. in s - de t ] 5 D ec 2 00 8 Nuclear Track Detectors . Searches for Exotic Particles

We used Nuclear Track Detectors (NTD) CR39 and Makrofol for many purposes: i) Exposures at the SPS and at lower energy accelerator heavy ion beams for calibration purposes and for fragmentation studies. ii) Searches for GUT and Intermediate Mass Magnetic Monopoles (IMM), nuclearites, Q-balls and strangelets in the cosmic radiation. The MACRO experiment in the Gran Sasso underground lab, with ∼1000 m2 of CR39 detectors (plus scintillators and streamer tubes), established an upper limit for superheavy GUT poles at the level of 1.4×10−16 cm−2 s−1 sr−1 for 4×10−5<β<1. The SLIM experiment at the high altitude Chacaltaya lab (5230 m a.s.l.), using 427 m2 of CR39 detectors exposed for 4.22 y, gave an upper limit for IMMs of ∼1.3×10−15 cm−2 s−1 sr−1. The experiments yielded interesting upper limits also on the fluxes of the other mentioned exotic particles. iii) Environmental studies, radiation monitoring, neutron dosimetry.