Production of intense pulsed beams of highly charged ions from a superconducting electron cyclotron resonance ion source oleh L. X. Li, J. B. Li, J. D. Ma, H. Guo, B. Guo, D. Hitz, Y. C. Feng, W. Lu, J. W. Guo, X. Fang, R. N. Jin, Y. J. Yuan, L. T. Sun, H. W. Zhao