Bringing non-destructive isotopic assay into the field with Dense Plasma Focus Nuclear Resonance Transmission Analysis*

Numerous global security nuclear threat reduction (NTR) missions require non-destructive, unambiguous, isotopic assay of shielded materials in the field, including safeguards, waste remediation, emergency response, and arms control. We will investigate using a miniaturized, short-pulse neutron source called a dense plasma focus (DPF) in a field-portable isotopic assay platform to detect shielded nuclear materials using a compact form of nuclear resonance transmission analysis (NRTA). The DPF's neutrons are moderated, passed through a sample, and measured as a neutron absorption energy spectrum "fingerprint" unique to each isotope. Nuclear materials can be identified and quantified using this measurement. We will use the radiation transport software MCNP to determine the limitations and number of neutrons required for the measurement. We will validate the result with experiments on the existing facility sized DPF NRTA setup to establish NRTA as a viable candidate for isotopic assay. The eventual system will require tritium for a 50x boost to neutron output, so we will explore a system with 1/50th the output needed with a deuterium-only setup for this project which could establish the DPF NRTA system as capable of meeting the requirements. Such a field deployable system could provide a major tool in tracking and accounting for nuclear materials and play a role in numerous missions.