Performance and operation of advanced superconducting electron cyclotron resonance ion source SECRAL at 24 GHz

SECRAL (superconducting ECR ion source with advanced design in Lanzhou) ion source has been in routine operation for Heavy Ion Research Facility in Lanzhou (HIRFL) accelerator complex since May 2007. To further enhance the SECRAL performance in order to satisfy the increasing demand for intensive highly charged ion beams, 3–5 kW high power 24 GHz single frequency and 24 GHz +18 GHz double frequency with an aluminum plasma chamber were tested, and some exciting results were produced with quite a few new record highly charged ion beam intensities, such as ¹²⁹Xe³⁵⁺ of 64 eμA, ¹²⁹Xe⁴²⁺ of 3 eμA, ²⁰⁹Bi⁴¹⁺ of 50 eμA, ²⁰⁹Bi⁵⁰⁺ of 4.3 eμA and ²⁰⁹Bi⁵⁴⁺ of 0.2 eμA. In most cases SECRAL is operated at 18 GHz to deliver highly charged heavy ion beams for the HIRFL accelerator, only for those very high charge states and very heavy ion beams such as ²⁰⁹Bi³⁶⁺ and ²⁰⁹Bi⁴¹⁺, SECRAL has been operated at 24 GHz. The total operation beam time provided by SECRAL up to July 2011 has exceeded 7720 hours. In this paper, the latest performance, development, and operation status of SECRAL ion source are presented. The latest results and reliable long-term operation for the HIRFL accelerator have demonstrated that SECRAL performance for production of highly charged heavy ion beams remains improving at higher RF power with optimized tuning.