Tracking method for the measurement of projectile charge changing cross-section using CR-39 detector with a high speed imaging microscope

Abstract

A new method to trace heavy ion trajectories in a stack consisting of interleaved CR-39 plastic nuclear track detectors and target material layers was developed and tested for use in the measurement of projectile charge changing cross-sections of heavy ion fragmentation reactions. A high speed imaging microscope with sophisticated track analysis software was utilized to extract the charge information from multiple ion tracks belonging to a single fragmentation event. The systematic error of trajectory tracing was verified for the measurement system. In order to verify the validity of system, the projectile total charge changing cross-sections for Fe ions on carbon target was estimated and compared with previous experiments at initial beam energy of 1 GeV/n. The result is in good agreement with results obtained by other investigators. This method allows precise and fast measurement of the projectile charge changing cross-section with higher statistics on a level compatible to that of silicon spectrometer measurements.