A Monte Carlo Approach to Cutoffs and Charge State Measurements With SAMPEX/MAST Data

High energy ionic charge states in large, gradual solar energetic particle events have been reported using a geomagnetic rigidity filter technique. The current technique involves accumulating particle counts vs. invariant latitude and fitting geomagnetic cutoffs to these profiles in order to extract charge state measurements. However, the current technique does not yield cutoffs or charge states for situations involving low statistics, e.g. low particle abundances or smaller SEP events. To supplement the current technique, we have developed a Monte Carlo simulation to model the MAST data and to fit particle count vs. invariant latitude profiles. This simulation can also model the underlying probability distributions for low statistics situations, allowing us to attempt cutoff and charge states estimates for elements and SEP events for which we have not previously attempted measurements. We will report on the details of the simulation and the resulting SEP charge state estimates arising from new fits to the data.