Results of blowout regime propagation experiments of an electron beam in a plasma

Short intense relativistic bunches, of the kind available from RF photoinjectors, have been observed, through integrated and time-dependent imaging, as well as collimator transmission, to effectively self-guide in an underdense plasma over many times the initial /spl beta/-function. Picosecond resolution measurement of transverse beam size displays the trumpet-shaped beam head predicted by simulations and analysis. The simulations are in good quantitative agreement with the beam sizes and transmissions obtained from experiment, with deviations arising from the approximations involved in the simulation model of the beam.