The observation of Ground Level Enhancement GLE 77 by the neutron detectors of the Experimental Complex NEVOD

A Ground Level Enhancement event was observed by neutron detectors designed for the registration of extensive air showers at the Experimental Complex NEVOD. The potential for that was unlocked by a recent modernization of the experimental setup that included implementation of additional channels for measuring neutron flux variation. At 10:15 UT on November 11, 2025, a sudden and significant increase in the neutron flux was detected by two installations: PRISMA-36 and URAN arrays. For the first time, a GLE has been recorded using a set of neutron detectors oriented at the extensive air shower studies. We present the measured EC NEVOD data and the results of the preliminary analysis of the observed GLE.