On the nature of particle energization via resonant wave-particle interaction in the inhomogeneous magnetospheric plasma

Shklyar, D. R.

doi:10.5194/angeo-29-1179-2011

Cited by 47 publications

(54 citation statements)

References 22 publications

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“…A similar question about energy sources has been previously raised for large‐amplitude whistler waves observed in the outer radiation belt [ Cattell et al , ; Cully et al , ; Kellogg et al , ; Wilson et al , ] and capable of providing fast energization of electrons trapped into the Landau or cyclotron resonances [ Trakhtengerts et al , ; Agapitov et al , , ; Osmane et al , ]. Shklyar [] has shown that whistler wave energy is insufficient to provide transport of resonant trapped electrons to 30°–40° latitude, where whistlers are still observed [ Cattell et al , ; Kellogg et al , ; Agapitov et al , ]. Shklyar [] has shown that the energization of resonant trapped electrons can be balanced by energy losses of untrapped electrons scattered by whistler waves [see also Shklyar and Matsumoto , ].…”

Section: Introductionmentioning

confidence: 80%

“…The energy loss rate is largely provided by Landau resonant untrapped electrons. The energy loss rate of untrapped electrons per unit area is given by expression very similar to equation [ Shklyar , ; Vasko et al , ]

\frac{normald W_{normalut}}{normald t} = - \frac{normald B}{normald t} Ω_{normalsep} \int μ F_{normalut} (\infty, v_{ϕ}, μ) normald μ

where

F_{normalut} (\infty, v_{ϕ}, μ)

is the distribution function of Landau resonant untrapped electrons at

| z | \to \infty

. In fact, electrons effectively exchanging energy with EH are those within the resonance width,

| v_{∥} - v_{ϕ} | ≲ {(2 e Φ_{0} / m_{e})}^{1 / 2}

.…”

Section: Energization Of Trapped Electronsmentioning

confidence: 99%

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Electron holes in the outer radiation belt: Characteristics and their role in electron energization

et al. 2017

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Van Allen Probes have detected electron holes (EHs) around injection fronts in the outer radiation belt. Presumably generated near equator, EHs propagate to higher latitudes potentially resulting in energization of electrons trapped within EHs. This process has been recently shown to provide electrons with energies up to several tens of keV and requires EH propagation up to rather high latitudes. We have analyzed more than 100 EHs observed around a particular injection to determine their kinetic structure and potential energy sources supporting the energization of trapped electrons. EHs propagate with velocities from 1000 to 20,000 km/s (a few times larger than the thermal velocity of the coldest background electron population). The parallel scale of observed EHs is from 0.3 to 3 km that is of the order of hundred Debye lengths. The perpendicular to parallel scale ratio is larger than one in a qualitative agreement with the theoretical scaling relation. The amplitudes of EH electrostatic potentials are generally below 100 V. We determine the properties of the electron population trapped within EHs by making use of the Bernstein‐Green‐Kruskal analysis and via analysis of EH magnetic field signatures. The density of the trapped electron population is on average 20% of the background electron density. The perpendicular temperature of the trapped population is on average 300 eV and is larger for faster EHs. We show that energy losses of untrapped electrons scattered by EHs in the inhomogeneous background magnetic field may balance the energization of trapped electrons.

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Section: Introductionmentioning

confidence: 80%

\frac{normald W_{normalut}}{normald t} = - \frac{normald B}{normald t} Ω_{normalsep} \int μ F_{normalut} (\infty, v_{ϕ}, μ) normald μ

where

F_{normalut} (\infty, v_{ϕ}, μ)

is the distribution function of Landau resonant untrapped electrons at

| z | \to \infty

. In fact, electrons effectively exchanging energy with EH are those within the resonance width,

| v_{∥} - v_{ϕ} | ≲ {(2 e Φ_{0} / m_{e})}^{1 / 2}

.…”

Section: Energization Of Trapped Electronsmentioning

confidence: 99%

Electron holes in the outer radiation belt: Characteristics and their role in electron energization

et al. 2017

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“…Thus, integral operators were proposed to include them into a kinetic equation [40][41][42] to take this process into account. However, in many plasma systems with nonlinear wave-particle interaction, trapping effects are somehow compensated by effects of nonlinear scattering [35,43,44], i.e. the rapid acceleration of a small population of trapped particles corresponds to a slight energy decrease for a large population of scattered particles.…”

Section: Introductionmentioning

confidence: 99%

Probabilistic approach to nonlinear wave-particle resonant interaction

et al. 2017

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Citation: ARTEMYEV, A.V. ...et al., 2017. Probabilistic approach to nonlinear wave-particle resonant interaction. Physical Review E, 95:023204.Additional Information:• This paper was accepted for publication in the journal Physi- Probabilistic approach to nonlinear wave-particle resonant interaction In this paper we provide a theoretical model describing the evolution of the charged particle distribution function in a system with nonlinear wave particle interactions. Considering a system with strong electrostatic waves propagating in an inhomogeneous magnetic field, we demonstrate that individual particle motion can be characterized by the probability of trapping into the resonance with the wave and by the efficiency of scattering at resonance. These characteristics, being derived for a particular plasma system, can be used to construct a kinetic equation (or generalized FokkerPlanck equation) modelling the long-term evolution of the particle distribution. In this equation, effects of charged particle trapping and transport in phase space are simulated with a nonlocal operator. We demonstrate that solutions of the derived kinetic equations agree with results of test particle tracing. The applicability of the proposed approach for the description of space and laboratory plasma systems is also discussed.

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“…It was shown in a number of studies that ULF waves at the boundaries of the magnetosphere are able to enhance the radial diffusion [ Elkington et al , 1999; Hudson et al , 1999, 2000, 2001]. Models that are based on the interaction of the electron population with waves [ Shklyar , 2011; Shklyar and Matsumoto , 2009; Shprits et al , 2008; Omura et al , 2007; Horne et al , 2005; Summers and Thorne , 2003; Summers et al , 1998, 2002, 2004; Albert , 2003, 2005] assume the local diffusion in the pitch angle and in the energy space. This results in the acceleration of one part of electron population and the filling of the loss cone by the subsequent precipitation of another part.…”

Section: Introductionmentioning

confidence: 99%

Time scaling of the electron flux increase at GEO: The local energy diffusion model vs observations

et al. 2012

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[1] The characteristic time scaling of the electron flux evolution at geosynchronous orbit (GEO), resulting from the quasilinear wave-particle interaction, is investigated. The upper limit of the electron flux increase rate, due to the interaction with waves, is deduced from the energy diffusion equation (EDE). Such a time scaling allows for a comparison with experimentally measured fluxes of energetic electrons at GEO. It is shown that the analytically deduced time scaling is too slow to explain the observed increase in fluxes. It is concluded that radial diffusion plays the most significant role in the build up of the energetic electrons population at GEO. However, this conclusion is only justified if the seed population energies are very low.

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On the nature of particle energization via resonant wave-particle interaction in the inhomogeneous magnetospheric plasma

Cited by 47 publications

References 22 publications

Electron holes in the outer radiation belt: Characteristics and their role in electron energization

Electron holes in the outer radiation belt: Characteristics and their role in electron energization

Probabilistic approach to nonlinear wave-particle resonant interaction

Time scaling of the electron flux increase at GEO: The local energy diffusion model vs observations

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