ECR ion source

The feasibility of using a 30-watt pulsed NdYAG laser to ablate or evaporate material directly into the ECR had some initial exploratory runs and produced two distinctly interesting results. This technique holds the possibility of using small quantities of material, with a high efficiency, and being applicable to all solids. The laser illuminates a sample through one of the radial ports in the ECR main plasma chamber. The off-line tests indicated that our surplus (free) laser is capable of ablating significant quantities of interesting materials. The first tests of the laser ablation idea were carried out using a bismuth sample. The inherent pulsed nature of the technique allowed us to immediately study the time evolution of charge states in the ECR plasma. The results are directly comparable to model calculations and are completely consistent with the sequential stepwise stripping process which was assumed to dominate the high charge state production process. A paper describing our results will be presented at the 1995 International Ion Source Conference.