Interaction between laser pulses and trailing wakefields intersecting at small angle for LWFA charge yield enhancement

Increasing the high energy electron yield from laser wakefield acceleration is crucial to its development as an electron beam source. We present a scheme for charge yield enhancement using two equal-intensity pulses—or hot spots in a single laser pulse—intersecting at a small angle. Experiments on the Texas Petawatt Laser with two well-defined hot spots yielded more than ten times as much charge as the single-hot-spot case. VORPAL particle-in-cell simulations suggest the charge yield enhancement depends on the hot-spot intersection angle and the relative phase between spots.