High brightness LPP EUV light source with fast rotating target and method of cooling thereof

A laser produced plasma (LPP) source for extreme ultraviolet (EUV) or vacuum ultraviolet (VUV) light, comprising:

• a vacuum chamber with a rotating target assembly having a rotation drive unit and a part made in a form of a disk with a barrier on an inner surface of which there is an annular groove with a target material supplied to an interaction zone with a focused beam of a high-repetition-rate pulsed laser, and a beam of EUV plasma light coming out from the interaction zone,
• wherein a heat exchanger with a liquid cooling is installed in the vacuum chamber, fixed relative to the vacuum chamber;
• and wherein a part of a heat exchanger surface is separated from the surface of the rotating target assembly disk by a slit gap or clearance,
• wherein the light source having an outer surface of a peripheral part of the rotating target assembly is made with a relatively large surface area S exceeding 0.5×R2, where R is a rotating target assembly outer radius, and wherein the outer surface has a coating with a relatively high emissivity of more than 0.7.