Novel diagnostic method for high-Z laser-produced plasmas based on discrete spectral characteristics of low-Z ions

Diagnosing the state of high-Z laser-produced plasma is challenging because of the narrow-band or quasi-continuous nature of radiation in the extreme ultraviolet region. This paper presents an innovative method that introduces discrete characteristic lines by doping with low-Z ions, using these lines to diagnose the state parameters of high-Z laser-produced plasmas. In the spectral simulation, the spatial distribution of plasma state parameters is assumed to follow a Gaussian distribution, and the radiation intensity of the spectrum is obtained by solving the radiative transfer equation along a single ray path. The method is benchmarked by analyzing the temporal evolution behavior of laser-produced plasma in an Al-Sn alloy. Finally, the effects of the doping ratio on the spectral profile and radiation energy within a 2% bandwidth around 13.5 nm are analyzed.