CALIBRATION WITH RELATIVISTIC AND LOW-VELOCITY IONS OF A CR-39 NUCLEAR TRACK DETECTOR

We present experimental results on the calibration of the CR39 nuclear track detector, manufactured by the Intercast Europe Co., of Parma (I taly). The calibration was performed with several ions of different ki netic energies: from 50 keV protons to 11.3 A GeV gold ions; beta=v/c ranges from about 4 . 10(-3) to about 1. We find that a single curve o f the reduced etch rate p versus Restricted Energy Loss is able to des cribe all data. Furthermore the data are consistent with about 100% co ntribution of the nuclear energy loss to the CR39 response. This type of CR39 is used in the MACRO experiment at the Gran Sasso Laboratory.