Irradiation characteristics of laser quads on cylindrical hohlraum wall in indirec-drive facility

In indirec-drive inertial confinement fusion facilities, aimed at the cylindrical hohlraum with two cones of laser quads and the laser quads configuration, the propagation model of laser quads in the cylindrical hohlraum was built up based on the beam smoothing schemes. On the basis, the irradiation characteristics of laser quads on vacuum cylindrical hohlraum wall were analyzed, and the laser quads arrangement was optimized preliminarily according to all the spots arrangement on hohlraum wall. Results indicate that, with the increasing of the incident angle of laser quads, the spot size of laser quads on hohlraum wall decreases, while the fractional hot spot has no significant change, and the polarization characteristics also remain almost unchanged. By further analysis of the intensity distribution and fractional hot spot of all the laser quads on hohlraum wall, it indicates that the overlap of the inner and outer cones on the hohlraum wall increases the peak intensity and raises the proportion of the hot spot in relevant area. By appropriate adjustment of the location of the focal plane and the incident angle of the inner cone laser quads, the irradiation characteristics of all the laser quads on hohlraum wall may be improved.