Experimental investigation of titanium hohlraum as intense multi-keV X-ray source

The titanium hohlraum as a bright X-ray source was explored on the Shenguang-Ⅲ prototype laser facility. It shows that the multi-keV X-rays are mainly generated near the cylinder axis. The multi-keV X-ray emission region and the duration increase with the increase of the hohlraum inner diameter, but the X-ray flux decreases, thus the optimal hohlraum inner diameter is in the range of 1000-1300 m for Shenguang-Ⅲ prototype laser facility. The presence of the bottom foil for the hohlraum can enhance the X-ray emission. The maximum X-ray conversion efficiency of the titanium hohlraums is 4.7% in 4 space, which is larger than that of the solid planar target.