Li-Ion Batteries Used as Ubiquitous Neutron Sensors for Nuclear Forensics

With an increasingly complex worldwide nuclear environment, nuclear forensics provides a deterrent through proper attribution. Identifying the type of event is important in the attribution process, and the lithium battery has the potential to provide significant information for this purpose. The incident neutron spectral fluence is related to the type of nuclear event. The lithium battery is built using materials that can be used to assess the number of incident neutrons, as well as provide threshold detection dependant on the neutron energy. This study looks at correlating the production of various long-lived radioactive isotopes to the incident neutron spectrum. The analysis uses known nuclear cross sections and battery properties to calculate the number of long-lived radioactive elements that can be produced in the solid winding of the active battery elements, which include the cathode, separator, and anode. Some isotopes are only produced above a threshold energy, such as ⁵⁸Co , which requires 10.6 MeV neutrons. Other isotopes such as ³H are produced through various reaction channels, mostly ⁶Li(n,α)³H, which is an exothermic reaction, and is not associated with a threshold energy.