Radiation Effects & Defects in Solids Vol. 160, Nos 10–12, October–December 2005, 715–722 Flashback and perspectives for the production of intense ion beams with ECR ion sources S. GAMMINO*†, G. CIAVOLA†, F. CONSOLI†, S. BARBARINO‡, L. CELONA† and D. MASCALI† †INFN-LNS, Catania, Italy ‡Dipartimento di Fisica e Astronomia, Università di Catania, Italy There is a clear evidence that the combination of ability to produce intense beams of highly charged heavy ions and of reliability, stability and low emittance can be guaranteed only by an adequate design of electron cyclotron resonance ion sources (ECRIS). Following the roadmap defined by Geller’s scaling laws (1987) and the high B-mode concept (1990), the evolution of ECRIS has been steady and it amounted to about one order of magnitude per decade, as for high charge state currents. A further increase is possible according to the standard model of ECR sources unless technological problems may limit it in the future. Some sources are in the commissioning or construction phase to get the milliampere level for highly charged heavy ions, and some limitations have been already found but the possibility to get a further step forward remains unchanged. This paper presents the flashbacks of previous relevant experiences, along with the perspectives for higher current production in the years after 2010. Keywords: ECR; Ion beam; Ion sources; Charge state 1. Electron cyclotron resonance ion sources’ scaling laws and the high B-mode concept When microwaves are injected into a gas-filled chamber in the presence of high magnetic field, a plasma discharge may be triggered by the energy transfer between microwaves and free electrons. The electron’s momentum is increased by the microwave field to the extent that collisions with neutral atoms lead to the ionization of the gas; the plasma is sustained in the presence of an adequate magnetic field. The magnetic field introduces different coupling mechanisms and, depending on its value, two different types of plasma can be generated, off-resonance heating (if the magnetic trap field B max exceeds the resonance field B ECR everywhere in the plasma chamber) or electron *Corresponding author. Email: gammino@lns.infn.it Radiation Effects & Defects in Solids ISSN 1042-0150 print/ISSN 1029-4953 online © 2005 Taylor & Francis http://www.tandf.co.uk/journals DOI: 10.1080/10420150500493378