Applications of plastic nuclear track detectors in heavy ion physics

Abstract

Abstract The experimental technique of computerized track measurements for plastic nuclear track detectors was used in different experiments investigating interactions of relativistic heavy ions. In this paper the method is described, results are presented and discussed. To measure cross sections stacks were exposed at the BEVALAC, at Brookhaven and at CERN to different beam nuclei having energies from 0.6 GeV/nucleon up to 200 GeV/nucleon. The cross sections for one nucleon removal are considerably enhanced at high energies due to electromagnetic dissociation. We investigated the effect of electromagnetic dissociation for different targets and projectiles. For heavy projectiles an exclusive analysis of nuclear fragmentation on an event by event basis was performed. Based on this the effect of multifragmentation can be studied. We exposed a stack of 100 CR39 foils to a 1 GeV/nucleon 197 Au beam at the BEVALAC. Events with up to 10 projectile fragments having a charge Z≥5 and coming out of the same interaction vertex were observed. To search for projectile fragments with fractional charge in relativistic heavy ion collisions, we exposed stacks of 50 CR39 foils behind a lead block of 15 cm depth to the ultrarelativistic heavy ion beams at Brookhaven and CERN. The charge resolution achieved in these experiments is o=0.027e.