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A RIKEN 18 GHz electron cyclotron resonance ion source (18 GHz ECRIS) is used as an external ion source at the Radioactive Ion Beam Factory (RIBF) accelerator complex to produce an intense beam of medium-mass heavy ions (e.g., Ca and Ar). In most components that comprise the RIBF, the control systems (CSs) are integrated by the Experimental Physics and Industrial Control System (EPICS). On the other hand, a non-EPICS-based system has hardwired controllers, and it is used in the 18 GHz ECRIS CS as an independent system. In terms of efficient and effective operation, the 18 GHz ECRIS CS as well as the RIBF CS should be renewed using EPICS. Therefore, we constructed an 18 GHz ECRIS CS by using programmable logic controllers with embedded EPICS technology. In the renewed system, an operational log system was developed as a new feature, for supporting of the18 GHz ECRIS operation. [ABSTRACT FROM AUTHOR]

We measured the main plasma parameters (density of electron, temperature of electrons, and ion confinement time) as a function of Bmin and Binj with laser ablation technique. We observed that the Bmin mainly affects the temperature and density of electrons and all of the three parameters increase with increasing the Binj. We also observed that the gas pressure of the plasma chamber at the rf injection side became minimum at the optimum value for Bmin at fixed gas flow. This result indicates that the ionization efficiency becomes maximum at optimum value for Bmin. From these results, it is concluded that the plasma production is strongly dependent on the Bmin (plasma generator). We also observed that the Binj affects the ion confinement time, temperature, and density of electrons. All of the three parameters increase with increasing Binj. [ABSTRACT FROM AUTHOR]

In order to produce a high-intensity and stable 48Ca beam from the RIKEN 18-GHz electron cyclotron resonance ion source, we have begun testing the production of a calcium beam using a micro-oven. To minimize the consumption rate of the material (48Ca), we introduced the "hot liner" method and investigated the effect of the liner on the material consumption rate. The micro-oven was first used to produce the 48Ca beam for experiments in the RIKEN radioisotope beam factory, and a stable beam could be supplied for a long time with low consumption rate. [ABSTRACT FROM AUTHOR]

Beam intensities of highly charged Ar ions (Ar11+,12+) were measured as a function of plasma electrode position. We observed that the beam intensity of Ar11+,12+ increased when putting the electrode far from the electron-cyclotron-resonance zone. On the other hand, lower charged heavy ions (Ar8+,7+) dramatically decreased. We observed that the intense beam extraction strongly affects the plasma condition. It may be due to the ion pumping effect. [ABSTRACT FROM AUTHOR]

In order to investigate the ion-optical parameters of the RIKEN 18 GHz electron cyclotron resonance ion source injection line into the RIKEN RFQ linac, we measured the beam emittance for a wide mass range of the ions. First results indicate a strong extraction current dependence of the normalized emittance. When using the insertion method to produce metallic ions from solid rod with high melting point, we observed that the beam emittance of metallic ions was very large compared to the beam emittance of ions from gaseous element. It may be due to the plasma instability caused by inserting the rod into the plasma deeply. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

As required by the research group of super heavy elements, highly intense beams of 58Fe and 64Ni ions were produced from RIKEN 18 GHz electron cyclotron resonance ion source [Nakagawa et al., Nucl. Instrum. Methods Phys. Res. A 396, 9 (1997)] using the MIVOC method. Maximum intensities of the supplied ion beams were 20 eμA at the extraction voltage of 15.9 kV for 58Fe13+ and 90 eμA at the extraction voltage of 17.5 kV for 64Ni13+. Consumption rate was about 1.2 mg/h for 58Fe and 64Ni, respectively. For the Radio Isotope Beam Factory [Yano, Proceedings of the 15th International Conference on Cyclotron and Their Application [(IOP, Bristol, 1999)] and various requests from users groups, we constructed a double beam injector system for the two ion sources as an external ion source of the Riken Heavy Ion Linear Accelerator [Odera et al., Nucl. Instrum. Methods Phys. Res. A 221, 187 (1984)]. Two ion sources; RAMSES [Arai et al., Nucl. Instrum. Methods Phys. Res. A 491, 9 (2002)] and 18 GHz ECRIS, will be placed at these at the beginning of next year. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]