Accurate Theoretical Atomic Cross Sections (Physics)

简单带电粒子与原子的相互作用 将在扰动系列的框架内进行研究 approach. 第一个基本问题是， 摄动级数的收敛性及其在实际中是否 可以计算精确的理论截面。 的 工作的第二个方面将涉及这些应用 当前感兴趣的具体问题，包括 钠的电子激发，弹性正电子散射， 电子碰撞电离和电子-光子同步电离 激发 二阶振幅用 Dalgarno和刘易斯的方法;问题是， 畸变绿色函数的特定选择可以是 发现这将优化收敛速度， 微扰级数

The interactions between simple charged particles and atoms will be examined within the framework of a perturbation series approach. A first and fundamental question concerns the rate of convergence of perturbation series and whether it is in practice possible to calculate accurate theoretical cross sections. The second aspect of the work will involve the application of these techniques to specific problems of current interest, including electron excitation of sodium, elastic positron scattering, electron impact ionization, and simultaneous electron-photon excitation. Second order amplitudes are evaluated with the method of Dalgarno and Lewis; the question is whether a particular choice for the distorted Green's function can be found which will optimize the rate of convergence of perturbation series.