New development of advanced superconducting electron cyclotron resonance ion source SECRAL (invited)

Abstract

Superconducting electron cyclotron resonance ion source with advance design in Lanzhou (SECRAL) is an 18-28 GHz fully superconducting electron cyclotron resonance (ECR) ion source dedicated for highly charged heavy ion beam production. SECRAL, with an innovative superconducting magnet structure of solenoid-inside-sextupole and at lower frequency and lower rf power operation, may open a new way for developing compact and reliable high performance superconducting ECR ion source. One of the recent highlights achieved at SECRAL is that some new record beam currents for very high charge states were produced by 18 GHz or 18+14.5 GHz double frequency heating, such as 1 e microA of (129)Xe(43+), 22 e microA of (209)Bi(41+), and 1.5 e microA of (209)Bi(50+). To further enhance the performance of SECRAL, a 24 GHz/7 kW gyrotron microwave generator was installed and SECRAL was tested at 24 GHz. Some promising and exciting results at 24 GHz with new record highly charged ion beam intensities were produced, such as 455 e microA of (129)Xe(27+) and 152 e microA of (129)Xe(30+), although the commissioning time was limited within 3-4 weeks and rf power only 3-4 kW. Bremsstrahlung measurements at 24 GHz show that x-ray is much stronger with higher rf frequency, higher rf power. and higher minimum mirror magnetic field (minimum B). Preliminary emittance measurements indicate that SECRAL emittance at 24 GHz is slightly higher that at 18 GHz. SECRAL has been put into routine operation at 18 GHz for heavy ion research facility in Lanzhou (HIRFL) accelerator complex since May 2007. The total operation beam time from SECRAL for HIRFL accelerator has been more than 2000 h, and (129)Xe(27+), (78)Kr(19+), (209)Bi(31+), and (58)Ni(19+) beams were delivered. All of these new developments, the latest results, and long-term operation for the accelerator have again demonstrated that SECRAL is one of the best in the performance of ECR ion source for highly charged heavy ion beam production. Finally the future development of SECRAL will be presented.

Progress in HIRFL-CSR

“…In order to get higher intensity from the injector, a high performance super-conducting ECR ion source SECRAL has also been developed [4]. …”

Production of highly charged ion beams with SECRAL

“…Since the commissioning in 2006-2007, SECRAL has been routinely and reliably delivering ion beams to the accelerators at IMP, 12 while the source R/D is therefore limited, that is, the great capability of the SECRAL source has not yet fully explored. In the past years, from time to time, techniques such as plasma chamber wall coating, aluminum chamber and DF heating have been applied to optimize the production of very high charge state ion beams.…”

Present status of storage rings at HIRFL

“…Present status of storage rings at HIRFL Youjin Yuan HIRFL has provided beams for experiments of 19 chemical elements with different isotopes. Benefiting from superconductive ECR source SECRAL [5,6], metallic and rare gas isotopes are supplied with high charge states. The blocks of Figure 2 that coloured in yellow and red indicate the elements accelerated in recent years at HIRFL, the red ones indicate those accelerated by CSRm.…”