Publication Date


Document Type


First Advisor

Green, James (Professor of physics)

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Physics


Cosmic ray muons--Measurement


A measurement of the cosmic ray muon charge ratio distribution at sea level (μ⁺/μ⁻) has been made over the momentum range of 5 - 250GeV/c by collecting raw data from a muon spectrometer with iron toroid magnets and by conducting extensive computer software analysis on this data. The charge ratio results over the momentum range of 40 - 250 GeV/c agree with other experimental results, and over the range of 40 - 130GeV/c they also agree with the theoretical charge ratio values from two models considered. The results over the momentum range of 5 - 40GeV/c were significantly greater than the other experimental results and the theoretical values. The high values at the low momenta are most likely due to a bias caused by an improperly programmed circuit board designed to reject muons with momenta less than 5GeV/c. To get the best results from the software analysis, various calibration constants had to be used and corrections had to be made to the positions of muon tracks through the spectrometer to account for relative rotations of different parts of the detector. Obtaining the calibration constants involved computer processing of special data sets and iterative processing of small, normal data sets.


Includes bibliographical references (pages [80]-81).


viii, 81 pages




Northern Illinois University

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