Neutron yields inferred from neutron time-of-flight (nToF) traces for the Magnetized Liner Inertial Fusion (MagLIF) experiments.

Accurately measuring neutron yields is crucial for understanding the performance and scaling of the MagLIF experiments performed at the Z Pulsed Power Facility. This work presents a technique for measuring neutron yields from neutron time-of-flight (nToF) detectors, which are fielded at radial and axial locations around the neutron source. Each detector consists of a fast plastic scintillator coupled to one or more photomultiplier tubes (PMTs). Outputs from PMTs are digitized on multiple channels with GHz-bandwidth oscilloscopes. The technique for measuring neutron yields involves calculating the charge deposited from neutrons incident on the detector and measuring detector-specific calibration factors to convert the charge into incident neutrons. The charge from incident neutrons is calculated by subtracting a background and integrating the neutron component on the digitized nToF trace. Detector-specific calibration factors are measured at Sandia National Laboratories Ion Beam Laboratory, using a setup designed to generate neutrons through beam-target fusion reactions. Yields measured from nToF traces can be applied to calculate the degree of spatial isotropy for neutron emission and will be compared with neutron activation yields. Prepared by LLNL under Contract DE-AC52-07NA27344. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.