Cosmic ray acceleration in supernova remnant shocks

The long held belief that supernova remnants (SNRs) produce the majority of galactic cosmic rays remains unproven. If efficient diffusive shock acceleration is occurring in young SNRs, it will leave distinct morphological and spectral signatures observable with current radio, X-ray, and possibly gamma-ray observatories. We give a brief review of the nonlinear theory of diffusive shock acceleration, describe a simplified model of SNR structure and evolution which combines a hydrodynamic simulation with particle acceleration, and discuss some recent observations which may indicate the presence of the efficient production of cosmic ray ions.