ION-SOURCE STUDIES AT THE ORNL ECR SOURCE FACILITY

Using high resolution magnetic analysis, we have measured energy spreads of Ar+q (1<q<12) ion beams extracted from the ORNL ECR ion source under a number of different ECR plasma conditions. The measured energy spreads for the different charge states fall in the range 8-20 eV per charge and are all roughly proportional to the ion charge. In addition, we have used a combination of magnetic and electrostatic analysis to investigate the high charge state tail of the extracted Ar+q charge state distribution. Charge states up to +16 have been positively identified; in addition, tentative identification of extracted Ar+17 ions has been made, with total intensity in the range of 10-20 kHz.