ARSENY: A program for computing inelastic transitions via hidden crossings in one-electron atomic ion-ion collisions with classical description of nuclear motion
ARSENY: A program for computing inelastic transitions via hidden crossings in one-electron atomic ion-ion collisions with classical description of nuclear motion
复制标题
ARSENY：一种通过单电子原子离子-离子碰撞中的隐藏交叉计算非弹性跃迁的程序，并具有核运动的经典描述
DOI：
10.1016/j.cpc.2023.108662
复制
发表时间：
2023
期刊：
影响因子：
--
通讯作者：
S. Vinitsky
中科院分区：
文献类型：
--
作者：
A. Gusev;E. A. Solov’ev;S. Vinitsky
ASHNY程序用于计算慢速单电子原子离子-离子碰撞中通过隐藏交叉点的非弹性跃迁截面，使用碰撞能区E<；20kev/核子中核运动的经典描述的近似。着重计算了双中心库仑问题的绝热势能曲线对于核间距复值的解析性质。计算了复杂的分支点和隐藏交叉点，揭示了它们对单电子碰撞系统动力学的重要意义。本文给出了He~(2+)+H(1 S)慢碰撞中电荷交换、激发和电离截面的基准计算，并与实验数据进行了比较。计划摘要计划标题：阿尔谢尼CPC库链接到计划文件：https://doi.Org/10.17632/n43srxwdnm。1许可条款：CC by 4.0程序设计语言：Fortran 90/95。编译器：英特尔(R)可视化Fortran编译器19.0。4.245[IA-32]问题的性质：低温等离子体中单电子原子离子-离子碰撞中的电荷交换、激发和电离过程是天体物理学和热核实验堆托卡马克电荷交换复合光谱边缘诊断领域的活跃研究课题[1-7]。在核运动的经典描述的近似下，单电子慢原子离子-离子碰撞的电荷交换、激发和电离截面的数值计算通常是通过电子-核动力学方法[8]和使用双中心库仑问题的基函数的紧耦合通道方法(例如，见[9-13])实现的。然而，在实数核间距的情况下，这些方法不能考虑双中心库仑问题中离散-离散和离散-连续跃迁的动力学结构。这一缺点表现在离子速度较小时理论截面和实验截面之间的不一致[13-15]。在许多文献[1，14，16-20]中，当使用对核间距离的复平面的解析延拓时，通过势曲线的隐藏交叉来考虑相变的动力学结构。这一方法是在ASHNY程序中实现的，该程序的目的是在文献[1]中公布的经典核运动描述的近似范围内，通过单电子原子离子-离子慢碰撞的隐藏交叉点计算非弹性离散-离散和离散-连续相变的截面。本文给出了He~(2+)+H(1 S)慢碰撞中电荷交换、激发和电离截面的基准计算，并与实验数据进行了比较。求解方法：从对应于一对非线性方程的二次型泛函的最小化条件出发，通过使用均方最小二乘法迭代三项递推关系[21，22]，计算出双中心库仑问题的势能曲线E=E(R)和依赖于实值和复值参数R的分离常数λ=λ(R)。这些方程是从已知的准径向和准角球面库仑函数展开系数的递推关系中得到的。在核间距离R的复平面中寻找的分支点系列Rc和复势能曲线E(R)的隐藏交叉点E(R)通过使用以差分E(R)−E(Rc…)的平方根形式的已知解析行为的迭代方法来计算
The ARSENY program is intended to compute cross-sections of inelastic transitions via hidden crossings upon slow one-electron atomic ion–ion collisions using the approximation of classical description of nuclear motion in the collision energy region E< 20 KeV/nucleon. Particular attention is paid to the calculation of the analytical properties of adiabatic potential energy curves of the two-center Coulomb problem for complex values of the internuclear distance. Complex branch points and hidden crossings are calculated and their significance for the dynamics of one-electron collisional systems is revealed. Benchmark calculations of cross sections for charge exchange, excitation, and ionization in slow He 2++ H (1 s) collisions are presented and compared with experimental data. Program summary Program Title: ARSENY CPC Library link to program files: https://doi. org/10.17632/n43srxwdnm. 1 Licensing provisions: CC By 4.0 Programming language: FORTRAN 90/95. Compilers: Intel (R) Visual Fortran Compiler 19.0. 4.245 [IA-32] Nature of problem: The processes of charge exchange, excitation, and ionization in one-electron atomic ion–ion collisions in a low-temperature plasma are actively studied in astrophysics and tokamak Charge-eXchange Recombination Spectroscopy (CXRS) Edge diagnostics in ITER [1–7]. Numerical calculations of cross sections for charge exchange, excitation, and ionization for slow one-electron atomic ion–ion collisions within the approximation of classical description of nuclear motion have been conventionally implemented, in particular, by the electron-nuclear dynamics approach [8] and the close-coupled channel method using basis functions of the two-center Coulomb problem (see, eg,[9–13]). However, with real-valued internuclear distance these approaches did not allow for the dynamical structure of discrete-discrete and discrete-continuous transitions in the two-center Coulomb problem. This disadvantage manifests itself in the disagreement between the theoretical and experimental cross-sections at small velocity of ions [13–15]. In a number of papers [1, 14, 16–20] the dynamical structure of the transitions is considered in terms of hidden crossing of potential curves, when using the analytic continuation to a complex plane of the internuclear distance. This approach is implemented in the ARSENY program aimed at computing cross sections of inelastic discrete-discrete and discrete-continuous transitions via hidden crossings for slow one-electron atomic ion–ion collisions within the approximation of classical description of nuclear motion announced in [1]. Benchmark calculations of cross sections for charge exchange, excitation, and ionization in slow He 2++ H (1 s) collisions are presented and compared with experimental data. Solution method: The potential energy curves E= E (R) and the separation constant λ= λ (R) depending on the real-valued and complex-valued parameter R of the two-center Coulomb problem are calculated from the minimization condition for a quadratic functional corresponding to a pair of nonlinear equations with respect to a pair of unknowns E (R) and λ (R) by iterating three-term recurrent relations [21, 22] using a mean least square method [23]. These equations are obtained from the known recurrent relations for the expansion coefficients of quasiradial and quasiangular spheroidal Coulomb functions. The series of branching points R c sought for in the complex plane of internuclear distance R and the hidden crossings of complex potential energy curves E (R) are calculated by an iterative method using the known analytical behavior in the form of a square root of difference E (R)− E (R c …