[P-EM17] Space Plasma Science

[PEM17-05] Magnetic Field Amplification by Ion-Weibel Instability in Astrophysical and Laboratory Plasmas

*Taiki Jikei¹, Takanobu Amano¹, Yosuke Matsumoto², Yasuhiro Kuramitsu³ (1.The University of Tokyo, 2.Chiba University, 3.Osaka University)

Keywords:Cosmic ray, Supernova remnant, Collisionless shocks, Laboratory astrophysics

It is known that astrophysical shocks accelerate cosmic rays efficiently. Non-relativistic, high Mach number shocks, such as supernova remnants (SNRs), are considered the primary source of galactic cosmic rays. In these shocks, ion-Weibel instability is thought to be the dominant plasma process responsible for magnetic field amplification and shock formation.
Using theory and particle-in-cell (PIC) simulations, we show that a weak but finite background magnetic field (MA~100) plays an essential role in enhanced magnetic field amplification and electron heating compared to unmagnetized (M_A>>1000) shocks. This electron heating may be relevant to the electron injection problem.
Although PIC simulation is a powerful tool for understanding plasma microphysics, reduced models in dimension, system size, and electron-to-ion mass ratio are used to save computational resources. We discuss possible laboratory laser experiment setups to verify the theory and simulation. Efficient magnetic field amplification using high-power lasers has applications outside astrophysics, such as medical treatment.