Experiments in nonperturbative electron beam characterization with the MIT microwiggler at the accelerator test facility at BNL

We report first measurements of a single-shot method through which the properties of an electron beam at linac energies may be studied using the spontaneous emission of a micro-wiggler. The setup is simple and the measurement efficient. A simple set of scaling laws describe the natural line width, energy spread and divergence broadening of spontaneous emission in a narrow bandwidth radiation cone. A systematic series of experiments were performed with the MIT Microwiggler at the Accelerator Test Facility at BNL which demonstrated the response of the cone to changes in the beam quality. Estimates of divergence were obtained from the measurements of the radiation cone.