Measurement of 12C Fragmentation Cross Sections on C, O, and H in the Energy Range of Interest for Particle Therapy Applications

In a carbon ion treatment the nuclear fragmentationof both target and beam projectiles impacts on the dose releasedon the tumor and on the surrounding healthy tissues. Carbon ionfragmentation occurring inside the patient body has to be stud-ied in order to take into account this contribution. These dataare also important for the development of the range monitoringtechniques with charged particles. The production of chargedfragments generated by carbon ion beams of 115-353 MeV/ukinetic energy impinging on carbon, oxygen, and hydrogen tar-gets has been measured at the CNAO particle therapy center(Pavia, Italy). The use of thin targets of graphite (C), PMMA(C2O5H8) and polyvinyl-toluene [plastic scintillator (PS), CbHa]allowed to measure fragments production cross sections, exploit-ing a time-of-flight (ToF) technique. PS detectors have been usedto perform the ToF measurements, while LYSO crystals havebeen used for the deposited energy measurement and to performparticle identification. Cross sections have been measured at 90◦and 60◦with respect to the beam direction. The measured pro-ton, deuteron, and triton differential production cross sectionson C, O, and H, obtained exploiting the target subtraction strat-egy, are presented here as a function of the fragment kineticenergy.