Production of radioactive ^9C ion beam and its optimization

To explore the medical use of a radioactive ^9C-ion beam in tumor treatment, which is a double radiation source coming from the external beam itself and the delayed particles emitted internally, some physical experiments are performed at the Secondary Beam Line (SBL) of Heavy Ion Medical Accelerator, Chiba (HIMAC) in Japan before radiobiological research for exhibiting therapeutic value of the ^9C beam. Intention of the experiments is for producing a radioactive ^9C-ion beam with higher production rate and purity by means of optimizing the beam line parameters. Finally, a produced ^9C beam with the production rate of 9.07×10^-6 and purity of 82.88% at full momentum acceptance has been obtained under the optimal conditions of 40 nun-thick beryllium target and 10 mm-thick aluminum degrader. Both momentum distribution and contaminations for the produced ^9C beam under the optimal conditions are measured. In order to execute further biological experiments of the ^9C beam project, a uniform irradiation field is made with the wobbling magnets and its homogeneity is up to 93.8% inside central area of 20mm in diameter.