Mechanisms of an electron stream self-bunching in magnetron guns

Various processes of self-bunching of reentrant electron cloud nearby a distributed cylindrical cathode in crossed fields are investigated theoretically using particle-in-cell (PIC) simulation algorithms. As most probable mechanisms of formation of an azimuthally heterogeneous electron beam, tangential eigenmodes (i.e., natural tangential oscillations) of the electron cloud, secondary-emission bunching of one and true solitons generation in the beam are considered and compared. Illustrations of all just listed bunches as well as of some other turbulence phenomena at the electron hub are given, and their possible influence on the magnetron guns performance is discussed