The Aarhus storage ring for ions and electrons ASTRID

ASTRID is a storage ring/synchrotron for ions and electrons. Results from the first 3 years of commissioning and running will be presented. A wide range of both positive and negative ions (both atomic and molecular) varying in mass from ³He to C₇₀ (Buckminster fullerene) have been stored in the ring. The physics has been centered-around laser-cooling, lifetime measurements of metastable ions and electron recombination. The ring is 2×3 months a year operational as a 580 MeV synchrotron radiation source (λ_c =35 Å), with stored currents (presently) around 150 mA. Initially beam-loading problems in the rf-cavity hindered large currents, but a fast feedback loop has circumvented this problem. Presently the current is limited by the injection rate at 100 MeV and the lifetime of the beam, at high currents influenced by ions trapped in the beam