Fermi acceleration in relativistic collisionless plasma shocks correlates with anisotropic energy gains
Abstract
Collisionless shocks generated by two colliding relativistic electron-positron plasma shells are studied using particle-in-cell simulations. Shocks are mediated by the Weibel instability (WI), and the kinetic energy of the fastest accelerated particles is found to be anisotropically modified by WI-induced electric fields. Specifically, we show that all particles interacting with the shock bifurcate into two groups based on their final relativistic Lorentz factor γ: slow (γ<γbf) and fast (γ>γbf), where γbf is the bifurcation Lorentz factor that was found to be approximately twice the initial (upstream) Lorentz factor γ0. We have found that the kinetic energies of the slow particles are equally affected by the longitudinal and transverse components of the shock electric field, whereas the fast particles are primarily accelerated by the transverse field component.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 01, 2021
- Source ID
- 10.1063/5.0061083
Entities
People
- Gennady Shvets
- Roopendra Singh Rajawat
- Vladimir Khudik
Organizations
- Cornell University
- United States Department of Energy
- University of Texas at Austin