JYFL, Jyväskylä
Funding: This work has been supported by the Academy of Finland under the Finnish Centre of Excellence Programme 2006-2011 (Nuclear and Accelerator Based Physics Programme at JYFL).
The activities of the JYFL ion source group cover the development of metal ion beams, improvement of beam transmission and studies of Electron Cyclotron Resonance Ion Source (ECRIS) plasma parameters. The development of metal ion beams is one of the most important areas in the accelerator technology. The low energy beam injection for K-130 cyclotron is also studied in order to improve its beam transmission. It has been noticed that the accelerated beam intensity after the cyclotron does not increase with the intensity extracted from the JYFL 14 GHz ECR ion source, which indicates that the beam transmission efficiency decreases remarkably as a function of beam intensity. Three possible explanations have been found: 1) the extraction of the JYFL 14 GHz ECRIS is not optimized for high intensity ion beams, 2) the solenoid focusing in the injection line causes degradation of beam quality and 3) the focusing properties of the dipoles (analysing magnets) are not adequate. In many cases a hollow beam structure is generated while the origin of hollowness remains unknown.
