Approximate analytical solution to the problem of the formation of a relativistic electron beam in a coaxial diode for different insulating magnetic fields

A theoretical study is made of the formation of a polyhelical electron beam in a magnetically insulated coaxial diode for different insulating fields. Electron motion is analyzed on the basis of a modified averaging method which takes into account the relativistic nature of the beam and the substantial transverse drift. The transformation of the beam structure in the acceleration region is explained, and the parameters of the formed beam are calculated for different external magnetic fields.