Dissertation/Thesis Abstract

Theoretical and Observational Analysis of Particle Acceleration Mechanisms at Astrophysical Shocks
by Lever, Edward Lawrence, Ph.D., University of California, San Diego, 2011, 405; 3454327
Abstract (Summary)

We analytically and numerically investigate the viability of Shock Surfing as a pre-injection mechanism for Diffusive Shock Acceleration, believed to be responsible for the production of Cosmic Rays. We demonstrate mathematically and from computer simulations that four critical conditions must be satisfied for Shock Surfing to function; the shock ramp must be narrow, the shock front must be smooth, the magnetic field angle must be very nearly perpendicular and, finally, these conditions must persist without interruption over substantial time periods and spatial scales. We quantify these necessary conditions, exhibit predictive functions for velocity maxima and accelerated ion fluxes based on observable shock parameters, and show unequivocally from current observational evidence that all of these necessary conditions are violated at shocks within the heliosphere, at the heliospheric Termination Shock, and also at Supernovae.

Indexing (document details)
Advisor: Griest, Kim, Quest, Kevin B.
Commitee: Coles, William A., Diamond, Patrick H., Griest, Kim, O'Neil, Thomas M., Quest, Kevin B., Rothschild, Richard E.
School: University of California, San Diego
Department: Physics
School Location: United States -- California
Source: DAI-B 72/07, Dissertation Abstracts International
Subjects: Astrophysics, Astronomy, Plasma physics
Keywords: Astrophysical shocks, Heliosphere, Particle acceleration, Shock surfing, Velocity diffusion
Publication Number: 3454327
ISBN: 9781124633695