An overmoded W-Band source exploiting a periodic surface corrugation*

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 lattice¹ (PSL) forms an over-sized mode-selective cavity^2,3. Two manufacturing methods have been used. (1) Electrochemical deposition of copper on a cylindrical aluminum former with the aluminum subsequently removed by dissolving in strong alkali solution. (2) A 3D additive manufacturing (3D printing) technique resulting in a silver cylindrical 2D PSL.  An 80kV, ~100ns pulse duration electron beam guided by a 1.8T magnetic field was passed through the cylindrical 2D PSL cavity. Faraday cup, witness plate and current/voltage diagnostics have been used to characterize the electron beam and the mm-wave output has been measured. New results based on recent advances made in the design and operation of this experiment are presented.

1. AW Cross, IV Konoplev, ADR Phelps, et al., J. Appl. Phys., 93, pp. 2208-2218, 2003

2. IV Konoplev, AJ MacLachlan, CW Robertson, et al., Phys. Rev. A, 84, 013826, 2011

3. IV Konoplev, L Fisher, AW Cross, et al., Appl. Phys. Lett., 96, 261101, 2010