Solar Particle Event Detection With the LUMINA Optical Fiber Dosimeter Aboard the International Space Station

LUMINA, a fiber-based dosimeter, exploiting the radiation induced attenuation (RIA) phenomenon, has been operational inside the International Space Station (ISS) since August 2021. We discuss in this article its capability to detect the possible signatures of recent solar particle events (SPEs) through the related increase of the dose rate (DR) radiation level within the ISS. Our analysis over 699 days of operation shows that the two LUMINA channels, operating either in the visible or infrared (IR) domains, are able to detect the slight DR increase related to the solar flares (SFs), in particular, in the poles regions. The South Atlantic Anomaly (SAA) remains well detected by both LUMINA channels, but no significant increase of the DRs is noticable during the solar events in this region. These results were obtained at DRs close to the lower detection limit of our instrumentation, demonstrating the potential of fiber dosimeters, especially if less shielded, to detect the SFs and monitor the radiation environment.