1. A logging tool comprising: a stabilization source configured to emit gamma rays; a gamma ray detector configured to collect gamma rays from the stabilization source and a formation; and an analysis module including instructions on a non-transitory computer-readable medium, the instructions, when loaded and executed by a processor, configure the analysis module to: determine a photopeak of the stabilization source in an energy spectrum of gamma rays collected by the gamma ray detector; and perform resolution calculations using the photopeak of the stabilization source to determine a resolution of the gamma ray detector.