COSMIC RAY MEASUREMENTS EMPLOYING PLASTIC SCINTLLATION DETECTORS AND FLASH-ADC/FPGA-BASED READOUT SYSTEM

Abstract

It is known that secondary cosmic rays are high energetic particles which are products of shower particles, when primary cosmic rays from outer space hit the atmosphere molecules. Many studies of cosmic rays show that cosmic flux depends on the depth of atmosphere. At ground level, most secondary cosmic rays are muons, a type of charged particle, and have angular dependence. The purpose of this article was to develop the telescope with the use of two plastic scintillation detectors, to investigate the angular distribution of cosmic rays at ground level. Measurements were carried out for vertical, 45-degree oblique and horizontal directions with respect to earth surface, approximately from North to South. Electronic readout system was built from a Flash Analog Digital Converter (Flash-ADC) of 8 bits-250Ms/sec, and Embedded Field Programmable Gate Array (FPGA)-based trigger. A computer interface was written on LabVIEW^TM Platform for controlling system’s trigger and taking data. For each direction measurement, the energy spectrum in each scintillator detector was obtained. The interest of cosmic-ray events was analyzed for counting. Angular distribution was obtained quantitatively. The experiment has been done at University of Science-HCMC.