Numerical solution of exact axial magnetic field for planar and cylindrical beam driven backward wave oscillator

Summary form only given. In this paper numerical solution of exact magnetic field for planar and cylindrical beam driven backward wave oscillator is carried out at π point. Our results show that for beam parameters V_b=5.32×10⁸ cm s^-1, relativistic factor γ=1.16, and beam voltage = 80kv, nearly 7kG magnetic field is required to focus both electron beam at π point. We obtain the comparable enhancement in the growth rate of planar beam driven backward wave oscillator as compared to that of cylindrical beam.