Author: Becker, R.
Paper Title Page
MOPPH006 Direct Injection of Intense Heavy Ion Beams from a High Field ECR Ion Source into an RFQ 52
 
  • G.O. Rodrigues, D. Kanjilal
    IUAC, New Delhi, India
  • R. Becker
    IAP, Frankfurt am Main, Germany
  • R.W. Hamm
    R&M Technical Enterprises, Pleasanton, California, USA
 
  Beam intensities achievable from high performance ECR sources for highly charged ions are limited by the high space charge. For high performance ECR sources, the stray magnetic field of the source can provide focusing against the space charge blow-up of the beam in addition to the Direct Plasma Injection Scheme (DPIS) adapted from laser ion sources*. A combined extraction/matching system** has been designed for direct injection into a radio frequency quadrupole (RFQ) accelerator, allowing a total beam current of 10 mA for the production of highly charged 238U40+ (1.33 mA) to be injected at an ion source voltage of 60 kV. In this design, the features of IGUN have been used to take into account the rf-focusing of an RFQ channel (without modulation), the electrostatic field between ion source extraction and the RFQ vanes, the magnetic stray field of the ECR superconducting solenoid, and the defocusing space charge of an ion beam. The RFQ has been designed to suppress neighbouring charge states and to work as a filter for the desired 238U40+. This reduces the transport problem for the beam line as well as it reduces the emittance for the selected charge state.
* R. Becker et al., PROC. EPAC-2004, TUPLT024
** G.Rodrigues et al., Rev. Sci.Instrum. 85,02A740 (2014)