An ECR charge breeder is an ion source where we inject a monocharged ion beam in order to multi-ionize it. The first application of such a device concerns the production of accelerated radioactive ion beams, accelerators presently built worldwide to extend the research objectives of nuclear physics. More recently, we have pointed out that the charge breeding method was like a probe allowing significant progresses in the fundamental knowledge about physics involved in ECR ion sources.
The principle of the method is the following: a monocharged ion beam is extracted from a 1+ ion source (simple technology, low cost), after its selection by a magnetic spectrometer, it is transported towards an ECR ion source opened at the injection side. The energy of this incoming beam is adjusted in such a way it can be decelerated into the source and then captured by the plasma of this latter. The objective is to maximize the capture process and to minimize the time of the multi-ionization process, in order to extract, with the highest efficiency, multicharged ion beams of the same nature than the incoming beam. The ion source team has developed the ECR charge breeder technique for more than 15 years. This method was invented at LPSC, and then has been improved with the development of the PHOENIX ECR charge breeder. Besides the internal characteristics of the method, the important points to measure are the intensity acceptance, the emittance of the extracted n+ beams, the possible impurities intensities superimposed to the specific n+ beam selected, and the maintenance issues of the charge breeder. More than 30 ions beams of different chemical nature or isotopic state, extracted from various 1+ ion sources have been tested (He, N, Ne, Na, Mg, Al, S, Ar, Rb, Sr, Y, Ag, In, Sn, Xe, Cs, Ba, La, Pb, Bi, U).The PANTECHNIK french firm has sold two of these devices, one of them equip the TRIUMF-ISAC accelerator in Vancouver (Canada), the other one will be installed at GANIL in the frame of the SPIRAL1 upgrade.
The LPSC ECR charge breeder