Numerical Simulation On Interaction Between Intense Laser And Hydrogen-Cluster By Parallel Computing

The interaction of clusters with high intensity laser pulses has been studied extensively over the past few years. The unique properties of atomic and molecular clusters provide an efficient energetic transformation from laser pulse to ions and electrons. And some extraordinary observations have been explored, such as the production of highly charged ions energetic electrons and ions, strong x-ray emission. Numerical simulation has always been an efficient tool to study the interaction of high intensity laser with clusters, but limited by the calculation scale, common computer can not meet the requirement of large scale and multi-dimension clusters model, parallel computing and parallel algorithm is studied.In this paper, parallel numerical simulation of 2D hydrogen atom clusters ionized by intense laser pulse is studied along with the design of preliminary Time-of-Flight Mass Spectrometry experiment, which mainly includes:A two-dimensional hydrogen cluster model was performed. Newton equations and relativistic equations were used to solve motions of protons and electrons, respectively. The kinetic energy distributions of protons emitted from the Coulomb explosion were simulated. Compared with different cluster density and laser energy, the results showed: the kinetic energy of ions distributed with a Gaussian distribution and varied with the clusters density and laser energy. That is, the kinetic energy of ions from coulomb explosion grows with the growth of cluster density and the energy of laser pulse. And maximum kinetic energy saturate with light intensity. A phenomenological relaxation time parameter was introduced to approximate collisions among particles in a cluster which profoundly reduced computational workload while still attaining the essential physics. Compared with non-collision models, the results of this method were much more reasonable closer to experimental observations. The simulation was based on an parallel computing system with parallel algorithm, considered with MPI and OpenMP programming to optimize the algorithm, an ideal speedup is gained. The initial design of a TOF-MS experimental system was presented and expectations on future research work were also proposed.