Dielectronic recombination (DR) is a two-step process. In the first step, a free electron is radiationlessly captured by an ion Aq+, the excess energy is used to excite a bound electron in the ion core simultaneously, by which a doubly excited intermediate state of the ion is formed. In the second step, the intermedia state stabilizes via emission photons.
The main cooler storage ring (CSRm) equipped with a 35 kV electron cooler (EC-35) which provides a broad detuning energy range of ±3 kV corresponding to relative energy at the center of mass frame to be ~100 eV. By scanning the electron energy at the cathode of electron cooler and detecting the recombined ion beams after the first dipole magnet downstream the electron cooler EC-35, the DR spectrum can be measured. DR spectrum can be used to investigate the atomic structure and plasma rate coefficients related to astrophysics.
