The VERITAS VHE gamma-ray observatory recently completed a major upgrade of its camera and pattern triggering systems. Bias curve testing of the upgraded VERITAS Observatory under dark sky conditions indicates a 50% increase in photon detection effic
iency, and a 30% reduction in triggering threshold. Optimization of analysis of the Crab nebula observations performed in late 2012 and early 2013 is ongoing. A comparison of these results with pre-upgrade Crab observations can provide the most direct method for quantifying the impact of the upgrade on VERITAS sensitivity and energy threshold.
The VERITAS gamma ray observatory (Amado, AZ, veritas.sao.arizona.edu) uses the Imaging Atmospheric Cherenkov Technique (IACT) to study sources of Very High Energy (VHE: E > 100 GeV) gamma rays. Key science results from the first three years of obser
vation include the discovery of the first VHE emitting starburst galaxy, detection of new Active Galactic Nuclei (AGN), SuperNova Remnants (SNR), gamma ray binaries as well as strong limits on the emission of VHE gamma rays from dark matter annihilation in dwarf galaxies. In April 2010, VERITAS received funding to upgrade the photomultiplier tube cameras, pattern triggers, and networking systems in order to improve detector sensitivity, especially near detection threshold (E ~ 100 GeV). In this paper we describe the status of the VERITAS upgrade and the expected improvements in sensitivity when it is completed in summer 2012.
