Expansion of Solar Coronal Hot Electrons in an Inhomogeneous Magnetic Field: 1D PIC Simulation

Sun, Jicheng; Gao, Xinliang; Ke, Yangguang; Lu, Quanming; Wang, Xueyi; Wang, Shui

doi:10.3847/1538-4357/ab5060

Cited by 6 publications

(5 citation statements)

References 39 publications

(50 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The PIC simulation provides a powerful tool to study the waves in the space plasma (e.g., Chen et al, 2016; Sun et al, 2019). In this paper, 2‐D electromagnetic PIC simulations are employed to investigate the wave normal angle distribution of magnetosonic waves driven by a proton ring distribution.…”

Section: Simulation Modelmentioning

confidence: 99%

Wave Normal Angle Distribution of Magnetosonic Waves in the Earth's Magnetosphere: 2‐D PIC Simulation

2020

Self Cite

View full text Add to dashboard Cite

Radiation belt electrons can be accelerated and scattered by magnetosonic waves in the Earth's magnetosphere, and the scattering rate of electrons is sensitive to the wave normal angle. However, observationally it is difficult to identify the wave normal angle within a few degrees. In this study, using 2-D particle-in-cell (PIC) simulations, we investigate the wave normal angle distribution of magnetosonic waves excited by ring distribution protons. Both the linear theory and simulations have shown that the wave normal angles are distributed over a narrow range (82°-89°) with a major peak at about 85°during the linear growth stage when the proton ring velocity is close to the Alfven speed. In addition, 2-D PIC simulations further demonstrated that the waves tend to have larger wave normal angles (84°-89°) during the saturation stage since the waves with smaller wave normal angles are dissipated faster. It is also found that wave normal angles decrease with the increase of wave frequency. With the increase of the ring velocity of the proton ring distribution, the perpendicular wavenumber of excited magnetosonic waves decreases, which leads to the decrease of the wave normal angle. The simulation results provide a valuable insight to understand the property of magnetosonic waves, and the findings are useful for the global simulations of radiation belt dynamics. Key Points: • Using 2-D PIC simulations, the wave normal angle distribution of magnetosonic waves has been investigated • The wave normal angles are distributed over a narrow range (82°-89°) during the linear growth stage • The wave normal angles decrease with the increase of the ring velocity of the proton ring distribution SUN ET AL.Figure 6. (a) The power spectral density of δB ‖ /B 0 and (b) the wave normal angle as a function of frequency and time for the simulation in the dipole magnetic field. (c) The average wave normal angle <θ> versus the wave frequency ω.

show abstract

Section: Simulation Modelmentioning

confidence: 99%

Wave Normal Angle Distribution of Magnetosonic Waves in the Earth's Magnetosphere: 2‐D PIC Simulation

2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…The PIC simulation provides a powerful tool to study the interaction between waves and particles in the space plasma (Chen et al, 2016;Sun et al, 2019Sun et al, , 2020. In this paper, 1-D electromagnetic PIC simulations are used to investigate the excitation of rising-tone magnetosonic waves, which retain 3-D electromagnetic fields and particle velocities but only 1-D spatial variation in the x direction.…”

