Determination of Nuclear Structure Effects on Atomic Spectra by Applying Rayleigh–Schr？dinger Perturbation Theory

In this work, we applied the first order time independent Rayleigh–Schr？dinger Perturbation Theory, as an approximation method to calculate numerically the corrections in atomic spectra due to nuclear structure effects. The results showed that the nuclear structure effects distort the atomic spectra in different ways: The combined fine structure effect which decreases with increasing values of n, split the quantum number n into l±？ and the magnitude of the energy levels shift is of order of 10-6 eV relative to the energy levels calculated from the non-relativistic Schrodinger equation. An energy level determined by the total angular momentum j of the orbiting electron are found to split further due to hyperfine structure effects with the energy difference of 5.9 × 10-6 eV. This corresponds to a wavelength is 21cm. The energy shift between 2 s 1/2 and 2 p 1/2 states due to the effects of vacuum fields on orbiting electron was calculated as 5.52 × 10-6 eV. We then continue to investigate the change in atomic spectra caused by the finite size nuclear structure effects. The finite-size nuclear structure effect on atomic spectra computed is of order of the scaling factors, ξ, ξ2 and ξ3 for n = 1, n = 2 and n = 3 atomic energy levels respectively. This showed that as the energy levels increased the effects of the finite – size nucleus on the orbiting electron is diminishing. Therefore the concept of finite nuclear size model has an extremely small impact on atomic spectra. These theoretical findings revealed some of the behavior of atomic spectra which may develop the understanding of spectroscopy and spectroscopic methods