A flexible positron spectrometer for the undergraduate laboratory

Positron physics touches on a wide-ranging variety of fields from materials science to medical imaging to high energy physics. In this paper, we present the development of a flexible positron annihilation spectrometer appropriate for the undergraduate laboratory. Four NaI gamma-ray (gamma-ray) detectors are connected to an oscilloscope-based data acquisition system. Coupled with the software we developed, these detectors allow students to explore a variety of positron and gamma-ray phenomena. These include gamma-ray energy spectroscopy, Compton scattering, PET scanning fundamentals, speed of light measurements with gamma-rays, historically important polarimetry of annihilation radiation, 3-gamma annihilation radiation observations, and positron lifetime spectroscopy of materials. We present the developed apparatus and examples of experiments it can perform here. A website, https://wp. stolaf. edu/physics/positron-laboratory-for-undergraduates/, has also been developed to present supplementary materials including apparatus drawings, laboratory write-ups, developed software, and an instructors' manual. (C) 2018 American Association of Physics Teachers.