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We present a new experimental method to generate quasi-perpendicular supercritical magnetized collisionless shocks. In our experiment, ambient nitrogen (N) plasma is at rest and well-magnetized, and it has uniform mass density. The plasma…

In a dusty plasma, an impulsively generated shock, i.e., blast wave, was observed to decay less than would be expected due to gas friction alone. In the experiment, a single layer of microparticles was levitated in a radio-frequency…

Plasma Physics · Physics 2020-12-02 Anton Kananovich , J. Goree

We model relativistically colliding plasma by PIC simulations in one and two spatial dimensions, taking an ion-to-electron mass ratio of 400. Energy dissipation by a wave precursor of mixed polarity and different densities of the colliding…

Astrophysics · Physics 2009-11-13 M. E. Dieckmann , P. K. Shukla , L. O. C. Drury

Collisionless shock acceleration of protons and C$^{6+}$ ions has been achieved by the interaction of a 10$^{20}$ W/cm$^2$, 1 $\mu$m laser with a near-critical density plasma. Ablation of the initially solid density target by a secondary…

lasma instabilities excited in collisionless shocks are responsible for particle acceleration. We have investigated the particle acceleration and shock structure associated with an unmagnetized relativistic electron-positron jet propagating…

High Energy Astrophysical Phenomena · Physics 2015-06-03 K. -I. Nishikawa , E. J. Choi , K. Min , P. Hardee , Y. Mizuno , B. Zhang , J. Niemiec , M. Medvedev , A. Nordlund , J. Fredriksen , M. Pohl , H. Sol , D. H. Hartmann , G. J. Fishman

Collisionless Larmor coupling is a fundamental process in space and astrophysical plasmas that enables momentum transfer between an expanding plasma and a magnetized ambient medium. In this paper, we report on the laboratory experimental…

The expansion of a dense plasma into a dilute plasma across an initially uniform perpendicular magnetic field is followed with a one-dimensional particle-in-cell (PIC) simulation over MHD time scales. The dense plasma expands in the form of…

Plasma Physics · Physics 2018-05-30 M E Dieckmann , D Folini , R Walder , L Romagnani , E d'Humieres , A Bret , T Karlsson , A Ynnerman

In this work, we investigate collisionless shocks propagating in a relativistically hot unmagnetized electron-positron plasmas. We estimate the dissipation fraction at shocks in the relativistically hot plasma, showing that it is…

High Energy Astrophysical Phenomena · Physics 2024-10-21 Kamiido Kazuki , Ohira Yutaka

Hot-cold ablative mixing plasmas are ubiquitous in astrophysical and laboratory systems, where a cold/dense plasma is roughly in pressure balance with a hot/dilute plasma. Examples include the plasma thermal quench during major disruptions…

Plasma Physics · Physics 2025-04-01 Yanzeng Zhang , Xian-Zhu Tang

The collision of two plasma clouds at a speed that exceeds the ion acoustic speed can result in the formation of shocks. This phenomenon is observed not only in astrophysical scenarios such as the propagation of supernova remnant (SNR)…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Mark Eric Dieckmann , Gianluca Sarri , Domenico Doria , Hamad Ahmed , Marco Borghesi

We present the results of direct simulation of the expansionof a two-component ultracold plasmafor various numbers of particles, densities, and electron temperatures. A description of the expansionprocess common to all plasma parameters is…

Plasma Physics · Physics 2021-07-28 E. V. Vikhrov , S. Ya. Bronin , B. B. Zelener , B. V. Zelener

Plasma processes close to SNR shocks result in the amplification of magnetic fields and in the acceleration of electrons, injecting them into the diffusive acceleration mechanism. The acceleration of electrons and the B field amplification…

High Energy Astrophysical Phenomena · Physics 2015-06-09 M E Dieckmann , G Murphy , A Meli , L O C Drury

Collisionless shocks are ubiquitous in the Universe and are held responsible for the production of non-thermal particles and high-energy radiation. In the absence of particle collisions in the system, theoretical works show that the…

The expansion of a thermal pressure-driven radial blast shell into a dilute ambient plasma is examined with two-dimensional PIC simulations. The purpose is to determine if laminar shocks form in a collisionless plasma that resemble their…

Plasma Physics · Physics 2018-05-30 M E Dieckmann , Q Moreno , D Doria , L Romagnani , G Sarri , D Folini , R Walder , A Bret , E d'Humieres , M Borghesi

When the ions are accelerated by the radiation pressure of the laser pulse, their velocity can not exceed the laser group velocity, in the case when it is less than the speed of light in vacuum. This is demonstrated in two cases…

Two charge- and current neutral plasma beams are modelled with a one-dimensional PIC simulation. The beams are uniform and unbounded. The relative speed between both beams is 0.4c. One beam is composed of electrons and protons and one out…

Astrophysics · Physics 2014-11-18 M E Dieckmann , A Bret

Laser-induced water ablation triggers various physical effects, including atom ionization, optical breakdown of the liquid, phase explosion, cavitation, and shockwave propagation. These effects can be further amplified in heavy water by…

Plasma Physics · Physics 2024-09-06 Denys Moskal , Jiri Martan , Vladislav Lang , Milan Honner

We study, by numerical and analytical means, the evolution of a uniform one-dimensional collisionless plasma initiated between plane absorbing walls. The ensuing flow is described by rarefaction waves that propagate symmetrically inward…

Plasma Physics · Physics 2021-02-03 Alexander V. Khrabrov , Igor D. Kaganovich , Jian Chen , Heng Guo

Multi-dimensional particle-in-cell simulations are used to study the generation of electrostatic shocks in plasma and the reflection of background ions to produce high-quality and high-energy ion beams. Electrostatic shocks are driven by…

We analyze, in both plane and cylindrical geometries, a collisionless plasma consisting of an inner region where generation occurs by UV illumination, and an un-illuminated outer region with no generation. Ions generated in the inner region…

Plasma Physics · Physics 2014-01-28 R. N. Franklin , J. E. Allen , D. M. Thomas , M. S. Benilov