Monte Carlo simulation of multistep reactions involving three particles in the exit channel

Abstract A Monte Carlo simulation procedure, adapted to microcomputers, is presented for the analysis of nuclear reaction data involving three particles in the final state. Essentially, the data are transformed from the laboratory to the center of mass system in which they can be interpreted. The simulation of competing reaction channels, such as sequential decay and target or projectile breakup, is shown to be useful even in the laboratory system. The procedure is applied to the 12 C + 12 C system which was recently investigated at energies near the Coulomb barrier in the 8 Be + 16 O → 2α + 16 O and 24 Mg ∗ → α′ + 20 Ne ∗ channels. The indistinguishable α″ group produced through the sequential decay α′ + α″ + 16 O gs is reproduced by simulation from the measured angular distributions W ( θ α ′ ). The art and pitfalls of pseudorandom number generation are also discussed.