C. Krantz, Elena-Oana Hanu, Mirko Looshorn, Athanasios Koutsostathis, Zoran Andelkovic, C. Brandau, Håkan Danared, С.В. Федотова, W. Geithner, Volker Hannen, F. Herfurth, R. Heß, W. Kaufmann, Ingrid Kraus, M. Lestinsky, E. Menz, Jon Roßbach, R. Schuch, Sergiy Trotsenko, G. Vorobyev, Michael Waider, Shu-Xing Wang, Stefan Schippers
Abstract We present developments at the electron cooler of the CRYRING@ESR storage ring aimed at improving its performance as internal target in low-energy electron–ion collision experiments. We describe recent modifications of the high-voltage and vacuum systems which lead to improved electron energy control and lower background count rates during such measurements. In a benchmark experiment on dielectronic recombination of F $$^\text {6+}$$ 6+ , we demonstrate that a spectroscopic resolution equivalent to transverse and longitudinal thermal electron energy spreads of $$\approx$$ ≈ 1 meV and $$\approx$$ ≈ 45 µeV, respectively, can be achieved under optimum conditions. This surpasses system performance observed previously in similar experiments.