Xu Han

Simulation of the Quasi-Monoenergetic Protons Generation by Parallel Laser Pulses Interaction with Foils

A new scheme of radiation pressure acceleration for generating high-quality protons by using two overlapping-parallel laser pulses is proposed. Particle-in-cell simulation shows that the overlapping of two pulses with identical Gaussian profiles in space and trapezoidal profiles in the time domain can result in a composite light pulse with a spatial profile suitable for stable acceleration of protons to high energies. At ~2.46 × 1021 W/cm2 intensity of the combination light pulse, a quasi-monoenergetic proton beam with peak energy ~200 MeV/nucleon, energy spread <15%, and divergency angle <4° is obtained, which is appropriate for tumor therapy. The proton beam quality can be controlled by adjusting the incidence points of two laser pulses.

Parallel Solution Algorithm for the Multi-Group Particle Transport Equations on the Unstructured Meshes:

The numerical simulations for solving the transport equations lead to the large computation and need to implement parallel calculation. On the unstructured grids, the communicating delays, sorting algorithms and inserting algorithms limit the performance of current algorithms, which decrease the scalable parallel performance. This paper presents an effective way to implement the scalable parallel numerical simulation on the clusters by combining the energy groups and the space domain decomposition. Based on the list schedule, we first design a multi-group parallel method to solve the load unbalance problem which is brought about by the energy group parallel decomposition. After we describe the priority algorithm to arrange the orders for all meshes, we present a parallel algorithm based on geometry domain decomposition. A parallel code combining those two algorithms was designed. Using the code, we solved a two dimension particle transport equations on a cluster, performance results show the algorithms have well scalability.