Indirect Drive Icf Radiation Drive Symmetry

A good radiation-driven symmetry is important for indirectly driven inertial confinement fusion (ICF) laboratory. It achieve ignition and high gain which is essential for precise regulation of the symmetry of the experimental environment. The main research content of this article are as follows.1. A view-factor method for calculating radiation drive from hohlraum walls to the capsule in indirect ICF is presented, with which asymmetry conditions for implosion experiments on SG-III prototype were evaluated. We calculated X-ray intensity distribution on the hohlraum walls and radiation drive on the capsule located in the center of cylindrical gold target. The driven nonuniformity varying with the laser-spot locus and the hohlraum geometry were also given. The results showed that this method helps to assess the main parameters of indirect ICF targets and provides useful information for experiment design.2. Measurement of radiation field near a implosion pellet M band X-ray is a important area in ICF research. On the"SG II"laser facility, M band X-ray from Au plasma was measured in half hohlraum radiation from the end. The experiment set-up and typical result were given. And we've also used View-factor program to simulate this experiment. The results indicate that angular distribution of M band X-ray from the end of half hohlraum doesn't assume linear relationship with the cosine of eradiating angle. The results are useful for the research of implosion experiment and target design.3. In order to meet the requirement of symmetry tuning and measurement in implosion experiment, a image processing method has been adopted. This method is based on Legendre fit, with the theory of radiation drive symmetry,which help the analysis of compressed core image. Through a series of data analysis, a detailed comparison of two methods has been processed. The result showed the error of the new method is smaller than that of the current applied image processing method, and the new method gets more high modes details (neglected in the past).