Field Ionization using a 28.5 GeV Electron Beam

The E164/E164X plasma wakefield experiment studies beam-plasma interactions at the Stanford Linear Accelera- tion Center (SLAC). Due to SLAC's recent ability to vari- ably compress bunches longitudinally from 650 µm down to 20 µm, the incoming beam is sufficiently dense to field ionize the neutral lithium (Li) vapor. The field ionization effects are characterized by the beams energy loss through the Li vapor column. Experiment results are presented.