Monte Carlo Simulations of the New Sampling Calorimeter for the Longitudinal Polarimeter at HERMES

The HERMES experiment at the DESY laboratory in Hamburg, Germany is measuring spin structure functions using polarized electrons and polarized targets. Before the Longitudinal Polarimeter, a Compton back-scattering laser polarimeter, was built in 1996, the beam polarization was known only with a large systematic uncertainty. After its commissioning, the fractional systematic uncertainty in the beam polarization was reduced to 1.6%. In order to improve upon this even further, the development of a new sampling calorimeter was begun in the fall of 1998. Recently, the calorimeter was tested for linearity up to 6 GeV in the DESY test beam and up to 20 GeV in the CERN test beam. The results showed the calorimeter to be linear to better than 1% over the entire energy range. To verify the excellent linearity displayed by the new sampling calorimeter, and to test other properties of this device, Monte Carlo simulations were run taking the beam conditions at both DESY and CERN into account. The results of the simulations will be presented alongside a comparison with the experimental results.