Generation efficiency and radiation stability of multiwave Cerenkov generators

Relativistic electron beams - electromagnetic field interaction regimes in a 3-cm wavelength range multiwave Cerenkov generators (MWCG) have been investigated both theoretically and experimentally. The influence of the drift tube length, magnetic field value and hollow electron beam diameter on the efficiency, stability, wavelength, spatial-temporal structure and temporal dynamics of radiation spectrum in MWCG with a two-sectional slow-wave structure (SWS) has been studied. The stable generation regimes with generation efficiency up to 10% have been found. Optimization of a beam-field interaction in MWCG with a three-sectional SWS allowed to increase the radiation efficiency up to 25%.