CYCLOTRONS 2010 - List of Authors (Celona, L.)

Paper	Title	Page
MOPCP050	Studies of ECRIS Ion Beam Formation and Quality at the Department of Physics, University of Jyväskylä	153
	V.A. Toivanen, V.P. Aho, J.E. Ärje, J.A. Kauppinen, H. A. Koivisto, O.A. Tarvainen JYFL, Jyväskylä, Finland L. Celona, G. Ciavola, S. Gammino, D. Mascali INFN/LNS, Catania, Italy A. Galatà INFN/LNL, Legnaro (PD), Italy T. Ropponen NSCL, East Lansing, Michigan, USA
	During the last couple of years a lot of effort has been put into studies concerning the ion beam formation and beam quality of electron cyclotron resonance ion sources (ECRISs) at the Department of Physics, University of Jyväskylä (JYFL). The effects of microwave frequency fine tuning on the performance of JYFL 14 GHz ECRIS have been studied with multiple experiments in collaboration with INFN-LNS (Instituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud). Also, a number of measurements have been carried out to study the effects of space charge compensation of ion beams on the beam quality. In order to proceed further with these studies, a modified version of the beam potential measurement device developed at LBNL (Lawrence Berkeley National Laboratory) is under development. Simulations are used to study the possibility to improve the beam quality by biasing the beginning of the beam line upstream from m/q separation. With high voltage biasing the beam energy could be increased temporarily over the limit of the injection system of the accelerator. Latest results and current status of these projects will be presented and discussed.

WEM1CIO03	New Tools for the Improvement of Beam Brightness in ECR Ion Sources	327
	S. Gammino, L. Celona, G. Ciavola, D. Mascali INFN/LNS, Catania, Italy
	According to the model that has driven the development of ECRIS in the last years, a large variation of the pumping microwave frequency (order of GHz) along with the proportional increase of the magnetic field boosts the extracted current for each charge state because of a larger plasma density. Recent experiments have demonstrated that even slight frequency's changes (of the order of MHz) considerably influence the output current, and what's more important, even the extracted beam properties (beam shape, brightness and emittance) are affected. A number of tests have been carried out in the last few years and they will be reviewed along with the results of numerical simulations which are able to explain the observed phenomena. The frequency has been systematically changed and the beam output has been recorded either in terms of charge state distributions and beam emittance. The detected bremsstrahlung X-rays are additionally analysed: they give insights about the electron energy distribution function (EEDF). An overview about the possible future improvements of ECR ion source will be given.

Paper

Title

Page

Studies of ECRIS Ion Beam Formation and Quality at the Department of Physics, University of Jyväskylä

153

V.A. Toivanen, V.P. Aho, J.E. Ärje, J.A. Kauppinen, H. A. Koivisto, O.A. Tarvainen
JYFL, Jyväskylä, Finland
L. Celona, G. Ciavola, S. Gammino, D. Mascali
INFN/LNS, Catania, Italy
A. Galatà
INFN/LNL, Legnaro (PD), Italy
T. Ropponen
NSCL, East Lansing, Michigan, USA

During the last couple of years a lot of effort has been put into studies concerning the ion beam formation and beam quality of electron cyclotron resonance ion sources (ECRISs) at the Department of Physics, University of Jyväskylä (JYFL). The effects of microwave frequency fine tuning on the performance of JYFL 14 GHz ECRIS have been studied with multiple experiments in collaboration with INFN-LNS (Instituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud). Also, a number of measurements have been carried out to study the effects of space charge compensation of ion beams on the beam quality. In order to proceed further with these studies, a modified version of the beam potential measurement device developed at LBNL (Lawrence Berkeley National Laboratory) is under development. Simulations are used to study the possibility to improve the beam quality by biasing the beginning of the beam line upstream from m/q separation. With high voltage biasing the beam energy could be increased temporarily over the limit of the injection system of the accelerator. Latest results and current status of these projects will be presented and discussed.

WEM1CIO03

New Tools for the Improvement of Beam Brightness in ECR Ion Sources

327

S. Gammino, L. Celona, G. Ciavola, D. Mascali
INFN/LNS, Catania, Italy

According to the model that has driven the development of ECRIS in the last years, a large variation of the pumping microwave frequency (order of GHz) along with the proportional increase of the magnetic field boosts the extracted current for each charge state because of a larger plasma density. Recent experiments have demonstrated that even slight frequency's changes (of the order of MHz) considerably influence the output current, and what's more important, even the extracted beam properties (beam shape, brightness and emittance) are affected. A number of tests have been carried out in the last few years and they will be reviewed along with the results of numerical simulations which are able to explain the observed phenomena. The frequency has been systematically changed and the beam output has been recorded either in terms of charge state distributions and beam emittance. The detected bremsstrahlung X-rays are additionally analysed: they give insights about the electron energy distribution function (EEDF). An overview about the possible future improvements of ECR ion source will be given.