Simplified nonlinear theory of the dielectric loaded rectangular Cerenkov maser

Abstract

To rapidly and accurately investigate the performance of the dielectric loaded rectangular Cerenkov maser, a simplified nonlinear theory is proposed, in which the variations of wave amplitude and wave phase are determined by two coupled first-order differential equations. Through combining with the relativistic equation of motion and adopting the forward wave assumption, the evolutions of the forward wave power, the power growth rate, the axial wave number, the accumulated phase offset, and the information of the particle movement can be obtained in a single-pass calculation. For an illustrative example, this method is used to study the influences of the beam current, the gap distance between the beam and the dielectric surface, and the momentum spread on the forward wave. The variations of the saturated power and the saturation length with the working frequency for the beams with different momentum spreads have also been studied. The result shows that the beam—wave interaction is very sensitive to the electron beam state. To further verify this simplified theory, a comparison with the result produced from a rigorous method is also provided, we find that the evolution curves of the forward wave power predicted by the two methods exhibit excellent agreement. In practical applications, the developed theory can be used for the design and analysis of the rectangular Cerenkov maser.

Analogy Between Circular Core-Cladding and Impedance Waveguides and Their Membrane Functions

“…Alternatively, the hybridization parameter is found from Eqs. (13) and (27). We equate these alternative expressions of hybridization parameter and thus obtain…”

“…In this case, extra condition similar to Eq. (27) should be imposed on the field at the outer boundary of the waveguide.…”

“…Among other applications, dielectric-loaded waveguides have found applications in gyro-devices including gyrotron [2][3][4], gyro-TWT [5][6][7][8][9][10][11][12][13], CARM [14] and others [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. The gyro-devices usually employ RF structures with small structural nonuniformities.…”