A Lagrangian compatible radiation hydrodynamic algorithm and the nuclear dynamics computing module are developed and implemented in the LARED Integration code, which is a radiation hydrodynamic code based on the 2-D cylindrical coordinates for the numerical simulation of the indirect-drive Inertial Confined Fusion. A number of 1-D and 2-D ignition implosion numerical simulations by using the improved LARED Integration code (ILARED) are presented which show that the 1-D numerical results are consistent with those computed by the 1-D radiation hydrodynamic code RDMG, while the simulation results of the 2-D low-mode radiative asymmetry and hydrodynamic instability growth, according to the physical analysis and anticipation, are satisfactory. The capsules driven by the sources from SGII experiments are also simulated by ILARED, and the fuel shapes agree well with the experimental results. The numerical simulations demonstrate that ILARED can be used in the simulation of the 1-D and 2-D ignition capsule implosion using the multi-group diffusion model for radiation.

A study is conducted using a two-dimensional simulation program (Lared-s) with the goal of developing a technique to evaluate the effect of Rayleigh-Taylor growth in a neutron fusion reaction region. Two peaks of fusion reaction rate are simulated by using a two-dimensional simulation program (Lared-s) and confirmed by the experimental results. A neutron temporal diagnostic (NTD) system is developed with a high temporal resolution of ∼ 30 ps at the Shen Guang-III (SG-III) prototype laser facility in China, to measure the fusion reaction rate history. With the shape of neutron reaction rate curve and the spherical harmonic function in this paper, the degree of Rayleigh-Taylor growth and the main source of the neutron yield in our experiment can be estimated qualitatively. This technique, including the diagnostic system and the simulation program, may provide important information for obtaining a higher neutron yield in implosion experiments of inertial confinement fusion.

The first shaped-pulse inertial confinement fusion implosion experiments of the deuterium-deuterium (DD) gas-filled plastic (CH) capsules have been done at the SG-III laser facility [He and Zhang, Eur. Phys. J. D 44, 227 (2007); Zheng et al., Matter Radiat. Extremes 2, 243 (2017)]. The measured neutron yield is much lower than that predicted by one-dimensional (1D) simulations, and as the trough duration of the drive source increases, the neutron yield over clean decreases rapidly to less than 1%. To understand the primary reason for this decrease in yield, we numerically simulated the capsule implosion to investigate the effects of the support tent and the various capsule-surface defects on the implosion performance. The validity of the underlying 1D model is supported by the agreement between the results of the 1D simulation and experimental data for the implosion trajectory and fuel areal density. Compared with square-pulse implosions, shaped-pulse implosions exhibit a much larger growth in hydrodynamic instabilities. The numerical neutron yields of the shaped-pulse implosions are much more sensitive to perturbations seeded by inward-facing divots on the outer ablator surface. Yield degradation is mainly caused by a reduction in mechanical power exerted by the distorted shell on the central DD gas, which significantly lowers the fuel temperature and pressure.

In proton radiography, degeneracy of electric and magnetic fields in deflecting the probe protons can prevent full interpretation of proton flux perturbations in the detection plane. In this paper, theoretical analyses and numerical simulations suggest that the contributions of the electric and magnetic fields can be separately obtained by analyzing the difference between the flux distributions of two discriminated proton energies in a single shot of proton radiography. To eliminate the influence of field evolution on the separation, a strategy is proposed in which slow field evolution is assumed or an approximate estimate of field growth is made. This could help achieve a clearer understanding of the radiographic process and allow further quantitative analysis.

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