We analyze non-physical solutions in laser ray tracing simulation.With a system of nonlinear equations,a new algorithm for intersection is presented.A special preconditioner is used to improve numerical stability.The algorithm is suitable for any intersectant condition.Numerical experiments show that the algorithm has better precision and adaptability.Simulation in LARED code shows good performance.

We introduce an ignition hohlraum 2D-simulation design method with 2D code.A design sequence,in which X-rays drive tempetature is tuned before P² asymmetry,is put forward.Details in designing laser power is studied.It indicates that control of P² asymmetry during trough pulse limits the maximum of filling gas density and expansion of capsule ablator can be restrained by longer drive pulse.An ignition hohlraum 2D-simulation design is given.

We give a convergence analysis on splitting iterative (SI) algorithm of multi-group radiation diffusion equations. Spectral radii of iterative matrix is shown. Numerical computation and analysis on spectral radii formulae reveal a relation between convergence rate and radiation coefficients. Numerical results confirm theoretical results, and give applicable conditions of the algorithm.

A series of exact solutions are constructed for two-dimensional radiative transfer and radiative diffusion problems with outer source.These solutions exhibt physical characteristics with simple expressions.Moreover,transport solutions degenerate directly into solutions of corresponding diffusion equations.Test results of the diffusion model with LARED-R are presented and analyzed.

Strong-coupled multigroup radiative transfer in optically thick regions are analyzed.A simple conner balance method in 2D is presented.A grey transport acceleration scheme is generalized to accelerate source iteration convergence of differenced multigroup transport equations.

We provide a radiant energy probing method based on single contour integration,including annulus probing and uniform probing.It probes the radiant field of an anisotropy light source and is used as an efficient visualization method.

Construction of difference schemes for parabolic equations on distorted meshes with large aspect ratio is discussed.The limitation of 9-point scheme is provided.An assistant mesh difference method is proposed for distorted meshes with large aspect ratio to improve precision and efficiency.Based on the conservation law,applying appropriate rezone methods for meshes we modify the 9-point method to reduce computation error due to poor regularity of the meshes and low precision due to the approximation to vertices values by an average of neighboring cell values.The nonlinear system obtained is a different system from the 9-point scheme.Its solution approximates to the solution with the original meshes.The designed scheme is implemented easily and adapts well to distorted meshes.Numerical experiments show good precision and stability.

Based on the theoretical study of spatial coherence of laboratory x-ray lasers, a principle setup is proposed for x-ray laser holography, and corresponding theoretical simulation is performed for the recording and reconstruction of the lenseless Fourier transform hologram.