Spatial and Temporal Neutron Measurements on the Fusion Z-pinch Experiment (FuZE)

Nuclear fusion is a source of clean energy with many concepts in development. The Fusion Z-pinch Experiment (FuZE) is a sheared-flow stabilized Z-pinch device where the Portable and Adaptable Neutron Diagnostics for ARPA-E (PANDA) suite has been deployed since 2021 at the Zap Energy, Inc. facility. The FuZE capacitor banks are discharged to ionize neutral deuterium gas and induce pinch currents that cause fusion in deuterium plasmas. Neutrons with mean energies of 2.45 MeV are the only reaction product that can be detected outside of the device chamber. There are two types of neutron detectors in PANDA: fast plastic scintillators and lanthanum bromide (LaBr₃) activation detectors. 16 gain matched plastic scintillator detectors are fielded at FuZE to calculate the isotropy of emitted neutron energies and verify the thermonuclear origin of neutron emission. The time resolved axial profile of the neutron source is measured by placing the same detectors along the pinch region in the z axis of FuZE to determine where the plasma is hot and dense enough to produce neutrons. A cross-calibrated LaBr₃ activation detector measures the neutron yield for each discharge. These measurements are integrated with other diagnostics for a robust understanding of device performance.