Dynamics of a multi-beam photonic free electron laser

A photonic free-electron laser (pFEL) uses free electrons streaming through a photonic crystal (PhC) to generate tunable coherent radiation. Here, we consider a pFEL driven by a set of three low energy (~ 10 keV), low perveance (< 0.1 μP) electron beams. Using a particle-in- cell code, we numerically study the dynamics and calculate the small-signal growth rate and output power of the various modes. We show that for an appropriate design of the PhC and selective placement of the electron beams, single mode operation is possible. We will also present results on the scaling with the number of electron beams