  The nonresonant cosmic ray instability, predicted by Bell (2004), is thought
to play an important role in the acceleration and confinement of cosmic rays
(CRs) close to supernova remnants. Despite its importance, the exact mechanism
responsible for the saturation of the instability has not been determined, and
there is no first-principle prediction for the amplitude of the saturated
magnetic field. Using a survey of self-consistent kinetic hybrid simulations
(with kinetic ions and fluid electrons), we study the saturation of the
non-resonant streaming instability as a function of the parameters of both the
thermal background plasma and the CR population. The strength of the saturated
magnetic field has important implications for both CR acceleration in supernova
remnants and CR diffusion in the Galaxy.