Section: Simulation Modelmentioning

confidence: 99%

Particle‐in‐Cell Simulation of Rising‐Tone Magnetosonic Waves

Sun

Chen

Wang

et al. 2020

Geophysical Research Letters

Self Cite

View full text Add to dashboard Cite

Recent observations have reported that magnetosonic waves can exhibit rising-tone structures in the frequency-time spectrogram. However, the generation mechanism has not been identified yet. In this paper, we investigate the generation of rising-tone magnetosonic waves in the terrestrial magnetosphere using 1-D particle-in-cell (PIC) simulations, in which the plasma consists of three components: cool electrons, cool protons and ring distribution protons. We find that the magnetosonic waves excited by the ring distribution protons can form a rising-tone structure with frequency of the structure ranging from about 0.5Ω lh to nearly Ω lh , where Ω lh is the lower hybrid frequency. It is further demonstrated that the rising frequency of magnetosonic waves can be accounted for by the scattering of ring distribution protons. Moreover, the rising-tone timescale obtained by PIC simulation is compared with the satellite observation. Our findings provide some new insights to understand the nonlinear evolution of plasma waves in the Earth's magnetosphere. Plain Language Summary Magnetosonic waves in the Earth's inner magnetosphere often exhibit a series of harmonics of the local proton gyrofrequency. Recent observations found that they also have some other features, such as rising-tone spectra and quasiperiodicity in time. Since these phenomena are similar to the rising-tone chorus and electromagnetic ion cyclotron waves, many researchers speculated the generation of rising-tone magnetosonic waves may be also related to the nonlinear waveparticle interaction. In spite of the speculation, the specific generation mechanism of rising-tone magnetosonic waves has not been identified yet. In this paper, we perform 1-D particle-in-cell (PIC) simulations to investigate the generation of rising-tone magnetosonic waves. It is found that the magnetosonic waves excited by the ring distribution protons can form a rising-tone structure. In addition, we also demonstrate that the rising-tone magnetosonic waves can be accounted for by the scattering of ring distribution protons.

show abstract

“…The WHAMP (Waves in Homogeneous Anisotropic Magnetized Plasma) model (Ronnmark, 1982), which can be easily accessed on the website (https://github.com/irfu/whamp), is utilized to calculate the dispersion relation of whistler mode waves and associated linear growth rates. This code has been widely used in previous works (H. Y. Chen et al, 2018; Denton, 2018; Fan et al, 2019; Sun et al, 2019; Xiao et al, 2007).…”

Section: Linear Theoretical Modelmentioning

confidence: 99%

Whistler Mode Waves Excited by Anisotropic Hot Electrons With a Drift Velocity in Earth's Magnetosphere: Linear Theory

2020

Self Cite

View full text Add to dashboard Cite

With a linear theoretical model, we have investigated the properties of whistler waves excited by anisotropic hot electrons with a drift velocity parallel to the background magnetic field, which is usually neglected in previous studies. It is found that a finite drift velocity can significantly change the properties of excited whistler waves, resulting in distinct properties for parallel and antiparallel propagating waves. In the high‐beta regime, as the drift velocity increases, the frequency of parallel propagating whistler waves increases, while that of antiparallel propagating waves is found to decline. So parallel and antiparallel propagating whistler waves appear in different frequency bands. However, the growth rate of parallel wave is always smaller than that of antiparallel wave and falls below 10−2Ωe for large drift velocities (vd/vth > 1.5), in which case the parallel wave may be too weak to be observed. Generally, the growth rate of whistler waves in both directions is enhanced with the increasing anisotropy or proportion of hot electrons. In the low‐beta regime, the trends of the frequency and linear growth rate of excited whistler waves are quite similar to those in the high‐beta regime. But with the increase of the drift velocity, the wave normal angle of parallel propagating whistler waves gradually declines until reaching 0, while that of antiparallel propagating waves continues to increase. Our study may be helpful to understand various whistler mode spectra observed in the Earth's magnetosphere.

show abstract

Expansion of Solar Coronal Hot Electrons in an Inhomogeneous Magnetic Field: 1D PIC Simulation

Cited by 6 publications

References 39 publications

Wave Normal Angle Distribution of Magnetosonic Waves in the Earth's Magnetosphere: 2‐D PIC Simulation

Wave Normal Angle Distribution of Magnetosonic Waves in the Earth's Magnetosphere: 2‐D PIC Simulation

Particle‐in‐Cell Simulation of Rising‐Tone Magnetosonic Waves

Whistler Mode Waves Excited by Anisotropic Hot Electrons With a Drift Velocity in Earth's Magnetosphere: Linear Theory

Contact Info

Product

Resources

About