Proposal of the large orbit cyclotron autoresonance maser amplifier with an outer-slotted-coaxial structure

The linear kinetic theory and nonlinear self-consistent model for the outer-slotted-coaxial cyclotron autoresonance maser (CARM) amplifiers with axis-encircling beam are presented. Good agreement is found between the simulations and the kinetic theory in the linear regime. The choice of the electron beam current for suppressing the absolute instability is discussed. Using 700 kV, 100 A axis-encircling beam with the velocity pitch alpha= 0.8, the nonlinear self-consistent analysis of a TE₅₁ CARM amplifier predicts a peak output power of 6.27 MW and peak efficiency of 8.96%, which verifies that the large orbit outer-slotted-coaxial structure CARM would be expected to operate in millimeter and sub-millimeter wave band with high power, ultrahigh gain and low operating magnetic field,.