类氖等电子系列离子基态的双电子复合速率系数研究  

The study of dielectronic recombination (DR) rate coefficient for ground state of Ne-like isoelectronic sequence ions

作　　者：杨建会[1] 范强[1] 张建平[1] 

机构地区：[1]乐山师范学院物理与电子工程学院,乐山614004

出　　处：《物理学报》2012年第19期123-130,共8页Acta Physica Sinica

基　　金：四川省教育厅项目(批准号:10ZC109);乐山师范学院项目(批准号:Z1165);四川省科技厅项目(批准号:2011JYZ005)资助的课题~~

摘　　要：使用全相对论组态相互作用方法,能级-能级细致计算了0.1E_I≤kT_e≤10E_I(E_I是类钠离子基态的第一电离能)温度范围内类氖离子基态双电子复合(DR)速率系数,双激发自电离能级考虑了(2s2p)~73ln'l',(2s2p)~74l4l'以及(2s2p)~74l5l'组态.对于(2s2p)~73ln'l'双激发自电离组态,轨道角量子数l'>8的(2s2p)~73ln'l'双激发自电离态对双电子复合速率系数的贡献可以忽略不计;(2s2p)~73ln'l'双激发自电离组态的高里德堡态对双电子复合速率系数的贡献满足n'^(-3)组态-组态外推法,并且核电荷数越大,趋于n'^(-3)标度的n'值越小;对细致能级计算得到的类氖离子基态的总DR速率系数进行了拟合,得到类氖离子基态的总DR速率系数随核电荷数Z和电子温度变化的经验公式,该拟合公式与细致计算结果的偏差在2%以内,能较准确的计算任意核电荷数Z的类氖离子在0.1E_I≤kT_e≤10E_I电子温度范围的DR速率系数.Burgess-Merts(BM)近似公式不适用于估算低温(kT_e<0.3E_I)类氖离子的DR速率系数,在高温(kT_e>2E_I)时,类氖离子的DR速率系数可以用BM近似公式表示.The dielectronic recombination （DR） rate coefficients for Ne-like isoelectronic sequence ions in the ground state 2s22p6 are calculated by using relativistic configuration interaction （RCI） method over a wide temperature ranging from 0.1EI to 10EI where EI is the ionization energy of corresponding Na-like ion. The （2s2p）73ln′l′, （2s2p）74l4l′ and （2s2p）74l5l′ complexes are considered as autoionizing doubly excited states of Ne-like ions in the calculation. The contribution of （2s2p）73ln′l′ complex with l′ 〉 8 is found to be negligible. The contribution of high Rydberg states of （2s2p）73ln′l′ complex obeys the complex-complex n′-3 extrapolation, and the larger the nuclear charge, the smaller the value of n′ is. On the basis of the detailed level-by-level results, a general analytic formula for the total DR rate coefficient for all the ions along the Ne-like isoelectronic sequence is constructed. This formula can generally reproduce the calculated DR rate coefficients within 2% for electron temperature between 0.1EI and 10EI. Burgess-Merts semiempirical formula is found to be inadequate for predicting the DR rates of Ne-like ions at low electron temperatures （kTe 〈 0.3EI） and may be used for high electron temperatures （kTe 〉 2EI）.

关 键 词：相对论组态相互作用 双电子复合 类氖离子 速率系数 

分 类 号：O562.4[理学—原子与分子物理]