Calibration and Weather Studies of DEASA Detectors

DEASA (Dayalbagh Educational Air Shower Array) is a ground-based mini array to study Air shower phenomena at Dayalbagh Educational Institute [1], Agra in India located at 27.1767 \(^{\circ }\) N and 78.0081 \(^{\circ }\) E respectively and 170 m above sea level. It comprises 8 plastic scintillation detectors of dimensions (1 m  \(\times \)  1 m  \(\times \)  2 cm) and 2 prototype detectors of dimensions (23.5 cm  \(\times \)  24 cm  \(\times \)  2 cm). The total area covered by the array is 260 m \(^2\) . The pulse analysis of the prototype detectors has been done through the differential and integral pulse height spectra of MIPs (minimum ionizing particles) corresponding to amplitude peak values varying from 35.4 mV to 82.7 mV. The observational study of MIPs concerning the temperature of PMT is also interpreted. Generally, MIPs are muons, one of the elementary particles reaching towards the earth at sea level, they are weakly interacting particles and traverse through the material by ionizing the medium of the material of the detector[3]. When MIP traverses vertically through a plastic scintillation detector of thickness 2 cm, it deposits 3.15 MeV. These prototype detectors were used for calibration of the eight detectors every six months by coincidence method. Experimental observations involving count rate in hertz of MIPs using counter CAEN mod 1145 connected to the NIM unit have been graphically analyzed [2]. The graphs have been plotted between count rates at different temperatures (deg. C) and pressure (hPa) monthly for almost half a year. Statistics play a major role in the analysis of count rates in particle astrophysics. The experimental observations have been fitted with a Gaussian probability distribution function.