High-energy electron acceleration by ponderomotive forces in tenuous plasmas

Abstract
The results of an experimental study of electrons produced by multiphoton ionization of helium gas by intense 25‐psec‐duration pulses from a neodymium laser are reported. Electrons with energies up to 300 eV have been observed and both the maximum electron energy and the measured electron‐energy spectra are shown to be characteristic of electron acceleration by ponderomotive forces.