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Title: Control system renewal for efficient operation in RIKEN 18 GHz electron cyclotron resonance ion source

Abstract

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 the 18 GHz ECRIS operation.

Authors:
; ; ; ; ;  [1]
  1. RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)
Publication Date:
OSTI Identifier:
22482881
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 87; Journal Issue: 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ACCELERATORS; COMPLEXES; CONTROL SYSTEMS; ECR ION SOURCES; GHZ RANGE; HEAVY IONS; JAPANESE ORGANIZATIONS; MASS; OPERATION; RADIOACTIVE ION BEAMS

Citation Formats

Uchiyama, A., E-mail: a-uchi@riken.jp, Ozeki, K., Higurashi, Y., Kidera, M., Komiyama, M., and Nakagawa, T. Control system renewal for efficient operation in RIKEN 18 GHz electron cyclotron resonance ion source. United States: N. p., 2016. Web. doi:10.1063/1.4934614.
Uchiyama, A., E-mail: a-uchi@riken.jp, Ozeki, K., Higurashi, Y., Kidera, M., Komiyama, M., & Nakagawa, T. Control system renewal for efficient operation in RIKEN 18 GHz electron cyclotron resonance ion source. United States. doi:10.1063/1.4934614.
Uchiyama, A., E-mail: a-uchi@riken.jp, Ozeki, K., Higurashi, Y., Kidera, M., Komiyama, M., and Nakagawa, T. 2016. "Control system renewal for efficient operation in RIKEN 18 GHz electron cyclotron resonance ion source". United States. doi:10.1063/1.4934614.
@article{osti_22482881,
title = {Control system renewal for efficient operation in RIKEN 18 GHz electron cyclotron resonance ion source},
author = {Uchiyama, A., E-mail: a-uchi@riken.jp and Ozeki, K. and Higurashi, Y. and Kidera, M. and Komiyama, M. and Nakagawa, T.},
abstractNote = {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 the 18 GHz ECRIS operation.},
doi = {10.1063/1.4934614},
journal = {Review of Scientific Instruments},
number = 2,
volume = 87,
place = {United States},
year = 2016,
month = 2
}
  • We have developed a new analytical system that consists of an electron cyclotron resonance ion source (RIKEN 18 GHz ECRIS) and a RIKEN heavy ion linear accelerator (RILAC). This system is called trace element analysis using electron cyclotron resonance ion source and RILAC (ECRIS-RILAC-TEA). ECRIS-RILAC-TEA has several advantages as described in the work of Kidera et al. [AIP Conf. Proc. 749, 85 (2005)]. However, many experimental results during the last several years revealed a few problems: (1) large background contamination in the ECRIS, particularly at the surface of the plasma chamber wall, (2) high counting of the ionization chamber andmore » the data taking system that is monitored by the direct beam from the accelerator, and (3) difficulty in the selection of the pilot sample and pilot beam production from the ECRIS for the purpose of normalization. In order to overcome these problems, we conducted several test experiments over the past year. In this article, we report the experimental results in detail and future plans for improving this system.« less
  • We measured the main plasma parameters (density of electron, temperature of electrons, and ion confinement time) as a function of B{sub min} and B{sub inj} with laser ablation technique. We observed that the B{sub min} mainly affects the temperature and density of electrons and all of the three parameters increase with increasing the B{sub inj}. We also observed that the gas pressure of the plasma chamber at the rf injection side became minimum at the optimum value for B{sub min} at fixed gas flow. This result indicates that the ionization efficiency becomes maximum at optimum value for B{sub min}. Frommore » these results, it is concluded that the plasma production is strongly dependent on the B{sub min} (plasma generator). We also observed that the B{sub inj} affects the ion confinement time, temperature, and density of electrons. All of the three parameters increase with increasing B{sub inj}.« less
  • Beam intensities of highly charged Ar ions (Ar{sup 11+,12+}) were measured as a function of plasma electrode position. We observed that the beam intensity of Ar{sup 11+,12+} increased when putting the electrode far from the electron-cyclotron-resonance zone. On the other hand, lower charged heavy ions (Ar{sup 8+,7+}) dramatically decreased. We observed that the intense beam extraction strongly affects the plasma condition. It may be due to the ion pumping effect.
  • We measured the beam oscillation of RIKEN 18 GHz electron cyclotron resonance ion source for various conditions. In this experiment, the frequency of the beam oscillation increases with increasing the gas pressure and decreases with increasing rf power. The oscillation frequency is strongly dependent on the negative voltage of biased disk, i.e., the frequency increases with increasing the negative voltage. We observed that the frequency is strongly dependent on the mass of ionized gas.
  • For RIKEN radio isotope beam project, we started to construct the new superconducting electron cyclotron resonance ion source (SC-ECRIS), which has an operational frequency of 28 GHz, in 2007. The main feature of this ion source is that we can produce large size of resonance zone with six sets of solenoid coils. Before starting, we intensively studied the effect of several key parameters of ECRIS (magnetic field configuration, microwave power density, negatively biased disk) on the plasma. In this article, we describe the effect of key parameters on the plasma and detailed structure of the new SC-ECRIS.