Ryan Sacks with Dan Akerib and Mike Dragowsky

Monte Carlo Testing of a Gamma Veto Shielding System for LUX

Dark matter detection requires effective reduction and rejection of background events to accurately detect dark matter interactions. The LUX detector consists of a volume of liquid xenon with photo multiplier tubes inside of a sealed container shielded by a medium such as water or liquid scintillater. Upgrading the current LUX water shield would allow for effective detection of high energy gammas in the MeV range that have gone through small angle Compton scattering to produce an event in the main detector. Detection of the high energy gammas in the shield region will allow vetoing of the 10keV signals produced by the Compton scattering. Additional PMTs will be required to detect these events as the current set up does not have the required sensitivity to detect gammas in the shielding region. Neutron background from both the natural environment and the radioactivity from the PMTs must be rejected to ensure correct detection of dark matter events. Doping the outer water shield with gadolinium will allow for effective neutron detection. Feasibility and performance studies of the new designs will be done using MCNP Monte Carlo.