Development of apparatus for mean-lifetime measurement of cosmic-ray muons using plastic scintillation detectors and FLASH-ADC/FPGA-based readout electronics

Abstract

Introduction: This paper presents the development and results of an apparatus for measuring the mean lifetime of cosmic-ray muons. Methods: The apparatus uses three plastic scintillation detectors and a readout electronics system based on Flash Analog Digital Converter (Flash-ADC) and Embedded Field Programmable Gate Array (FPGA). The readout system has 8-bit resolution and a 125 Msample/sec sampling rate. The system's trigger and data collection are controlled through a computer interface based on LabVIEWTM. The readout electronics are calibrated with an accuracy of 8 nsec/TDC channel. Results: Over 6000 events were recorded during the measurements performed at ground level using aluminum as the muon stopping material, and the muon decay time spectrum was obtained and fit with a combination of two exponential components and a constant background. The mean lifetimes of negative and positive muons were determined. Conclusion: Our results indicate that the mean lifetimes of negative and positive muons in aluminum are 0.70 ± 0.24 µsec and 2.05 ± 0.16 µsec, respectively.