Simulating the Germanium Crystal Segments of the GRETINA Detector Array

The Gamma-Ray Energy Tracking In-beam Nuclear Array, GRETINA, is a γ-ray spectrometer used to study the structure of atomic nuclei. GRETINA reconstructs the energy and location of each γ-ray interaction point from the nucleus as it de-excites using thirty-six high-purity electrically segmented germanium crystals. The research is centered around improving the accuracy and realism of the simulation that mimics the germanium semiconductor detectors in the gamma-ray spectrometer GRETINA. The objective is to implement a realistic segment shape in simulation and compare it with data for one detector by studying the efficiency of the segments. Python programming was used to create a function that yields segment number values from the crystal (x,y,z) coordinates, which allows us to remap the segment numbers in simulation. This allows us to look at the germanium crystal segments with more accuracy and better reproduce their efficiency for measuring γ-rays. Under those circumstances, we are able to gather data at a greater level of precision, which increases our level of confidence when using simulation to understand and interpret experimental data.