Beatwave acceleration of 12 MeV electrons to 50 MeV using shaped CO/sub 2/ laser pulses

A plasma heatwave accelerator with a gradient /spl sim/1.3 GeV/m is presented. It is shown that for diffraction limited plasmas, when efficiency of the plasma wave excitation is restricted by ionization-induced refraction, acceleration of electrons is enhanced by using asymmetric, long pulses.