Author: Kumagai, K.
Paper Title Page
MO1PB01 Acceleration of Intense Heavy Ion Beams in RIBF Cascaded-Cyclotrons 1
  • N. Fukunishi, T. Dantsuka, M. Fujimaki, T. Fujinawa, H. Hasebe, Y. Higurashi, E. Ikezawa, H. Imao, T. Kageyama, O. Kamigaito, M. Kase, M. Kidera, M. Komiyama, H. Kuboki, K. Kumagai, T. Maie, M. Nagase, T. Nakagawa, M. Nakamura, J. Ohnishi, H. Okuno, K. Ozeki, N. Sakamoto, K. Suda, A. Uchiyama, T. Watanabe, Y. Watanabe, K. Yamada, H. Yamasawa
    RIKEN Nishina Center, Wako, Japan
  The RIBF cascaded-cyclotrons have obtained, as of December 2012, uranium ion beams with an intensity of as high as 15 pnA (1 kW of power). This was achieved owing to deployment of a 28 GHz ECRIS, a new injector linac, a gas stripper and a bending-power upgrade of RIKEN fixed-frequency Ring Cyclotron as well as improvement of transmission efficiencies through cyclotrons and stability, etc.   
slides icon Slides MO1PB01 [12.793 MB]  
TU3PB03 R&D of Helium Gas Stripper for Intense Uranium Beams 265
  • H. Imao, T. Dantsuka, M. Fujimaki, N. Fukunishi, H. Hasebe, O. Kamigaito, M. Kase, H. Kuboki, K. Kumagai, T. Maie, H. Okuno, T. Watanabe, Y. Watanabe, K. Yamada, Y. Yano
    RIKEN Nishina Center, Wako, Japan
  Intensity upgrade of uranium beams is one of the main concerns at the RIKEN Radioactive Isotope Beam Factory (RIBF). The lifetime problem of carbon-foil strippers due to the high energy loss of uranium beams around 10~MeV/u was a principal bottleneck for the intensity upgrade in the acceleration scheme at the RIBF. We have developed a re-circulating He-gas stripper as an alternative to carbon foils for the acceleration of high-power uranium beams. The new stripping system was actually operated in user runs with U35+ beams of more than 1 puA. Electron-stripped U64+ beams were stably delivered to subsequent accelerators without serious deterioration of the system for six weeks. The new He-gas stripper, which removed the primary bottleneck in the high-intensity uranium acceleration, greatly contributed the tenfold increase of the average output intensity of the uranium beams from the previous year.  
slides icon Slides TU3PB03 [11.983 MB]