Measurements of energetic electrons and protons produced by a petawatt scale laser

The work reports on the measurement of energetic electrons produced by focusing the Vulcan petawatt pulse onto the edge of a supersonic gas jet. During the experiment, the laser consistently produced 650 fs duration pulses delivering /spl sim/ 180 J on target and generating intensities greater than 3 /spl times/ 10/sup 20/ W/cm/sup -2/. Ion acceleration from the interaction of the laser pulse with a underdense plasma using a laser power 1000 times the critical power is also performed for the occurrence of relativistic self-focusing. Strong correlation between maximum ion energy vs. plasma density is found which is also confirmed by simulations.