Fits of Geant4 simulations of GRETINA to source and in-beam spectra

In preparation for an experiment with GRETINA at the NSCL planned for spring of 2013, we traveled to the National Superconducting Cyclotron Laboratory to collect source spectra and in-beam data from GRETINA. We have compared Geant4 simulations with measured photopeak efficiencies and fits to measured spectra with the aim of improving the accuracy of the simulation code. Fits of simulations to source and in-beam spectra will be presented.