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In this paper, electromagnetic emissions produced in a thin beam-plasma system are studied using two-dimensional particle-in-cell simulations. For the first time, the problem of emission generation in such a system is considered in the…

Plasma Physics · Physics 2016-05-25 V. V. Annenkov , I. V. Timofeev , E. P. Volchok

Plasma outflows from gamma-ray bursts (GRB), pulsar winds, relativistic jets, and ultra-intense laser targets radiate high energy photons. However, radiation damping is ignored in conventional PIC simulations. In this letter, we study the…

Astrophysics · Physics 2007-05-23 Koichi Noguchi , Edison Liang , Kazumi Nishimura

In most PIC/MCC simulations of radio frequency capacitively coupled plasmas (CCPs) several simplifications are made: (i) fast neutrals are not traced, (ii) heavy particle induced excitation and ionization are neglected, (iii) secondary…

Plasma Physics · Physics 2015-06-23 A. Derzsi , I. Korolov , E. Schuengel , Z. Donko , J. Schulze

The beaming pattern of radiation emitted by a relativistically moving source like jets in microquasars, AGN and GRBs, is a key issue for understanding of acceleration and radiation processes in these objects. In this paper we introduce a…

High Energy Astrophysical Phenomena · Physics 2018-05-30 S. R. Kelner , E. Lefa , F. M. Rieger , F. A. Aharonian

Radiation from many astrophysical sources, e.g. gamma-ray bursts and active galactic nuclei, is believed to arise from relativistically shocked collisionless plasmas. Such sources often exhibit highly transient spectra evolving rapidly,…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Jacob Trier Frederiksen , Troels Haugboelle , Mikhail V. Medvedev , Aake Nordlund

We present the results of kinetic modelling of quantum effects in laser-beam interaction. In the developed numerical model, electron-positron pair production by hard photons, hard photon emission and the electromagnetic fields generated by…

Plasma Physics · Physics 2015-05-27 Evgeny Nerush , Igor Kostyukov

Plasma current instabilities can destabilize the plasma discharge and cool the plasma rapidly. In such $\textit{disruptions}$ or in the start-up phase of the reactor, inductive electric fields are generated which accelerate electrons to…

Plasma Physics · Physics 2024-10-30 Benjamin Buchholz

One of the most important unresolved issues in gamma-ray burst physics is the origin of the prompt gamma-ray spectrum. Its general non-thermal character and the softness in the X-ray band remain unexplained. We tackle these issues by…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Atul Chhotray , Davide Lazzati

Synchrotron emission from runaway electrons may be used to diagnose plasma conditions during a tokamak disruption, but solving this inverse problem requires rapid simulation of the electron distribution function and associated synchrotron…

Plasma Physics · Physics 2014-03-31 Matt Landreman , Adam Stahl , Tünde Fülöp

(abridged) Models of many astrophysical gamma-ray sources assume they contain a homogeneous distribution of electrons that are injected as a power-law in energy and evolve by interacting with radiation fields, magnetic fields and particles…

Astrophysics · Physics 2009-11-13 K. Manolakou , D. Horns , J. G. Kirk

Thermodynamic properties of the electron-positron plasma (or gas) at high and very high temperatures are investigated. To achieve this goal we have derived a number of analytical formulas for the Fermi-Dirac distribution functions (or…

Plasma Physics · Physics 2023-01-16 Alexei M. Frolov

We formulate empirically the rapidity density distribution of produced particles in multiple particle production. The assumed mechanism is that the produced particles are emitted isotropically from several emitting centers, located on the…

High Energy Physics - Phenomenology · Physics 2010-09-21 A. Ohsawa , E. H. Shubuya , M. Tamada

The emission mechanism of the gamma-ray bursts (GRBs) is still a matter of debates. The standard synchrotron energy spectrum of cooling electrons F_E ~ E^{-1/2} is much too soft to account for the majority of the observed spectral slopes.…

Astrophysics · Physics 2009-11-10 Boris E. Stern , Juri Poutanen

Nature's most powerful high-energy sources are capable of accelerating particles to high energy and radiate it away on extremely short timescales, even shorter than the light crossing time of the system. It is yet unclear what physical…

Plasma Physics · Physics 2022-01-03 Luca Comisso , Lorenzo Sironi

We have developed a numerical model for the temporal evolution of particle and photon spectra resulting from nonthermal processes at the shock fronts formed in merging clusters of galaxies. Fermi acceleration is approximated by injecting…

Astrophysics · Physics 2007-05-23 R. C. Berrington , C. D. Dermer

Computer aided engineering of multi-time-scale plasma systems which exhibit a quasi-steady state solution are challenging due to the large number of time steps required to reach convergence. Machine learning techniques combined with…

Plasma Physics · Physics 2025-10-03 Andrew T. Powis , Domenica Corona Rivera , Alexander Khrabry , Igor D. Kaganovich

We present new parametrisations of energy spectra of secondary particles, $\pi$-mesons, gamma-rays, electrons and neutrinos, produced in inelastic proton-proton collisions. The simple analytical approximations based on imulations of…

Astrophysics · Physics 2014-10-13 S. R. Kelner , F. A. Aharonian , V. V. Bugayov

High-energy astrophysical systems frequently contain collisionless relativistic plasmas that are heated by turbulent cascades and cooled by emission of radiation. Understanding the nature of this radiative turbulence is a frontier of…

High Energy Astrophysical Phenomena · Physics 2020-02-05 Vladimir Zhdankin , Dmitri A. Uzdensky , Gregory R. Werner , Mitchell C. Begelman

Resonant scattering of energetic protons off magnetic irregularities is the main process in cosmic ray diffusion. The typical theoretical description uses Alfven waves in the low frequency limit. We demonstrate that the usage of…

Solar and Stellar Astrophysics · Physics 2014-05-09 Cedric Schreiner , Felix Spanier

The demands on performance of advanced linear accelerator based facilities strongly depend on the quality of the particle beams produced by such machines. Indeed, state-of-the-art applications in photon production and high-energy physics…