OPERATION OF THE ECR ION-SOURCE ALICE AND ITS PLATFORM

The operation of the electron cyclotron resonance (ECR) ion source Ali ce is described, with attention to the improved ion analysis and the n ew diagnostic equipment. Ion current peaks as small as tens of nA can be measured; resolving power is about 100. Routine operation is still restricted to gases, but prototypes of ovens have passed the first tes ts. Since currents are still rather Limited (about 400 nA for Xe-132(1 8+)), removable plasma chamber with increased inner diameter (63 mm), made in aluminum, is under construction. Preliminary analysis of charg e state distribution of xenon isotopes shows good fits with an approxi mately thermodynamical distribution; a sort of effective chemical pote ntial mu(c), is defined from fit parameters; in the particular case sh own here mu(c) congruent to 390 eV. A decision to install a high volta ge insulation transformer to allow platform operation up to V-p = 350 kV was made, and an adequate location is being found, with proper wall feedthroughs in design. (C) 1998 American Institute of Physics.