Evolution of the micropulse structure of an electron beam propagating in air

As part of the Air Force Research Laboratory's ongoing research in particle accelerators and beams, we have been investigating the propagation of electron beams of intermediate energy (1-100 MeV) in air. Of interest are the formation of the radiation shower and the detailed structure of the micropulses when the beams are produced by microwave linear accelerators. The experimental measurements and the supporting numerical simulations reported here indicate that the micropulse structure of the beam is well-preserved, even in the case of rather severe energy straggling and multiple scattering.