Neutron Multiplicity Measurements for the AFCI Program Final Quarterly Progress Report January-March 2006

This project was developed to test a Russian-built Neutron Multiplicity Detector System (NMDS) for measuring neutrons generated in a central target by a variety of accelerators. To assist in experiment design and evaluation, we use the most advanced high-energy radiation transport code, MCNPX, to model experiments. Experimental results are compared to computational predictions and discrepancies are investigated. Initial plans were to conduct experiments using a 70-MeV proton cyclotron at the Crocker Nuclear Laboratory at the University of California at Davis and/or a 20 to 40 MeV electron linac (linear accelerator) at the Idaho Accelerator Center (IAC) at Idaho State University (ISU). Finally, we planned to use the 800-MeV proton linac at the Los Alamos Neutron Science Center at Los Alamos National Laboratory and to compare the performance of the NMDS . The project was terminated without completing accelerator testing as the system could not perform at the counting rates required for existing high-energy accelerators operating at any reasonable current. The NMDS will now be used in a new project to assay separations processing streams for Materials Protection, Accounting, and Control (TRP Task 30)