Submission Date


Document Type

Paper- Restricted to Campus Access


Physics & Astronomy

Faculty Mentor

Lewis Riley


Presented during the 18th Annual Summer Fellows Symposium, July 22, 2016 at Ursinus College.

Project Description

We tested and improved upon computer simulations of the GRETINA gamma ray tracking array that is used to study the structure and properties of atomic nuclei at several national laboratories. As part of this work, it was necessary to assess photopeak efficiencies, the probability that the full energy of a gamma ray is collected, in order to fully understand and utilize experimental data. We developed a method to determine the thickness of the ‘dead layer’ of the back surface of the crystal by comparing measured photopeak efficiencies involving the back layer of segments with simulations. Because GRETINA contains two types of crystals with slightly different geometries, we also studied the relative photopeak efficiencies of the two crystal types. The purpose of our work was to validate the models used in the simulation code against radioactive source measurements. The finished product of this research will be reported at the fall meeting of the Division of Nuclear Physics of the American Physical Society in Vancouver, BC, this October.