• O. Tarvainen, J.E. Ärje, T. Kalvas, H. Koivisto, T. Ropponen, V. Toivanen, J.H. Vainionpää, A. Virtanen
  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 ac­cel­er­a­tor based ex­per­i­ments at JYFL (Uni­ver­si­ty of Jyväskylä, De­part­ment of Physics) range from basic re­search in nu­cle­ar physics to in­dus­tri­al ap­pli­ca­tions. A sub­stan­tial share of the beam time hours is al­lo­cat­ed for heavy ion beam cock­tails, used for ir­ra­di­a­tion tests of elec­tron­ics. Pro­duc­ing the re­quired ion beam cock­tails has re­quired ac­tive de­vel­op­ment of the JYFL ECR ion sources. This work is briefly dis­cussed to­geth­er with the im­pli­ca­tions of the beam cock­tail cam­paign to the beam time al­lo­ca­tion pro­ce­dure. The JYFL ion source group has con­duct­ed ex­per­i­ments on plas­ma physics of ECR ion sources in­clud­ing plas­ma po­ten­tial and time-re­solved bremsstrahlung mea­sure­ments, for ex­am­ple. The plas­ma physics ex­per­i­ments are dis­cussed from the point of view of beam cock­tail de­vel­op­ment.

Slides

• H. Koivisto, O. Tarvainen, T. Ropponen, M. Savonen, O. Steczkiewicz, V. Toivanen
  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.

Slides