Resonance broadening due to particle scattering and mode coupling in the quasi‐linear relaxation of electron beams

Bian, N. H.; Kontar, Eduard P.; Ratcliffe, Heather

doi:10.1002/2013ja019664

Cited by 16 publications

(19 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore the resonance broadening effects due to waves' transformations on the density inhomogeneities were studied owing to numerical simulations [68]. Such problems were also considered in the frame of a statistical and analytical model [63] or by using the quasilinear theory with wave diffusion coefficients, involving resonance broadening phenomena [140].…”

Section: Particle Diffusion Processesmentioning

confidence: 99%

Turbulence and Microprocesses in Inhomogeneous Solar Wind Plasmas

Krafft

Volokitin

Gauthier

2019

Fluids

View full text Add to dashboard Cite

The random density fluctuations observed in the solar wind plasma crucially influence on the Langmuir wave turbulence generated by energetic electron beams ejected during solar bursts. Those are powerful phenomena consisting of a chain of successive processes leading ultimately to strong electromagnetic emissions. The small-scale processes governing the interactions between the waves, the beams and the inhomogeneous plasmas need to be studied to explain such macroscopic phenomena. Moreover, the complexity induced by the plasma irregularities requires to find new approaches and modelling. Therefore theoretical and numerical tools were built to describe the Langmuir wave turbulence and the beam’s dynamics in inhomogeneous plasmas, in the form of a self-consistent Hamiltonian model including a fluid description for the plasma and a kinetic approach for the beam. On this basis, numerical simulations were performed in order to shed light on the impact of the density fluctuations on the beam dynamics, the electromagnetic wave radiation, the generation of Langmuir wave turbulence, the waves’ coupling and decay phenomena involving Langmuir and low frequency waves, the acceleration of beam electrons, their diffusion mechanisms, the modulation of the Langmuir waveforms and the statistical properties of the radiated fields’ distributions. The paper presents the main results obtained in the form of a review.

show abstract

Section: Particle Diffusion Processesmentioning

confidence: 99%

Turbulence and Microprocesses in Inhomogeneous Solar Wind Plasmas

Krafft

Volokitin

Gauthier

2019

Fluids

View full text Add to dashboard Cite

show abstract

“…Drummond & Pines 1962;Vedenov et al 1962). This utilises the WKB approximation where we are treating waves as quasi-particles interacting resonantly ω pe (r) = kv, where ω pe (r) is the background plasma angular frequency (Bian et al 2014). Using f (v, r, t) as the electron distribution function and W(v, r, t) as the Langmuir wave spectral energy density in the one dimension of propagation, we can describe the time evolution using…”

Section: Modelmentioning

confidence: 99%

Stopping frequency of type III solar radio bursts in expanding magnetic flux tubes

Reid

Kontar

2015

A&A

Self Cite

View full text Add to dashboard Cite

Aims. Understanding the properties of type III radio bursts in the solar corona and interplanetary space is one of the best ways to remotely deduce the characteristics of solar accelerated electron beams and the solar wind plasma. One feature of all type III bursts is the lowest frequency they reach (or stopping frequency). This feature reflects the distance from the Sun that an electron beam can drive the observable plasma emission mechanism. The stopping frequency has never been systematically studied before from a theoretical perspective. Methods. Using numerical kinetic simulations, we explore the different parameters that dictate how far an electron beam can travel before it stops inducing a significant level of Langmuir waves, responsible for plasma radio emission. We use the quasilinear approach to model the resonant interaction between electrons and Langmuir waves self-consistently in inhomogeneous plasma, and take into consideration the expansion of the guiding magnetic flux tube and the turbulent density of the interplanetary medium. Results. We find that the rate of radial expansion has a significant effect on the distance an electron beam travels before enhanced levels of Langmuir waves, hence radio waves, cease. Radial expansion of the guiding magnetic flux tube rarefies the electron stream to the extent that the density of non-thermal electrons is too low to drive Langmuir wave production. The initial conditions of the electron beam have a significant effect, where decreasing the beam density or increasing the spectral index of injected electrons would cause higher type III stopping frequencies. We also demonstrate how the intensity of large-scale density fluctuations increases the highest frequency to which Langmuir waves can be driven by the beam and how the magnetic field geometry can be the cause of type III bursts that are only observed at high coronal frequencies.

show abstract

“…The two main effects we found of increasing density fluctuations on the electric field distribution are a reduction in the mean of log E and a broadening of the local distribution in log E, with both effects occurring at a similar rate. We explain these effects via the process of resonance broadening due to density fluctuations following Bian et al (2014), see also ; . For homogeneous plasma the wave-particle interaction has a sharp resonance function δ(ω − kv) so electrons only interact with waves that have a phase velocity equal to their velocity.…”

Section: Resonance Broadening Of the Beam-plasma Instabilitymentioning

confidence: 99%

“…For inhomogeneous plasma the waves generated by the electrons are refracted over a range ∆v. Then the plasma waves averaged over density perturbation scales can be viewed resonate with electrons over a broader region in velocity space with an extent ∆v = ∆ω/k centred at v = ω/k (Bian et al 2014).…”

Section: Resonance Broadening Of the Beam-plasma Instabilitymentioning

confidence: 99%

Langmuir wave electric fields induced by electron beams in the heliosphere

Reid

Kontar

2017

A&A

Self Cite

View full text Add to dashboard Cite

Solar electron beams responsible for type III radio emission generate Langmuir waves as they propagate out from the Sun. The Langmuir waves are observed via in-situ electric field measurements. These Langmuir waves are not smoothly distributed but occur in discrete clumps, commonly attributed to the turbulent nature of the solar wind electron density. Exactly how the density turbulence modulates the Langmuir wave electric fields is understood only qualitatively. Using weak turbulence simulations, we investigate how solar wind density turbulence changes the probability distribution functions, mean value and variance of the beam-driven electric field distributions. Simulations show rather complicated forms of the distribution that are dependent upon how the electric fields are sampled. Generally the higher magnitude of density fluctuations reduce the mean and increase the variance of the distribution in a consistent manor to the predictions from resonance broadening by density fluctuations. We also demonstrate how the properties of the electric field distribution should vary radially from the Sun to the Earth and provide a numerical prediction for the in-situ measurements of the upcoming Solar Orbiter and Solar Probe Plus spacecraft.

show abstract

Resonance broadening due to particle scattering and mode coupling in the quasi‐linear relaxation of electron beams

Cited by 16 publications

References 64 publications

Turbulence and Microprocesses in Inhomogeneous Solar Wind Plasmas

Turbulence and Microprocesses in Inhomogeneous Solar Wind Plasmas

Stopping frequency of type III solar radio bursts in expanding magnetic flux tubes

Langmuir wave electric fields induced by electron beams in the heliosphere

Contact Info

Product

Resources

About