Development of a 1+ /N+ setup for the production of multicharged radioactive alkali ions in SPIRAL
Résumé
In the framework of the production of radioactive ion beams by the isotope separator online method, a new system has been developed at GANIL/SPIRAL I to produce multicharged alkali ions. The principle, referred to as the “direct 1 + /N+ method,” consists of a surface ionization source associated with a multicharged electron-cyclotron-resonance ion source without an intermediate mass separator. This new system has been tested online using a 48Ca primary beam at 60.3 A MeV. The experimental evidence of the direct 1 + /N+ process has been obtained for a potential difference between the two sources of 11 V and with a 1 + /N+ charge breeding efficiency of 0.04% for 47K5+. This value is significantly lower than the value of 6% obtained for stable K ions with the standard 1 + /N+ method. A possible explanation is given in the text.