Solar Photovoltaic Devices as Radiation Sensors for Post-detonation Nuclear Forensics

In this study, we evaluated the feasibility of applying solar photovoltaic (PV) panels as sensors of nuclear and electromagnetic radiation that includes neutrons, x-rays and gamma-rays, and optical radiation emanating from a nuclear explosion. We investigated the steady-state and transient response of both a commercial silicon (Si) and a perovskite solar cell to different radiation types. Solar cell current-voltage characteristics and short-circuit current (Isc) response under steady-state x-ray illumination were measured. The fast transient radiation pulse from a nuclear detonation was mimicked by using a fast switching, nanosecond pulsed laser source and the transient response of the solar cells was captured on an oscilloscope. Subsequently, the transient response of Si solar cells to pulsed x-rays generated by a mechanical x-ray chopper was measured. A 2 MeV neutron beam chopper was built at the fast neutron beam facility of a research reactor to produce time-modulated neutrons and evaluate the solar cell transient response to a neutron pulse. Our steady-state measurements demonstrated good response of solar cells to x-rays and neutrons. The pulsed radiation measurements indicated that the solar cells are able to detect a fast transient radiation and produce a proportional measurable output signature.