Electron-ion recombination of Be-like Ca

Electron-ion recombination rate coefficients of Be-like Ca in the center of mass energy from 0 to 51.88 eV have been measured by means of merged-beam technique at the main cooler storage ring (CSRm). The calculation conducted with AUTOSTRUCTURE code was also presented and compared with the experimental results. Dielectronic recombination associated with 2s² [¹S₀] → 2s2p [³P_0,1,2, ¹P₁] and trielectronic recombination associated with 2s² [¹S₀] → 2p² [³P_0,1,2, ¹D₂, ¹S₀] transitions have been measured. In addition, recombination of parent ions at the 2s2p ³P₀ meta-stable state has also been identified from the measured spectrum. Plasma recombination rate coefficients in the temperature range of 10³-10⁸ K were derived from the measured recombination rates and compared with the results from the AUTOSTRUCTURE code as well as previous calculations. An agreement of better than 25% iss found for the collisionally ionized plasmas while the discrepancies are higher for photo-ionized plasmas. (author)