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Related papers: Non-Maxwellian Proton Velocity Distributions in No…

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Recent inertial confinement fusion experiments have shown primary fusion spectral moments which are incompatible with a Maxwellian velocity distribution description. These results show that an ion kinetic description of the reacting ions is…

Within a test-particle description of the acceleration process in parallel nonrelativistic shocks, we present an analytic treatment of the electron injection. We estimate the velocity distribution of the injected electrons as the product of…

Astrophysics · Physics 2007-05-23 O. Petruk , R. Bandiera

The classic optical nebular diagnostics [N II], [O II], [O III], [S II], [S III], and [Ar III] are employed to search for evidence of non-Maxwellian electron distributions, namely $\kappa$ distributions, in a sample of well-observed…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 C. Mendoza , M. A. Bautista

Space plasmas are generally characterized by non-Maxwellian distributions with suprathermal populations, as routinely revealed by in situ observations. Such departures from standard Maxwellian distributions can be understood as signatures…

Plasma Physics · Physics 2026-05-18 Kamel Ourabah

Shock fronts in young supernova remnants are the best candidates for being sites of cosmic ray acceleration up to a few PeV, though conclusive experimental evidence is still lacking. Hadron acceleration is expected to increase the shock…

High Energy Astrophysical Phenomena · Physics 2015-06-11 M. Miceli , F. Bocchino , A. Decourchelle , G. Maurin , J. Vink , S. Orlando , F. Reale , S. Broersen

While supernova remnants (SNRs) have long been considered prime candidates as sources of cosmic rays, it is only recently that X-ray observations have identified several shell-type SNRs dominated by nonthermal emission, thus revealing…

Astrophysics · Physics 2007-05-23 Patrick Slane

Pickup ions are created when interstellar neutral atoms resonantly exchange charge with the solar wind (SW) ions, especially in the supersonic part of the wind, where they carry most of the plasma pressure. Here we present numerical…

Solar and Stellar Astrophysics · Physics 2016-12-21 Nikolai V. Pogorelov , Matthew C. Bedford , Igor A. Kryukov , Gary P. Zank

We present a new formalism to describe the ratios and profiles of emission lines from hydrogen in Balmer-dominated shocks. We use this model to interpret the measured widths and ratios of broad and narrow H-alpha, H-beta and Ly-alpha…

Astrophysics · Physics 2008-11-26 Kevin Heng , Richard McCray

This work presents a model for generating nonthermal power-law tails of particles' energy probability density functions in turbulent collisionless plasmas, applicable to both non-relativistic and relativistic scenarios. We propose that…

Plasma Physics · Physics 2026-05-05 Stanislav Boldyrev , Daniel Humphrey , Vadim Roytershteyn

The linear theory of shock acceleration predicts the maximum particle energy to be limited only by the acceleration time and the size of the shock. We study the combined effect of acceleration nonlinearity (shock modification by accelerated…

Astrophysics · Physics 2007-05-23 M. A. Malkov , P. H. Diamond , T. W. Jones

Possible modification in the velocity distribution in the non-resonant reaction rates leads to an extended reaction rate probability integral. The closed form representation for these thermonuclear functions are used to obtain the stellar…

Solar and Stellar Astrophysics · Physics 2014-09-09 H. J. Haubold , D. Kumar

Estimating the cosmic-ray acceleration efficiency $ \epsilon $ in supernova remnants (SNRs) through observations is a challenging task in general. Based on the Rankine-Hugoniot shock conditions, we find an anticorrelation between $ \epsilon…

High Energy Astrophysical Phenomena · Physics 2018-12-21 Yiran Zhang , Siming Liu

In the parts of the solar corona and solar wind that experience the fewest Coulomb collisions, the component proton, electron, and heavy ion populations are not in thermal equilibrium with one another. Observed differences in temperatures,…

Solar and Stellar Astrophysics · Physics 2015-06-05 Steven R. Cranmer , Adriaan A. van Ballegooijen

The solar wind plasma is a fully ionized and turbulent gas ejected by the outer layers of the solar corona at very high speed, mainly composed by protons and electrons, with a small percentage of helium nuclei and a significantly lower…

The formation of collisionless shock fronts is an ubiquitous phenomenon in space plasma environments. In the solar wind shocks might accompany coronal mass ejections, while even more violent events, such as supernovae, produce shock fronts…

High Energy Astrophysical Phenomena · Physics 2020-03-17 Cedric Schreiner , Patrick Kilian , Felix Spanier , Patricio A. Muñoz , Jörg Büchner

In the leptonic scenario for TeV emission from a few well-observed shell-type TeV supernova remnants (STTSNRs), very weak magnetic fields are inferred. If fast-mode waves are produced efficiently in the shock downstream, we show that they…

High Energy Astrophysical Phenomena · Physics 2010-06-02 Zhonghui Fan , Siming Liu , Christopher L. Fryer

The non-thermal X-rays from the SN 1006 NE rim present characteristic scale lengths that are interpreted in the context of diffusion of a relativistic electron. The adopted theoretical framework is the mathematical diffusion in 3D, 1D and…

Astrophysics · Physics 2011-09-28 Lorenzo Zaninetti

Astrophysical shocks at all scales, from those in the heliosphere up to the cosmological shock waves, are typically "collisionless", because the thickness of their jump region is much shorter than the collisional mean free path. Across…

Plasma-impurity reaction rates are a crucial part of modelling tokamak scrape-off layer (SOL) plasmas. To avoid calculating the full set of rates for the large number of important processes involved, a set of effective rates are typically…

Plasma Physics · Physics 2024-10-02 Dominic Power , Stefan Mijin , Kevin Verhaegh , Fulvio Militello , Robert J. Kingham

The slowing down of a charged particle beam passing through the dusty plasma with a non-thermal velocity alpha-distribution is studied. By using the Fokker-Planck collision theory, we derive the deceleration factor and slowing down time and…

Plasma Physics · Physics 2023-09-29 Yu Wang , Jiulin Du
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