Enhancement of electron–ion recombination rates at low energy range in the heavy ion storage ring CSRm<xref rid="cpb_29_3_033401fn1" ref-type="fn">*</xref><fn id="cpb_29_3_033401fn1"><label>*</label><p>Project supported by the National Key Research and Development Program of China (Grant No. 2017YFA0402300) and the National Natural Science Foundation of China (Grant Nos. U1932207, 11904371, and U1732133).</p></fn>

Enhancement of electron–ion recombination rates at low energy range in the heavy ion storage ring CSRm**

Project supported by the National Key Research and Development Program of China (Grant No. 2017YFA0402300) and the National Natural Science Foundation of China (Grant Nos. U1932207, 11904371, and U1732133).

Khan Nadir^{1, 2}, Huang Zhong-Kui¹, Wen Wei-Qiang^{1, 2, †}, Wang Shu-Xing³, Wang Han-Bing¹, Ma Wan-Lu³, Zhu Xiao-Long^{1, 2}, Zhao Dong-Mei¹, Mao Li-Jun^{1, 2}, Li Jie¹, Ma Xiao-Ming¹, Tang Mei-Tang¹, Yin Da-Yu¹, Yang Wei-Qing¹, Yang Jian-Cheng^{1, 2}, Yuan You-Jin^{1, 2}, Zhu Lin-Fan³, Ma Xin-Wen^{1, 2, ‡}

The absolute recombination rate coefficient for Be-like Ar¹⁴⁺, Li-like Ar¹⁵⁺, Be-like Ca¹⁶⁺, and F-like Ni¹⁹⁺ respectively. (a) Comparison of the experimental result to the theoretical calculations, the experimental data represented by connected black solid circles, the violet dashed line is for RR rate coefficient and the green line is from theoretical data of RR + DR. (b) Comparison of the experimental results with fitted data by taking into account of RR + DR resonances. Blue solid line corresponds to the fitting of DR. The red solid line indicates the fitted data including RR + DR, and Δ α is the enhancement of the experimental rate coefficient over the fitted rate coefficient α₀. The transverse and longitudinal temperature obtained from this fitting are k_BT_∥ = 2.40(6) meV and k_BT_⊥ = 11.91(87) meV for Ar¹⁴⁺ and k_BT_∥ = 0.8 meV, k_BT_⊥ = 40 meV for Ar¹⁵⁺ and Ca¹⁶⁺, and k_B T_∥ = 0.56(7) meV and k_BT_⊥ = 23(1) meV for Ni¹⁹⁺.