Speaker
Description
Two dimensional (2D) periodic surface lattices PSLs have been used successfully in both fast-wave sources [1] and in slow-wave sources [2-4]. Numerical simulation codes have been used to design an electron beam driven W-band millimeter-wave source, in which a cylindrical two dimensional (2D) periodic surface lattice (PSL) forms an over-sized mode-selective cavity. The 2D PSL consists of shallow periodic cosinusoidal perturbations in both the azimuthal and axial directions on the inner wall of a cylindrical waveguide. Electrochemical deposition of copper on a cylindrical aluminum former with the aluminum subsequently removed by dissolving in strong alkali solution was used to construct the 2D PSL. Analytical theory and numerical PIC simulations have been used to design the W-band oscillator that has been constructed. The ratio of the diameter of the cylindrical cross-section of the structure to the operating wavelength is ~5. The performance of oscillator will be compared with the predictions of the numerical simulations.
ACKNOWLEDGMENT
Support from AFOSR under awards FA8555-13-1-2132 and FA9550-17-1-0095 is gratefully acknowledged.
REFERENCES
[1] N. S. Ginzburg, N. Y. Peskov, A. S. Sergeev, et al. , “Theory of free-electron maser with two-dimensional feedback driven by an annular electron beam”, J. Appl. Phys., vol. 92, pp. 1619-1629, Aug. 2002.
[2] A. W. Cross, I. V. Konoplev, A. D. R. Phelps, and K. Ronald, “Studies of surface two-dimensional photonic band-gap structures”, J. Appl. Phys., vol. 93, pp. 2208-2218, Feb. 2003.
[3] N. S. Ginzburg, E. V. Ilyakov, et al., “Theoretical and experimental studies of relativistic oversized Ka-band surface-wave oscillator based on 2D periodical corrugated structure”, Phys. Rev. Accel. Beams, vol. 21, (8), art. no. 080701, Aug. 2018.
[4] A.J, MacLachlan, C.W. Robertson, I.V. Konoplev, A.W. Cross, A.D.R. Phelps and K. Ronald, ‘Resonant Excitation of Volume and Surface Fields on Complex Electrodynamic Surfaces’, accepted for Phys. Rev. Appl., Feb 2019.
