Persistent acceleration of positrons in a nonstationary shock wave

Journal Article · Mon Aug 15 04:00:00 EDT 2005 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.2009507· OSTI ID:20764458

Hasegawa, Hiroki; Kato, Ken; Ohsawa, Yukiharu ^[1]

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1. National Institute for Fusion Science, Toki 509-5292 (Japan)

Long-time evolution of positrons accelerated in an oblique shock wave in an electron-positron-ion plasma is studied with relativistic, electromagnetic, particle simulations. In the early stage, some positrons move nearly parallel to the external magnetic field in the shock transition region and gain energy from the parallel electric field. The acceleration can become stagnant owing to the deformation of the wave profile. After the recovery of the shock profile, however, the acceleration can start again. By the end of simulation runs, {omega}{sub pe}t=5000, positron Lorentz factors reached values {approx}2000. In this second stage, three different types of acceleration are found. In the first type, the acceleration process is the same as that in the early stage. In the second type, positrons make gyromotions in the wave frame and gain energy mainly from the perpendicular electric field. In the third type, particle orbits are similar to curtate cycloids. Theoretical estimate for this energy increase is given.

• OSTI ID: 20764458
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 8 Vol. 12; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ACCELERATION
DEFORMATION
ELECTRIC FIELDS
ELECTRONS
GAIN
IONS
MAGNETIC FIELDS
PLASMA GUNS
PLASMA SIMULATION
POSITRONS
RELATIVISTIC PLASMA
RELATIVISTIC RANGE
SHOCK WAVES