3D Metallic Lattices for Accelerator Applications

We present the results of our recent research on 3D metallic lattices operating at microwave frequencies, with applications to advanced accelerating structures, radiation sources based on the Smith-Purcell (SP) effect, and SP-based microbunch diagnostics. Electromagnetic waves in a simple 3D cubic lattice formed by metal wires are investigated using HFSS. The bulk modes in the lattice are determined using single cell calculations, with phase advances in all three directions. The Brillouin diagram for the bulk modes of the cubic wire lattice is calculated. The recently predicted "plasmon" and "photon" modes are identified in the simulations. Surface modes at the vacuum/wire lattice interface are identified, and their dispersion relation (the frequency vs. the wave number along the interface) is studied. The surface mode profiles clearly demonstrate that the wire lattice acts as a negative dielectric constant material.