Authors: Chloe Heifner (University of Delaware & University of Wisconsin-River Falls), John Clem (University of Delaware), Paul Evenson (UD), Pierre-Simon Mangeard (University of Delaware), Scott Martin (University of Delaware), Ben Maruca (University of Delaware) and Surujhdeo Seunarine (University of Wisconsin-River Falls)

Neutron monitors are ground-based detectors that indirectly observe cosmic ray flux by detecting secondary particles that reach the Earth’s surface. The electronic components within the neutron monitor can record the energy deposited and the time that has elapsed between detections in each proportional tube, the central component of the monitor. This timing information is used to examine correlations in the data as a function of cutoff rigidity and the primary spectrum. Neutron monitors can detect correlated events (observed counts originating from the same primary particle) or uncorrelated events (observed counts originating from different primary particles). Furthermore, the timing information has provided a unique opportunity to make observations of multiple detection events occurring within a 1ms time window, which we call “catch” events. Previous results suggest that these events are likely caused by air showers impacting the neutron monitor. However, the results from this earlier work are somewhat inconclusive. The current work focuses on making a definitive measurement of the response of a neutron monitor to cosmic ray air showers by placing five scintillator detectors on top of the Newark Neutron Monitor. A five-fold coincidence of the five scintillators was used to restrict the analysis to events where air shower secondaries passed through all of the scintillators simultaneously, reducing the chance of uncorrelated secondaries originating from different air showers. In the case an air shower satisfies the five-fold coincidence requirement, the neutron monitor response to the event was analyzed to search for “catch” events that may have been associated with the corresponding cosmic ray air shower.