Angle-resolved absolute out-of-band radiation studies of a tin-based laser-produced plasma source

Out-of-band radiation emitted from an extreme ultraviolet laser-produced plasma, formed on a solid tin target, was measured over several angles between 25° and 85° with respect to the target normal for six energy bands between 200 and 1000 nm. The optical and target system was rotated with respect to the detector and the intensity of the radiation was measured using an absolutely calibrated filter/photodiode combination. The emission was dominated by radiation in the 214 nm band. A cosine function fitted to the angular distribution of the total radiation yielded an exponent of 0.23±0.02.