Investigation Of The Fragmentation In The Reaction624A MeV²⁸Si In CH₂Target

Recently CR-39plastic nuclear track detector has been used forhigh energy nucleus-nucleus collision. High energy nucleus-nucleuscollision is very essential import parameters for propagationcalculations which describe effect of shielding against cosmicradiation heavy nuclei by walls of spaceship or planetary habitat.The basis of radiation biological and radioactive medicine also ishigh energy nucleus-nucleus collision. Tracking method formeasurement of projectile charge changing cross-section andcomparison of primary silicon projectiles and emitted fragments arevery important for high energy nucleus-nucleus collision.targets interleaved with CR-39plastic nuclear trackdetectors were irradiated with624A MeV ions. The exposureswere made at NIRS, Japan. This paper studies the eleventh target and the twelfth target were irradiated with624A MeV ions. Inthis experiment, the CR-39plastic nuclear track detectors areetched for very short time and scanned by an HSP-1000automatedscanning microscope to observe track etch pits. Etch pits of severalhundred nm in diameter can be observed. We applied this techniqueto charged particle imaging using CR-39plastic nuclear trackdetectors.By analyzing these data we can projectile charge changingcross-section and comparison of primary silicon projectiles andemitted fragments. The partial cross-sections of projectile fragmentproduction are consistent with other experimental results andshows an obvious odd-even effect. The emission angle of projectilefragment increases with the decrease of projectile fragmentcharge.