Operational experience with the electrostatic storage ring, Elisa

The design and initial operation of the first ion storage ring using electrostatic deflection and focusing elements has been previously described. In the present contribution, the design will be only briefly described, and emphasis will be given to the operational experience with the storage ring. At the time of writing this contribution, different beams of both positive and negative atomic and molecular ions of masses ranging from 4 to 840 AMU's have been stored. The residual-gas pressure, which in the best cases has been below 10/sup -11/ mBar, determines the lifetimes of low-intensity beams of stable ions. Lifetimes up to more than 30 seconds have been observed. Intensity-related losses of beam are observed when the number of injected particles is higher than a few times 10/sup 5/. These losses are not understood at present. Future research programs will be outlined, including storage of very heavy bio-molecules.