Gasdynamically-controlled dropets as the target in a laser-plasma extreme ultraviolet light source (EP)

A target material delivery system in the form of a nozzle for an EUV radiation source. The nozzle includes a target material supply line having an orifice through which droplets of a liquid target material are emitted, where the droplets have a predetermined size, speed and spacing therebetween. The droplets are mixed with a carrier gas in a mixing chamber enclosing the target material chamber and the mixture of the droplets and the carrier gas enter a drift tube from the mixing chamber. The droplets are emitted into an accelerator chamber from the drift tube where the speed of the droplets is increased to control the spacing therebetween. A vapor extractor can be mounted to the accelerator chamber or the drift tube to remove the carrier gas and target material vapor, which would otherwise adversely affect the EUV radiation generation