Scott Israel: MWD Algorithm Optimization in Mu2e's Stopping Target Monitor

The Mu2e experiment will search for coherent neutrino-less conversion of muons to electrons in muonic aluminum. The Mu2e Stopping Target Monitor employs two detectors optimized to detect photons from 100 keV up to a few MeV. One is a high-purity Germanium diode, and the other is a Lanthanum Bromide (LaBr) scintillator detector; they will measure X-rays and gamma rays ejected from the Mu2e stopping target to count the number of stopped muons. The waveform data from these detectors will be put through zero-suppression and moving-window-deconvolution (MWD) algorithms to obtain an energy histogram. In this report, we present the MWD parameters that optimize the energy resolution for LaBr using data from the ELBE test beam, in particular the ^{88}Y decay line at 1,836 keV, as a surrogate for the 1,809 keV line from muon capture on Al, which has a rate proportional to the number of stopped muons. A window width of 106.25ns and an averaging width of 46.875ns optimize the energy resolution at 10.8 +- 0.6 keV or sigma_E/E = 0.58%.