Influence analysis of symmetry on capsule in six-cylinder-port hohlraum

We have investigated the flux symmetry on the capsule in a six-cylinder-port hohlraum for improving the design of the hohlraum. The influence factors of drive symmetry on the capsule in the hohlraum are studied, including laser power, laser beams arrangement, hohlraum geometric parameters, plasma condition, capsule convergence, etc. The x-ray radiation flux distribution on the capsule is obtained based on the three-dimensional view factor model. In the six-cylinder-port hohlraum, the main drive asymmetry is the C₄₀ mode asymmetry. When the C₄₀ mode asymmetry approaches zero, the drive symmetry on the capsule is optimal. Our results demonstrate that in order to have a high flux symmetry on the capsule in the laser main-pulse stage, more negative initial C₄₀ modes are needed, which can be realized by adjusting the hohlraum geometry parameters. The hohlraum with column length L_H=4.81 mm has an optimal symmetry in the laser main-pulse stage.