MRI: Acquisition of an All Digital Multiparameter Gamma Spectroscopy System for Research and Research Training in Nuclear Physics

Wittenberg University, Springfield OH

Investigators

Abstract

The weak interaction, one of the four fundamental forces of nature, is responsible for the type of radioactive decay called beta decay. Precise measurements of beta decay can probe the limits of our understanding of the weak interaction, complementing particle collider experiments in the search for new physics while being much less costly. The recent development of facilities, such as at the National Superconducting Cyclotron Laboratory, that can produce a variety of beams of radioactive isotopes has created new opportunities for improved beta decay measurements. To fully exploit the potential of these new isotopes requires a good understanding of the response of various types of particle detectors. Understanding the response of particle detectors is also important for many applications in homeland security, nuclear safeguards, and medicine. The instrument to be acquired through this grant will enable the measurement of the response of a variety of particle detectors to a new level of precision over a wide energy range. Precise measurements of the shapes of spectra in nuclear beta decay are sensitive to physics beyond the Standard Model of particle interactions. The recent development of powerful radioactive beam facilities has created a new opportunity for improved measurements of nuclear beta spectrum shapes through implantation of the nuclei in detectors that fully contain the emitted particles. In the ideal case, this provides measurements free of many of the systematic effects more conventional beta spectroscopy is subject to. Fully exploiting the potential of the new detector method, however, requires precise knowledge of implantation detector response. This detector response characterization is the primary research to be enabled by the proposed acquisition of an all-digital multi-parameter gamma spectroscopy system. The basis of the characterizations is the Wide Angle Compton Coincidence technique. This technique uses Compton scattering with standard gamma sources of modest strength to characterize the energy dependent electron response of essentially any detector material relative to, for example, a High Purity Germanium detector. The system acquired under this proposal will enable the measurement of the nonlinearity of a wide variety of detectors to a new level of precision and over a wider energy range than presently exists.