Prospects of the gas-discharge EUV source based on the plasma creation by powerful pulsed terahertz gyrotrons

Abstract

Previous experiments performed in IAP RAS showed the possibility of realizing a localized (characteristic size not more than 1 mm in diameter) discharge in an inhomogeneous gas flow by focused sub-terahertz radiation beam. Plasma with an overcritical density up to 3·1016 cm - 3 was obtained. In these experiments, discharge glow was observed both in the range of vacuum (VUV) and extreme (EUV) ultraviolet. The performed experiments demonstrated that in order to increase the yield of EUV, the shorter wavelengths of heating radiation must be used. According to estimations, if the 1 THz radiation with power of several kilowatts is in a good coupling with the plasma, the plasma density will substantially exceed 1016 cm - 3 with electron temperature of the level of 50 eV. This should provide extreme ultraviolet glow of the discharge with power of about 100 W in the range 13-17 nm for xenon.