Studies of Neutron-Rich Unbound Nuclei Using the MoNA Detector

Marquette University, Milwaukee WI

Investigators

Abstract

Determination of the energies, decay modes and orbital structure for the ground states of neutron-unstable nuclei will provide important tests of current nuclear models. The Modular Neutron Array (MoNA) detector and the Sweeper, a compact superconducting magnet with a wide acceptance angle, have been installed at the National Superconducting Cyclotron Laboratory (NSCL). MoNA was built by a collaboration consisting mostly of undergraduate institutions. By using MoNA and the Sweeper in combination, it is possible to measure the complete kinematics of both charged fragments and neutrons. This capability in conjunction with the more intense and energetic beams of the coupled cyclotrons allows the study of a series of particle-unstable nuclei near the neutron drip line that were previously inaccessible to experimenters. Undergraduate physics majors in physics departments without graduate programs, including Marquette University, will conduct these experiments during the summer and during the academic year from their home institutions. This allows undergraduates to play a significant role in the work of a major user facility, and the model can be extended to other large user facilities. Involving undergraduates has the dual benefit of raising the profile of nuclear physics at the kinds of institutions that produce more than half of all physics majors and of providing the user facility with a pool of talented workers.