Optical systems for laser-produced plasma EUV and soft X-ray sources

摘要

Laser-produced plasmas (LPP) are efficient sources of soft X-ray (SXR) and extreme ultraviolet (EUV) radiation. The emitted radiation can be collected and focused using grazing incidence or multilayer mirrors. This way radiation beams of high fluence can be formed. Their interaction with gases results in formation of photoionized plasmas of different parameters, depending on the fluence and properties of the gas. In this work LPP SXR and EUV sources, based on nanosecond Nd:YAG lasers and a double stream gas puff target are described. Parameters of the radiation pulses focused using the corresponding collectors, were measured. The sources were used for creation of the EUV induced, low-temperature plasmas. For measurements of the weak EUV emission signals from these plasmas, a special detection system, containing a paraboloidal collector, was prepared. Time integrated, EUV intensity distribution in a focal spot of the collector, was measured using a back-illuminated CCD detector. Temporal measurements of the EUV signals were performed employing an AXUV photodiode mounted in the focal plane.