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High-energy carbon-ion radiotherapy is being carried out at Heavy Ion Medical Accelerator in Chiba (HIMAC). Over 12000 cancer patients have been treated with carbon beams having energies of between 56-430 MeV/u since 1994. There are two injectors in the HIMAC for medical and experimental use. First injector consists of two ECR ion sources and one PIG ion source, the RFQ linac and the DTL. Usually, this injector suppling the carbon ion for cancer therapy and various ion such as H, He, Fe, Xe are accelerated for biological and physical experiment. The 10 GHz NIRS-ECR ion source produce the carbon ion for cancer therapy. The 18 GHz NIRS-HEC ion source produce He to Xe ions for experimental use. Second injector consists of the compact ECR ion source with all permanent magnet, the RFQ linac and the APF IH-DTL. This injector supplies the carbon ion for experimental use. Additionally, we tried production of the Indium and the Tin ions by using the In(C5H5) and the Sn(i-C3H7)4 at the NIRS-HEC. Beam current of the 115In²⁰⁺ and 120Sn¹⁸⁺ were 90 and 15μA, respectively. Present status of ECR ion sources and some development will be described., Proceedings of the 24th International Workshop on ECR Ion Sources, ECRIS2020, East Lansing, MI, USA

High-energy carbon-ion radiotherapy is being carried out at Heavy Ion Medical Accelerator in Chiba (HIMAC). Over 11000 cancer patients have been treated with carbon beams having energies of between 56-430 MeV/u since 1994. At present, multi ion irradiation method by various ion species is being studied for optimization of LET and dose distribution. An ion source has to produce the helium, carbon, oxygen and neon at pulse by pulse for this method. Requirement currents for He²+, C²+, O³+ and Ne⁴+ are 500, 150, 230 and 300 eµA, respectively. We obtained beam current of 482, 151, and 270 eµA for He²⁺, C²⁺ and O³⁺ with mixed helium and CO² gases under the extraction voltage of 27 kV. Beam current of 27 and 15 eµA for C⁵+ and O⁷+ ions were also obtained in this time. He²⁺ beam include full striped ion such as C⁶+, N⁷+ and O⁸+. We have to increase the purity of He²+ beam. The gas feed system was modified for making pulsed gas by using a solenoid valve for switching different gas. Some experimental results of various ion productions will be described., Proceedings of the 23th Int. Workshop on ECR Ion Sources, ECRIS2018, Catania, Italy