Performance of an ECR ion source using liquid-helium-free superconducting solenoid coils (SHIVA)

The operation of the liquid-helium-free superconducting electron cyclotron resonance ion source SHIVA at University of Tsukuba had been started in the summer of 2000. To evaluate the potential and the performance of the source, we measured intensities of highly charged Xe ions with conditioning and optimizing several operating parameters. We also measured dependencies of beam intensities on various parameters of the source. Through optimization processes of the source, we successfully produced intense beam of highly charged Xe ions. Some of the best results (6 and 4 emuA for Xe32+ and Xe33+) were obtained at the injected microwave power of 770 W and the extraction voltage of 15 kV. SHIVA has now achieved an outstanding level of performance of delivering highly charged ion beams. In this paper, detailed descriptions of SHIVA's performance are reported and the reasons why SHIVA excels in the production of highly charged ions are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.