Construction and Characterization of Neutron Monitor at Daejeon, Korea

Abstract

The amount of cosmic radiation entering the Earth’s atmosphere is determined by, and is therefore an indicator of, the level of solar activity. As the solar activity approaches a maximum, the counts cosmic rays get increased. A NM64-type neutron monitor was installed at the Korea Research Institute of Standard Science in Korea in 2011 with a cutoff rigidity of 11.2 GV. The aim of this study is to analyze the barometric coefficient and the diurnal variation of Daejeon neutron monitor. The barometric coefficient and the diurnal variation is analyzed with data acquired during 2012. A reliable barometric coefficient is determined, -0.6597 0.0004 %/hPa, and the diurnal variation and the Forbush decrease events are observed. Even though the magnitude diurnal variation less than 1 % is hard to measure, the Daejeon neutron monitor is working well. Moreover, some Forbush decrease events are recorded simultaneously at Daejeon neutron monitor.