Bessel (Axicon) beams and laser driven accelerators

Summary form only given, as follows. Analyses of high gradient acceleration schemes utilizing intense electromagnetic waves generally employ Gaussian laser beams. This is natural since the output from a laser cavity is nearly Gaussian, which can be readily focused to a tight spot with high intensity. There are, however, other beam profiles that can be generated with relative ease and may be more advantageous than Gaussian beams, as determined by the acceleration gradient or the energy gain. Examples of these beams include Bessel and axicon beams. We shall present a comparison of Bessel and Gaussian beams for several advanced accelerator schemes.