Measurement of the momentum dependence of atmospheric muon vertical intensity at ground level in Tunisia

Abstract

The momentum dependence of the vertical intensity of atmospheric muons has been measured for the first time in Tunisia (region of Monastir: 35.76 N, 10.81 E) at the ground level. The measurements were conducted using a variable thickness of a lead layer placed between two NaI(Tl) scintillators allowing a selection of muons with a minimal momentum ranging from 0.3 to 1.4 GeV/c. The number of detected muons and the corresponding vertical intensity were carefully evaluated exploiting the deposited energy spectrum in the scintillators and a Monte-Carlo simulation of the experimental setup. The comparison of our results to previous measurements is satisfactory and compatible with the geomagnetic latitude dependence of the muon flux. The present measurements could improve the modelization of cosmic ray intensity at sea level by filling the lack of experimental data in North Africa.