Search for magnetic monopoles with nuclear track detectors

This paper describes an experimental search for GUT magnetic monopoles in the MACRO experiment using the nuclear track subdetector CR39. After discussing the working principle, the charge resolution and the calibration of the detector, the experimental procedure for searching for magnetic monopoles is described. Since no candidates were found, the upper flux limits obtained by the MACRO CR39 used as a "stand alone detector" for magnetic monopoles of different magnetic charges are presented.