Verification of angular dependence for track sensitivity on several types of CR-39

We verified the angular dependence of track registration sensitivity for four types of CR-39 plastic nuclear track detectors using heavy ion beams. These detectors have been launched with several types of luminescence detectors on the Russian segment of the International Space Station (ISS) to intercompare passive radiation dosimeter components from several institutions. CR-39 detectors were irradiated by several kinds of heavy ions with several hundred MeV/n. All the etched tracks were analyzed using a high-speed microscope (HSP-1000) with ellipse fitting software (PitFit). Reduction of sensitivity was observed near the region of the critical angle. Corrections were made using an empirical method based on the known structure of the galactic cosmic ray spectrum.