We describe how active feedback routines can be applied at limited repetition rate (5 Hz) to optimize high-
power (
P>
10 TW) laser interactions with clustered gases. Optimization of x-ray production from an
argon cluster jet, using a genetic algorithm, approximately doubled the measured energy through temporal
modification of the 150 mJ driving laser pulse. This approach achieved an increased radiation yield through
exploration of a multi-dimensional parameter space, without requiring detailed
apriori
knowledge of the
complex cluster dynamics. The optimized laser pulses exhibited a slow rising edge to the intensity profile,
which enhanced the laser energy coupling into the cluster medium, compared to the optimally compressed
FWHM pulse (40 fs). Our work suggests that this technique can be more widely utilized for control of intense
pulsed secondary radiation from petawatt-class laser systems.