On the generation of ion beamlets in the magnetotail: Resonant acceleration versus stochastic acceleration

2013 ◽  
Vol 118 (9) ◽  
pp. 5445-5453 ◽  
Author(s):  
M. S. Dolgonosov ◽  
G. Zimbardo ◽  
S. Perri ◽  
A. Greco
Keyword(s):  
Stochastic Acceleration ◽  
Resonant Acceleration

scholarly journals Cyclotron resonance effects on stochastic acceleration of light ionospheric ions

1982 ◽  
Vol 9 (9) ◽  
pp. 1053-1056 ◽  
Author(s):  
Nagendra Singh ◽  
R. W. Schunk ◽  
J. J. Sojka
Keyword(s):  
Cyclotron Resonance ◽  
Stochastic Acceleration ◽  
Resonance Effects

scholarly journals Electron energy spectrum produced by stochastic acceleration in the laser–plasma interaction

2017 ◽  
Vol 35 (2) ◽  
pp. 265-273 ◽  
Author(s):  
E. Khalilzadeh ◽  
A. Chakhmachi ◽  
J. Yazdanpanah
Keyword(s):  
Energy Spectrum ◽  
Laser Pulse ◽  
Rise Time ◽  
Wave Breaking ◽  
Boundary Effect ◽  
Maximum Energy ◽  
Intense Laser ◽  
Stochastic Acceleration ◽  
Direct Laser ◽  
Short Rise Time

AbstractIn this paper, the electrons energy spectrum produced by stochastic acceleration in the interaction of an intense laser pulse with the underdense plasma is described by employing the fully kinetic 1D-3 V particle-in-cell simulation. In this way, two finite laser pulses with the same length 200 fs and with two different rise times 30 and 60 fs are typically selected. It is shown that the maximum energy of electrons in the laser pulse with the short rise time (30 fs) is about eight times greater than the maximum energy of the electrons with the long rise time (60 fs). Furthermore, unlike the pulse with the short rise time, the shape of energy spectrum and the electrons temperature in the long rise time laser pulse are approximately unchanged over the time. These results originated from the fact that in the case of long rise time laser pulse, all electrons are accelerated by the one chaotic mechanism because of the scattered fields generated in the plasma, but in the case of short rise time laser pulse, three different mechanisms accelerate the electrons: first, the stochastic acceleration because of the nonlinear wave breaking via plasma-vacuum boundary effect; second, the stochastic acceleration initiated by the wave breaking; and third, the direct laser acceleration of the released electrons.

Formation of SCR energy spectra during stochastic acceleration with allowance for Coulomb losses

2000 ◽  
Vol 26 (2) ◽  
pp. 122-128 ◽  
Author(s):  
V. M. Ostryakov ◽  
Yu. Yu. Kartavykh ◽  
G. A. Koval'tsov
Keyword(s):  
Energy Spectra ◽  
Stochastic Acceleration

scholarly journals Stochastic Acceleration of ∼0.1–5 keV Pickup Ions in the Heliotail

2018 ◽  
Vol 860 (2) ◽  
pp. 170 ◽  
Author(s):  
E. J. Zirnstein ◽  
R. Kumar ◽  
J. Heerikhuisen ◽  
D. J. McComas ◽  
A. Galli
Keyword(s):  
Pickup Ions ◽  
Stochastic Acceleration

scholarly journals A Testable Stochastic Acceleration Model for Flares in Sagittarius A*

2006 ◽  
Vol 648 (2) ◽  
pp. 1020-1025 ◽  
Author(s):  
Siming Liu ◽  
Vahe Petrosian ◽  
Fulvio Melia ◽  
Christopher L. Fryer
Keyword(s):  
Stochastic Acceleration ◽  
Sagittarius A ◽  
Acceleration Model

scholarly journals Fermi bubbles from stochastic acceleration of electrons in a Galactic outflow

2019 ◽  
Vol 622 ◽  
pp. A203 ◽  
Author(s):  
P. Mertsch ◽  
V. Petrosian
Keyword(s):  
Large Scale ◽  
Transport Coefficients ◽  
Strong Shock ◽  
High Energy ◽  
Brightness Distribution ◽  
Shock Acceleration ◽  
Galactic Centre ◽  
Large Reservoir ◽  
Stochastic Acceleration ◽  
Multi Wavelength

The discovery of the Fermi bubbles – a huge bilobular structure seen in GeV gamma-rays above and below the Galactic centre – implies the presence of a large reservoir of high energy particles at ~10 kpc from the disk. The absence of evidence for a strong shock coinciding with the edge of the bubbles, and constraints from multi-wavelength observations point towards stochastic acceleration by turbulence as a likely mechanism of acceleration. We have investigated the time-dependent acceleration of electrons in a large-scale outflow from the Galactic centre. For the first time, we present a detailed numerical solution of the particle kinetic equation that includes the acceleration, transport and relevant energy loss processes. We also take into account the addition of shock acceleration of electrons at the bubble’s blast wave. Fitting to the observed spectrum and surface brightness distribution of the bubbles allows determining the transport coefficients, thereby shedding light on the origin of the Fermi bubbles.

scholarly journals Acceleration of protons and heavy ions to suprathermal energies during dipolarizations in the near-Earth magnetotail

2019 ◽  
Vol 37 (4) ◽  
pp. 549-559 ◽  
Author(s):  
Andrei Y. Malykhin ◽  
Elena E. Grigorenko ◽  
Elena A. Kronberg ◽  
Patrick W. Daly ◽  
Ludmila V. Kozak
Keyword(s):  
Heavy Ions ◽  
Finite Energy ◽  
Flux Growth ◽  
Oxygen Ions ◽  
Strong Energy ◽  
Light Ions ◽  
Energy Gains ◽  
Fast Flow ◽  
Suprathermal Ions ◽  
Resonant Acceleration

Abstract. In this work we present an analysis of the dynamics of suprathermal ions of different masses (H+, He+, O+) during prolonged dipolarizations in the near-Earth magnetotail (X>-17RE) according to Cluster/RAPID observations in 2001–2005. All dipolarizations from our database were associated with fast flow braking and consisted of multiple dipolarization fronts (DFs). We found statistically that fluxes of suprathermal ions started to increase ∼1 min before the dipolarization onset and continued to grow for ∼1 min after the onset. The start of flux growth coincided with the beginning of a decrease in the spectral index γ. The decrease in γ was observed for protons for ∼1 min after the dipolarization onset, and for He+ and O+ ions for ∼3 and ∼5 min after the onset respectively. The negative variations of γ for O+ ions were ∼2.5 times larger than for light ions. This demonstrates more efficient acceleration for heavy ions. The strong negative variations of γ were observed in finite energy ranges for all ion components. This indicates the possibility of nonadiabatic resonant acceleration of ions in the course of their interaction with multiple DFs during dipolarizations. Our analysis showed that some fraction of light ions can be accelerated up to energies ≥600 keV and some fraction of oxygen ions can be accelerated up to ∼1.2 MeV. Such strong energy gains cannot be explained by acceleration at a single propagating DF and suggest the possibility of multistage ion acceleration in the course of their interaction with multiple DFs during the prolonged dipolarizations.

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