Dual-Particle Visualization with HoloLens 2 in an Inspection Scenario

Emerging technologies are continuously being introduced in the nuclear nonproliferation regime as equipment matures and new capabilities are developed, such as dual (neutron and gamma ray) imaging. Neutron and gamma ray imaging is a field that has experienced significant progress with respect to deployed systems. In early efforts, Compton cameras or neutron scatter cameras were limited by detectors or electronics but modern systems are more compact and have achieved significantly higher energy and spatial resolution. One factor that has remained the same however is the need to interpret the imaging information to locate or identify a source in the field. This work demonstrates the use of an application developed for the Microsoft HoloLens 2, a mixed reality headset, which combines the HoloLens-generated live spatial mesh of an environment with the imaging data measured with the University of Michigan’s handheld dual-particle imager (H2DPI). The H2DPI system is capable of both gamma-ray and fast-neutron imaging, enabling localization and identification of either type of radiation source. This capability is especially important for nonproliferation efforts in verification or management of nuclear material in facilities where one can encounter both neutrons and gamma rays, often at the same time. In this work, a mock inspection scenario is used to exhibit the current capabilities of the visualization application. Three storage containers are placed at a distance of 0.5 - 1 m from the H2DPI; one containing a Cf-252 source, another a Cs-137 source, and the third empty. Both neutron and gamma imaging modes are demonstrated and shown to correctly localize the corresponding sources to their respective barrels. Other features such as neutron and gamma ray spectrometry and user accessibility will also be demonstrated. This H2DPI and HoloLens 2 pipeline is intended to make source localization in the field more intuitive to users, regardless of background knowledge in nuclear engineering, by conveying imaging data in mixed-reality medium.