First results from the ENTOTO neutron monitor: Quantifying the waiting time distribution

TL;DR

This paper presents initial findings from the ENTOTO neutron monitor, a new instrument capable of measuring neutron waiting times and a novel correlation ratio, aiming to improve understanding of cosmic ray behavior.

Contribution

Introduction of a mini-neutron monitor at ENTOTO capable of detailed neutron pulse analysis and proposing the correlation ratio as a potential proxy for atmospheric particle spectral index.

Findings

Successfully measured neutron waiting time distribution.

Defined and proposed the correlation ratio as a new analytical tool.

Weak pressure dependence observed for the correlation ratio.

Abstract

We discuss a newly established neutron monitor station installed at the ENTOTO Observatory Research Center outside of Addis Ababa, Ethiopia. This is a version of a mini-neutron monitor, recently upgraded to detect individual neutrons and able to calculate the waiting time distribution between neutron pulses down to $\sim 1 $ $\mu$s. From the waiting time distribution we define and calculate a new quantity, the correlation ratio, as the ratio of correlated to uncorrelated neutrons measured inside the monitor. We propose that this quantity can, in future, be used as a proxy for spectral index of atmospheric particles incident on the monitor and show that this quantity has a weak pressure dependence. We believe that future measurements from the ENTOTO mini-neutron monitor will contribute towards the understanding of cosmic ray acceleration and transport in the heliosphere.