Non-resonant acceleration of charged particles driven by the associated effects of the radiation reaction

2020 ◽  
Vol 86 (5) ◽  
Author(s):  
F. Russman ◽  
I. Almansa ◽  
E. Peter ◽  
S. Marini ◽  
F. B. Rizzato
Keyword(s):  
High Frequency ◽  
Charged Particles ◽  
Localization Length ◽  
Hamiltonian Formalism ◽  
Radiation Reaction ◽  
Speed Of Light ◽  
Wave Localization ◽  
Particle Speed ◽  
Resonant Acceleration ◽  
Localization Region

In the present analysis, we study effects of the radiation reaction (RR) on the dynamics of charged particles submitted to the action of localized longitudinal high-frequency carriers travelling at the speed of light. As the wave's crests and troughs keep overtaking particles, dissipative RR forces tend to drag particles alongside the wave in an effort to reduce the relative wave–particle speed. Particles of course never reach the phase velocity of the wave, but are instead driven to an ever-growing velocity, towards the speed of light, while in the wave localization region. We developed a modified average Hamiltonian formalism capable of describing the intricacies of the corresponding dynamics. The modified formalism agrees with simulations and is of particular usefulness in the study of optimum values for the localization length and maximum wave amplitude.

scholarly journals Radiation Reaction of Charged Particles Orbiting a Magnetized Schwarzschild Black Hole

2018 ◽  
Vol 861 (1) ◽  
pp. 2 ◽  
Author(s):  
Arman Tursunov ◽  
Martin Kološ ◽  
Zdeněk Stuchlík ◽  
Dmitri V. Gal’tsov
Keyword(s):  
Black Hole ◽  
Charged Particles ◽  
Radiation Reaction ◽  
Schwarzschild Black Hole

scholarly journals Guiding-centre transformation of the radiation–reaction force in a non-uniform magnetic field

2015 ◽  
Vol 81 (5) ◽  
Author(s):  
E. Hirvijoki ◽  
J. Decker ◽  
A. J. Brizard ◽  
O. Embréus
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Uniform Magnetic Field ◽  
Reaction Force ◽  
Charged Particles ◽  
Collision Operator ◽  
Radiation Reaction ◽  
Transform Method ◽  
Lie Transform ◽  
Radiation Reaction Force

In this paper, we present the guiding-centre transformation of the radiation–reaction force of a classical point charge travelling in a non-uniform magnetic field. The transformation is valid as long as the gyroradius of the charged particles is much smaller than the magnetic field non-uniformity length scale, so that the guiding-centre Lie-transform method is applicable. Elimination of the gyromotion time scale from the radiation–reaction force is obtained with the Poisson-bracket formalism originally introduced by Brizard (Phys. Plasmas, vol. 11, 2004, 4429–4438), where it was used to eliminate the fast gyromotion from the Fokker–Planck collision operator. The formalism presented here is applicable to the motion of charged particles in planetary magnetic fields as well as in magnetic confinement fusion plasmas, where the corresponding so-called synchrotron radiation can be detected. Applications of the guiding-centre radiation–reaction force include tracing of charged particle orbits in complex magnetic fields as well as the kinetic description of plasma when the loss of energy and momentum due to radiation plays an important role, e.g. for runaway-electron dynamics in tokamaks.

scholarly journals High-frequency dynamics of wave localization

1999 ◽  
Vol 60 (6) ◽  
pp. R6313-R6315 ◽  
Author(s):  
C. W. J. Beenakker ◽  
K. J. H. van Bemmel ◽  
P. W. Brouwer
Keyword(s):  
High Frequency ◽  
Wave Localization

scholarly journals Ultraintense Laser-Driven Nonthermal Acceleration of Charged Particles in the Near-QED Regime

2021 ◽  
Author(s):  
Yulong Hu ◽  
Baifei Shen ◽  
Jiancai Xu ◽  
Yasuhiro Kuramitsu ◽  
Hideaki Takabe ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
Power Law ◽  
Laser Intensity ◽  
Critical Role ◽  
Charged Particles ◽  
Radiation Reaction ◽  
Intense Laser ◽  
Acceleration Process ◽  
Qed Regime ◽  
Power Law Index

Abstract Here, we have studied the nonthermal acceleration of energetic electrons/protons under the near-QED regime by extending the laser intensity beyond 1023 W/cm2 based on a two-dimensional particle-in-cell simulation. The radiation-reaction (RR) effect plays a critical role and brings a quantum stochastic effect to the charged-particle acceleration process. Background electrons in plasma are accelerated in an intense laser field to several GeVs with strong oscillations and thus radiate γ-ray photons. The emitting γ-photons have a broad energy spectrum with maximal energy up to 3 GeV and result in radiation-reaction trapping of the electrons, forming a relativistic plasma bunch in the plasma channel. The accumulation of electrons and protons produces a charge-separation field for the acceleration/deceleration of charged particles. The accelerated electrons have a nonthermal spectrum with a power-law index of 1.5 with a laser intensity 1023 W/cm2 lower than that in the non-QED regime. As the laser intensity further increases over 1024 W/cm2, the power-law index further drops to 1.2. Moreover, the energy spectrum of accelerated protons has a nonthermal distribution with a power-law index of 0.7, which is much lower than that of electrons in the near-QED regime.

