Energy calibration of germanium detectors for the MAJORANA DEMONSTRATOR

The Majorana Demonstrator was a search for neutrinoless double-beta decay (0 nu beta beta) in the Ge-76 isotope. It was staged at the 4850-foot level of the Sanford Underground Research Facility (SURF) in Lead, SD. The experiment consisted of 58 germanium detectors housed in a low background shield and was calibrated once per week by deploying a Th-228 line source for 1 to 2 hours. The energy scale calibration determination for the detector arraywas automated using custom analysis tools. We describe the offline procedure for calibration of the Demonstrator germanium detectors, including the simultaneous fitting of multiple spectral peaks, estimation of energy scale uncertainties, and the automation of the calibration procedure.