Formation of a self-magnetic cusp in a highly bunched relativistic annular electron beam

Abstract

The formation of a self-magnetic cusp that develops in a highly bunched, relativistic, annular electron beam as the beam current approaches a critical current limit is demonstrated. The self-magnetic cusp is calculated within the framework of a fluid equilibrium model for a beam of periodic, azimuthally symmetric, relativistic bunched annular disks propagating in a perfectly conducting cylindrical pipe with a uniform magnetic focusing field. Magnetic cusp formation may play an important role in determining the operational current limit of high-current bunched relativistic annular beam experiments.