Magnetowave Induced Plasma Wakefield Acceleration for Ultra High
Energy Cosmic Rays

Pisin Chen

Kavli Institute for Particle Astrophysics and Cosmology
Stanford Linear Accelerator Center

Abstract: Magnetowave-induced plasma wakefield acceleration (MPFA) in a relativistic astrophysical outflow was proposed in 2002 as a viable mechanism for the acceleration of cosmic particles to ultra high energies. Recently our simulation results have clearly demonstrated the existence of the mechanism for the first time. Instead of relying on the lower frequency and speed Alfven limit of the magnetowave, we concentrate on its higher frequency and speed whistler mode as the regime for the driving pulse. The magnetized plasma wakefield so induced follows precisely the theoretical prediction. We show that when the condition is right, the plasma wakefield so induced maintains very high coherence and can thus sustain high-gradient acceleration for macroscopic distance. This mechanism provides a third option for exciting large amplitude plasma wakefield acceleration, in addition to that driven by a laser pulse or an electron beam. We discuss its connection to the production of ultra high energy cosmic rays (UHECR). Considering the inter-disciplinary nature of the subject, the talk will be pedagogical for audience with different backgrounds and will emphasize the plasma-astro connection.