Concurrent and vectorized Monte Carlo simulation of the evolution of an assembly of particles increasing in number

Parallel Monte Carlo techniques for simulating the evolution of an assembly of charged particles interacting with a background gas medium under the influence of the electrical field are presented. This simulation problem has inherent parallelism in nature. All the particles can be traced independently in a short time interval. We have overcome three major difficulties: 1) the number of particles to be simulated is increasing over time due to the ionization process; 2) the conditional branching statements do not inhibit multiprocessing through proper manual program tuning; 3) concurrency and vectorization are fully utilized through the new parallelized Monte Carlo method. The shared—memory vector multiprocessor Alliant FX/80 has been used for performance measurements. Significant speedup has been achieved.