A large-dynamic-range high-time-resolved transmission grating spectrometer for the measurement of broadband x-ray spectrum.

The temporal measurement of broadband x-ray spectrum is important for the study of x-ray sources and their applications in high-energy-density plasmas. A spectrometer with a large dynamic range is required for these measurements. In this paper, a large-dynamic-range x-ray spectrometer has been designed, in which transmission grating is coupled to an x-ray streak camera with a novel varying-width slit photocathode. Compared to a traditional fixed-width slit photocathode, the dynamic range of the spectrometer has been increased by a factor of 23. The spectral range of the spectrometer is 0.12-6.2 keV, and the temporal resolution is 40 ps. This spectrometer would be a powerful diagnostic tool for hohlraum radiation characterization and radiative ablation in inertial confinement fusion.