[Table of Contents]

Plasma and Fusion Research

Volume 6, 2401025 (2011)

Regular Articles

Effect of Magnetic-Field Gradient on Positron Acceleration along the Magnetic Field in an Oblique Shock Wave
Takashi IWATA, Seiichi TAKAHASHI and Yukiharu OHSAWA
Department of Physics, Nagoya University, Nagoya 464-8602, Japan
(Received 3 December 2010 / Accepted 11 January 2011 / Published 1 July 2011)


Ultrarelativistic positron acceleration along the magnetic field due to shock waves in an electron-positron-ion plasma is studied with use of one-dimension (one space coordinate and three velocities), fully kinetic, fully electromagnetic, particle simulations. First, ultrarelativistic acceleration to γ ∼ 104 in a uniform external magnetic field B0 is demonstrated with a simulation with the shock speed vsh close to c cos θ, where c is the speed of light and θ is the angle between the external magnetic field and the wave normal. Then, the effect of non-uniformity of B0 is investigated; comparisons are made of two different cases: 1) the strength of the external magnetic field increases as a shock wave propagates (∇B0 is parallel to the wave normal), and 2) it decreases (∇B0 is unti-parallel to the wave normal). It is found that positron acceleration in the latter tends to be stronger than in the former.


ultrarelativistic positron acceleration, electron-positron-ion plasma, magnetosonic shock wave, parallel electric field, particle simulation

DOI: 10.1585/pfr.6.2401025


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This paper may be cited as follows:

Takashi IWATA, Seiichi TAKAHASHI and Yukiharu OHSAWA, Plasma Fusion Res. 6, 2401025 (2011).