Stochastic Modeling and Simulation of Marginally Trapped Neutrons
Kevin J. Coakley
For a magnetic trapping experiment, I present an efficient method for simulating experimental beta −decay rates which accounts for loss of marginally trapped neutrons due to wall collisions and other possible loss mechanisms. Monte Carlo estimates of time-dependent survival probability functions for the wall loss mechanism are based on computer intensive tracking of marginally trapped neutrons with a symplectic integration method and a physical model for the loss probability of a neutron when it collides with a trap boundary. The simulation is highly efficient because after all relevant survival probabilities are determined, observed neutron decay events are quickly simulated by sampling from probability distribution functions associated with each survival probability function of interest. That is, computer intensive and time-consuming numerical simulation of a large number of additional UCN trajectories is not necessary.