@misc{oai:repo.qst.go.jp:00063985,
 author = {Kitagawa, Atsushi and 北川 敦志},
 month = {Aug},
 note = {Since 1994, heavy-ion radiotherapy using carbon ions is successfully carried out with the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS).  Over 5000 cancer patients have already been treated with 140-400 MeV/u carbon beams.  These clinical results have clearly verified the advantages of carbon ion.  The ion source needs to realize a stable beam with the same conditions for daily operation. Maintenance is restricted to once per year. However, the deposition of carbon on the wall of the plasma chamber is normally unavoidable.  This causes an anti-wall-coating effect, i.e. a decreasing of the beam (typically 50 % after a few months of operation), especially for the higher charge-state ions due to the surface material of the wall.  The ion source has - even in this bad condition – still to produce a sufficiently intense and stable beam.  We summarize our experience during 16 years of operation and show the scope for further developments.  
HIMAC is dedicated to radiotherapy, but it has as a second essential task to operate as a facility for physicist users.  In that scope it accelerates many ion species for basic experiments.  In order to serve all HIMAC users at best, the extension of the range of ion species is an important subject in ion source development.  For example, in order to increase the ECRIS-beam intensity for heavier ions, microwave is applied at different frequencies by a traveling wave tube amplifier and by a klystron tube amplifier.  Double frequency heating improved the beam intensity after careful tuning of the additional microwave frequency. It seems that one of the main reason of improvement mainly is an increasing of plasma stability.  Results of these recent developments are reported.
\nHeavy ion radiotherapy awakens worldwide interest recently.  The clinical results obtained by the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS) in Japan have clearly demonstrated the advantages of carbon ion radiotherapy.  Presently, there are four facilities for heavy ion radiotherapy in operation, and several new facilities are under construction or being planned.  The most common requests for ion sources are a long lifetime and good stability and reproducibility.  Sufficient intensity has been achieved by electron cyclotron resonance ion sources at the present facilities., １．第１９回ＥＣＲイオン源に関する国際ワークショップ　　　２．欧州原子核研究機構（CERN）　３．ハンガリー原子核研究所（ATOMKI）},
 title = {1.Status of ion sources at HIMAC  2.Status on heavy ion radiotherapy facilities and related ion sources},
 year = {2010}
}