Development of a gated X-ray imager with multiple views and spectral selectivity for observing plasma evolution in hohlraums

In the study of indirect drive Inertial Confinement Fusion (ICF), X-ray images through the laser entrance hole of the hohlraums can provide key information. In this paper, we present the advances on the development of a gated X-ray imager with multiple views and spectral selectivity. A diagnostic snout which contains four X-ray planar mirrors has been designed and coupled to a gated X-ray detector which includes an air box and has a spatial resolution better than 35 µm and a temporal resolution better than 70 ps. The two inner mirrors in the diagnostic snout operate at M band (1.6-3.5 keV), while the two outer mirrors operate at N band (0.5-1 keV). The four mirrors define four observation angles. Each mirror can reflect 4 X-ray images to the four microstrips of the gated X-ray detector with almost the same observation angle. The imager enables us to observe the spatial and temporal evolution of plasma in the hohlraums from four different observation angles based on both N band and M band images. The imager has been used in the ICF experiments conducted at Shenguang laser facility in China, and the obtained X-ray images of Au cylindrical hohlraum are presented and discussed in this paper.