The upgraded low-background germanium counting facility Gator for high-sensitivity γ-ray spectrometry

We describe the upgrade and performance of high-purity germanium counting facility Gator, which is dedicated to low-background $\gamma$-ray spectrometry. Gator operated at Gran Sasso Underground Laboratory in Italy, an average depth 3600 meter water equivalent, employed for material screening selection ultra-low background, rare-event search experiments astroparticle physics. The detector equipped with a passive shield made layers copper, lead polyethylene, sample cavity purged gaseous nitrogen maintained positive pressure radon suppression. After upgrading its enclosure, background rate (82.0$\pm$0.7) counts/(kg$\cdot$day) energy region 100 keV 2700 keV, 20% reduction compared previously reported rate. show stability various operation parameters as function time. also summarize analysis procedure, demonstrate Gator's sensitivity by examining one sample, candidate photosensor DARWIN experiment.