Measurement of the lifetime and the proportion of (12)~C~(3+) ions in stored relativistic ion beams as a preparation for laser cooling experiments at the CSRe

摘要

We report on an experiment that was conducted in preparation of laser cooling experiments at the heavy-ion storage ring CSRe. The lifetimes of ion beams made up of (12)~C~(3+) and (16)~O~(4+) ions stored at an energy of 122 MeV/u in the CSRe were determined by two independent methods, firstly via a DC current transformer (DCCT) and secondly via a Schottky resonator. Using electron-cooling, the signals of the (12)~C~(3+) and (16)~O~(4+) ions could be separated and clearly observed in the Schottky spectrum. The obtained individual lifetimes of the (12)~C~(3+) and (16)~O~(4+) components were 23.6 s and 17.8 s, respectively. The proportion of (12)~C~(3+) ions in the stored ion beam was measured to be more than 70% at the beginning of the injection and increasing as a function of time. In addition to these measurements, the operation and remote control of a pulsed laser system placed directly next to the storage ring was tested in a setup similar to the one envisaged for future laser experiments.