• F. Noda
  Hitachi, Ltd., Energy and Environmental Systems laboratory, Hitachi-shi, Ibaraki-ken
• H. Akiyama
  Hitachi Ltd., Power & Industrial Systems, 1-1, Saiwai-cho, 3-chome
• F. Ebina, F. Fujitaka, H. Hae, H. Hiramoto, H. Nishiuchi, K. Saito, M. Umezawa
  Hitachi, Ltd., Energy and Environmental System Laboratory, Hitachi-shi

Slow cycle synchrotron system for cancer therapy is presented to realize the pencil beam scanning with carbon and proton. The designed synchrotron’s circumference is 60m and the maximum beam energies are 480MeV/u for carbon and 250MeV for proton. These energies correspond to the beam range of 35cm in water. In the treatment system with the present synchrotron, the discrete spot scanning scheme for lateral irradiation is employed using fast beam ON/OFF that is characteristic of the RF driven slow beam extraction from the synchrotron. Distal dose distribution is controlled with energy stacking technique, which is superimposing various bragg peaks which are controlled with the energy of the beam accelerated by the synchrotron. Furthermore, respiratory-gated operation with high throughput will be realized by the variable flat top length and timing for the beam extraction.