Density diagnosis based on ps-duration-pulse X-ray backlighting for fast ignition compression

To provide significant parameters for fast ignition coupling efficiency and density diagnosis for higher compression, a ps-duration X-ray backlighter has been produced with ps-duration laser on Shenguang-Ⅱ updated facility. The radiation properties such as backlighting image resolution and the photons arriving at the image plate have been successfully measured. Based on the conformed conditions, density diagnosis of an indirectly-driven fast ignition target using ps-duration backlighting has been carried out. The obtained short-pulse backlighting radiography shows that the imploded shell shape agrees well with that of simulation and the areal density exceeds 50 mg/cm2. The short-pulse backlighting radiography also shows the hydrodynamic instability which might be caused by the asymmetric compression. Further investigations and attempts to improve implosion performance to a higher density are in progress.