Beam-beam interactions in concentric-beam dual-mode TWT´s

A new approach to dual mode technology will be presented in this paper. The device, presently under development for AFAL under Contract No. F33615-79-C-1863 uses a low voltage solid C.W. beam and a high voltage hollow pulse beam. The C.W. beam is continuously used within a PPM structure to generate C.W. power and its space charge is used to stabilize a higher voltage hollow beam injected around the solid beam during pulse operation. This paper presents beam-beam, beam-helix and beam-helix-beam interactions studies for various operating parameters and discusses significant phenomena, such as Kompfner dip and double-beam amplification. A final gun design for creating concentric beams is also discussed.