Development of soft X-ray transmission grating spectrograph and its spectrum unfolding techniques for ultrashort pulse laser produced plasma diagnosis

摘要

A normal incident, transmission grating spectrograph with enhanced collection efficiency and high spectral resolution has been developed for ultrashort pulsed laser produced plasma diagnosis with a high spectral resolution of Δλ≤0.05nm. The partial coherent diffraction theory is applied to determine the imaging characteristics of the spectrograph. Intensity distributions on the observation plane are given in closed form. A novel method of spectrum unfolding techniques is put forward. Computer simulation shows that this method can give an uncertainty of ≤0.5% when applied in the radiation temperature measurement in indirect driven ICF experiments.