The determination of absolutely calibrated spectra from laser produced plasmas using a transmission grating spectrometer at the Nike laser facility

A transmission grating spectrometer has been developed that is capable of r ecording time-resolved spectra from laser-irradiated target foils in the wa velength range from 10 to 150 Angstrom. Since the primary goal is to quanti fy the radiation flux from the resulting plasma, a detailed investigation h as been conducted to evaluate the estimation of the absolute radiation inte nsity. Time-integrated spectra were observed on photographic film using a 5 000 l/mm grating and clearly show the superposition of four diffraction ord ers. The deconvolution of the observed spectrum is based on a quantitative description of the spectrometer's performance using the calibrated transmis sion efficiencies of the grating's diffraction orders. This deconvolution p rocedure can provide an estimate of the absolute spectral intensity with a residual error of similar to 20%. Results from a high spectral resolution g razing-incidence spectrometer have been used in the development of this met hod. A streak camera (not absolutely calibrated) was also used with the tra nsmission grating spectrometer to record the time-resolved spectra. (C) 200 1 American Institute of Physics.