Changes in Low Energy Neutron Counts Rate near Ground Level Associated to Steady Rain

Abstract

Measurements of neutron count rate (0.025 to 10 ) at ground level were performed with a single free (He-3) tube detectorthat is located near ground level in Aeronautical Institute of Technology (ITA) São José dos Campos, SP, Brazil. The data were collected uninterruptedly since February 28, 2016 to March 11, 2016. Based on the analysis of data obtained in this period, was possible to observe the occurrence of events, backscattering for example,with significant increases in the neutron count rate during about 3 days of steady rain for all nearby regions. These events seem to be correlated with changes in local weather conditions such as cloud coverage or rain-precipitation of weak intensity. It was reported that the non-observation of a single event seems to be an indicative of the production of a burst of neutrons by a lightning discharge near the detector. Some explanations about the increasing of low energy neutrons are suggested in this article.