The Heidelberg CSR: Stored Ion Beams in a Cryogenic Environment

Abstract

A cryogenic electrostatic ion storage ring CSR is under development at the Max‐Planck Institute for Nuclear Physics in Heidelberg, Germany. Cooling of the ultrahigh vacuum chamber is envisaged to lead to extremely low pressures as demonstrated by cryogenic ion traps. The ring will apply electron cooling with electron beams of a few eV up to 200 eV. Through long storage times of 1000 s as well as through the low wall temperature, internal cooling of infrared‐active molecular ions to their rotational ground state will be possible and their collisions with merged collinear beams of electrons and neutral atoms can be detected with high energy resolution. In addition storage of slow highly charged ions is foreseen. Using a fixed in‐ring gas target and a reaction microscope, collisions of the stored ions at a spead of the order of the atomic unit can be kinematically reconstructed. The layout and the cryogenic concept are introduced.