Total charge changing cross sections measurements for $^{12}$C ion interactions with Al using CR-39 nuclear track detector

Abstract

We are investigating the total charge changing cross-section of 12C by using the CR39 nuclear track detector. Target sandwiched with CR39 of 5 cm x 5 cm area was irradiated with $^{12}$C ion at 55 MeV/n and 135 MeV/n at the Wakasa wan Energy Research Center (WERC) and Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan, respectively. Exposed CR39s were etched in $^7$N NaOH solution at 70$^\circ$C to visualize the tracks produced by the primary ion beam and its fragmentations. The etching time was chosen between 15 and 25 hours according to exposed densities of $^{12}$C ions. The SEIKO FSP 1000 imaging microscope was used to get the image of the front and back surface etch pit simultaneously. Then by counting the projectile track before and after the target, the total charge changing cross-section has been measured. Since there are no previous experimental data to compare, PHITS and Glauber model calculated theoretical values were compared with the previous and this experimental result. From that, the measured data were found in good agreement with the previous and calculated value except for two points at energy 95.7 and 98.6 MeV/n. These two points need more analysis which will be done in the next phase. Measured data in this study will be the first experimental TCC data for $^{12}$C+Al interactions in the energy 100 MeV/n. These measured data will be useful to verify the models, optimize shielding in space radiation circumstances, and also to improve treatment planning on therapy, as well.