Stable transport and side-focusing of sheet electron beams in periodically cusped magnetic field configurations

Summary form only given, as follows. Sheet electron beams and configurations with multiple electron beams have the potential to make possible higher power sources of microwave radiation due to their ability to transport high currents, at reduced current densities, through a single narrow RF interaction circuit. Possible microwave device applications using sheet electron beams include sheet-beam klystrons, grating TWTs, and planar FELs. Historically, implementation of sheet beams in microwave devices has been discouraged by their susceptibility to the diocotron instability in solenoidal focusing systems. However, recent theoretical and numerical studies have shown that stable transport of sheet beams is possible in periodically cusped magnetic (PCM) fields. The use of an offset-pole PCM configuration has been shown analytically to provide side-fields for 2D focusing of the beam, and this has been recently verified with PIC code simulations. We will present further theoretical studies of sheet and multi-beam transport and discuss experimental measurements of an offset-pole PCM array which is currently being constructed.