scholarly journals Evidence for particle acceleration in the magnetospheric cusp

2008 ◽  
Vol 26 (7) ◽  
pp. 1993-1997 ◽  
Author(s):  
J. Chen
Keyword(s):  
Electric Fields ◽  
Charged Particles ◽  
Magnetic Fluctuations ◽  
Adjacent Region ◽  
Left Hand ◽  
Power Spectral ◽  
Large Fluctuations ◽  
Magnetospheric Cusp ◽  
New Evidence ◽  
Resonant Acceleration

Abstract. New evidence reveals that the charged particles can be energized locally in the magnetospheric cusp. The power spectral density of the cusp magnetic fluctuations shows increases by up to four orders of magnitude in comparison to an adjacent region. Large fluctuations of the cusp electric fields have been observed with an amplitude of up to 350 mV/m. The measured left-hand polarization of the cusp electric field at ion gyro-frequencies indicates that the cyclotron resonant acceleration mechanism is working in this region. The cyclotron resonant acceleration can energize ions from keV to MeV in seconds.

Hamiltonian theory of the generalized oscillation-centre transformation

1988 ◽  
Vol 39 (1) ◽  
pp. 81-102 ◽  
Author(s):  
B. Weyssow ◽  
R. Balescu
Keyword(s):  
High Frequency ◽  
Ponderomotive Force ◽  
Hamiltonian Formalism ◽  
Larmor Frequency ◽  
Static Field ◽  
Canonical Variables ◽  
Hamiltonian Theory ◽  
External Frequency ◽  
High Frequency Electromagnetic Field ◽  
Physical Quantities

The theory of the slow reaction of a charged particle in the combined presence of a strong quasi-static magnetic field and a high-frequency electromagnetic field (generalized oscillation-centre motion) is constructed by using a Hamiltonian formalism with non-canonical variables and pseudo-canonical transformations. The theory combines the features studied in our previous works for the case in which only one of the previously mentioned fields is present. The new averaging transformation is based on the fact that the Larmor frequency of the quasi-static field is of the same order as the external frequency of the high-frequency field. Our theory is manifestly gauge-invariant and involves only physical quantities (particle velocity and electromagnetic fields). Explicit expressions for the drift velocity of the oscillation centre and for the ponderomotive force are derived.

scholarly journals Anomalous Anderson localization behaviors in disordered pseudospin systems

2017 ◽  
Vol 114 (16) ◽  
pp. 4087-4092 ◽  
Author(s):  
A. Fang ◽  
Z. Q. Zhang ◽  
Steven G. Louie ◽  
C. T. Chan
Keyword(s):  
Disordered Systems ◽  
Anderson Localization ◽  
Random Potential ◽  
Incident Angle ◽  
Localization Length ◽  
Normal Incidence ◽  
Wave Localization ◽  
Sharp Transition ◽  
Angle Dependence ◽  
Localization Behavior

We discovered unique Anderson localization behaviors of pseudospin systems in a 1D disordered potential. For a pseudospin-1 system, due to the absence of backscattering under normal incidence and the presence of a conical band structure, the wave localization behaviors are entirely different from those of conventional disordered systems. We show that there exists a critical strength of random potential (Wc), which is equal to the incident energy (E), below which the localization length ξ decreases with the random strength W for a fixed incident angle θ. But the localization length drops abruptly to a minimum at W=Wc and rises immediately afterward. The incident angle dependence of the localization length has different asymptotic behaviors in the two regions of random strength, with ξ∝sin−4θ when W<Wc and ξ∝sin−2θ when W>Wc. The existence of a sharp transition at W=Wc is due to the emergence of evanescent waves in the systems when W>Wc. Such localization behavior is unique to pseudospin-1 systems. For pseudospin-1/2 systems, there is also a minimum localization length as randomness increases, but the transition from decreasing to increasing localization length at the minimum is smooth rather than abrupt. In both decreasing and increasing regions, the θ dependence of the localization length has the same asymptotic behavior ξ∝sin−2θ.

Resonant acceleration of charged particles in the presence of random fluctuations

2011 ◽  
Vol 84 (4) ◽  
Author(s):  
Anton Artemyev ◽  
Dmitri Vainchtein ◽  
Anatoly Neishtadt ◽  
Lev Zelenyi
Keyword(s):  
Charged Particles ◽  
Random Fluctuations ◽  
Resonant Acceleration
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