I will present a transformative route to obtain mass-producible helical slow-wave structures for operation in beam-wave interaction devices at millimeter-through-THz frequencies. The approach relies on guided self-assembly of conductive nanomembranes. The work coordinates simulations of cold helices (i.e., helices with no electron beam) and hot helices (i.e., helices that interact with an electron beam). The theoretical study determines electromagnetic fields, current distributions, and beam-wave interaction in a parameter space that has not been explored before.  These parameters include microscale diameter, pitch, tape width, and nanoscale surface finish. Informed by the simulation results, we design and fabricate prototype helices for operation as slow-wave structures at millimeter-through-THz frequencies, using metal nanomembranes. The nanomembrane stiffness and built-in stress control the diameter of the helices. The in-plane geometry of the nanomembrane determines the pitch, the chirality, and the formation of single vs. intertwined double helices..

Biography: