Gamma ray detection: building a didactic proposal

Abstract

A simple and economic scintillator kit in combination with a computer based oscilloscope was used to develop a learning experience, comprised of a set of activities to introduce students in an interactive way to the physics of gamma ray detection. The proposal for secondary school and university students is built by means of frequent on-the-fly formative assessment to collect difficulties of students and ways to overcome them. Internal decays of Lutetium–yttrium oxyorthosilicate (LYSO) crystals already present in the scintillator kit are used as sources of gamma rays, so no external sources were needed. In addition, the use of LYSO crystals offers a reason to discuss coincidence measurements, because of the inherent beta background present in the internal decay, which can be at least partially removed with coincidence measurements. The goal of the learning experience is to experience how gamma ray detection is actually done, discussing the physics involved, motivated by the current frontline research on the detection of gamma ray bursts.