B. Vulpescu et al., A COMPACT DETECTOR FOR THE MEASUREMENT OF THE COSMIC-RAY MUON CHARGE RATIO, Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 414(2-3), 1998, pp. 205-217
A compact sampling calorimeter is developed and used to measure the ra
tio between positive and negative muons in the cosmic-ray flux at mome
nta below 1 GeV/c. The delayed coincidence method is used, based on th
e reduced mean lifetime of negative muons due to nuclear capture in ma
tter. It is shown that aluminum is a good choice as a capture medium f
or negative muons and suitable for a simple detector set-up. The muon
charge ratio is found to be 1.30 +/- 0.05 for a mean momentum of 0.86
GeV/c and over a zenith angle acceptance with Theta(mean) = 26 degrees
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