1. A method of generating EUV radiation in a radiation source for a lithographic apparatus, the method comprising:
supplying a stream of fuel droplets to a target area;
configuring a laser to emit pulses of laser radiation directed at said target area timed to strike and vaporize a fuel droplet
to generate EUV radiation; and
predicting a delay caused by the effect of vaporization of one fuel droplet on a subsequent fuel droplet in said stream; and
controlling the timing of said pulses to be dependent on the predicted delay caused by the effect of the vaporization.