Sime 1979, Melrose et al 1986). But how do fluctuations in the background plasma shape the […]

Acceleration of electrons in the solar wind by Langmuir waves produced by a decay cascade
by Catherine Krafft and Alexander Volokitin

2016-12-13 792 views

It was recently reported that a significant part of the Langmuir waveforms observed by the STEREO satellite (Graham and Cairns, 2013) during type III solar radio bursts are likely consistent with the occurrence of electrostatic decay instabilities, when a Langmuir wave $\mathcal{L}$ resonantly interacts with another Langmuir wave $\mathcal{L}^{\prime}$ and an ion sound wave $\mathcal{S}^{\prime}$ through the decay channel $\mathcal{L} \rightarrow\mathcal{L}^{\prime}+\mathcal{S}^{\prime}$. Usually such wave-wave interactions occur in regions of the […]