Author: Kitagawa, A.
Paper Title Page
TUOMMH01 Improvement of Beam Intensities for Ion Beams with Charge-to-Mass Ratio of 1/3 with Two-Frequency Heating Technique 83
 
  • A. Kitagawa
    NIRS, Chiba-shi, Japan
  • T.F. Fujita, M. Muramatsu
    National Institute of Radiological Sciences, Chiba, Japan
  • K. Fukushima, N. Sasaki, K. Takahashi, W. Takasugi
    AEC, Chiba, Japan
  • Y. Kato
    Osaka University, Graduate School of Engineering, Osaka, Japan
 
  Facilities of heavy ion radiotherapy use carbon ions due to its better biological dose distributions. The necessary energy is over 400MeV/u. A typical accelerator system consisits of a synchrotron and an injector. ECR ion sources have been developed and utilized to produce C4+ ions. On the other hand, in order to study basic biological researches with a such facility, there are occasionally requirements to produce other ion species like Ar or Fe. Since the injector design is fixed for the acceleration of ions with a charge-to-mass ratio of about 1/3, the ion source must produce Ar13+ and Fe19+. As a method to improve highly-charged ion production, the technique to feed multiple microwaves with different frequencies is well-known. Our group studied the improvements when the two frequencies are close together each with a power of more than 1kW using the 18GHz NIRS-HEC ECR ion source installed in the Heavy Ion Medical Accelerator in Chiba (HIMAC. Fe and Ni are interesting for a risk study in space environment. We combined the MIVOC method and the two-frequency heating technique for the production of Fe and Ni. The recent test results will be reported.  
slides icon Slides TUOMMH01 [2.651 MB]