Latitude Survey of Neutrons and Muons to Determine Cosmic Ray Neutron Sensing YieldFunction

Cosmic Ray Neutron Sensing (CRNS) is a ground based technique that utilises epithermal neutron measurements as a proxy for environmental hydrogen content. Similarly, to other ground based cosmic ray detectors (e.g. neutron monitors), CRNS detectors observe the solar cycle and space weather events. Typically, these effects must be corrected, but CRNS detectors have also been specifically used to observe space weather. The specific sensitivity of CRNS detectors to the primary spectrum and the relationship to other cosmic ray measurements is not fully understood. During the maximum of solar cycle 25 a latitude survey utilising a mini neutron monitor (MNM), two CRNS detectors of different design and a muon telescope was undertaken onboard the German Research Vessel Polarstern. The observations are used to derive differential response functions and yield functions for two neutron detectors. While the differential response, between neutron detectors is similar, it strongly deviates between muon and neutron detectors. The yield functions of CRNS and MNM are in good agreement with each other, indicating that CRNS detectors and MNM observe a comparable range of the primary cosmic ray spectrum.