Spectroscopy and Collision Theory. II. The Ar Absorption Spectrum

A collision-type formalism for spectral theory, described by Lu and applied originally to Xe, is improved and is applied to analyze the strongly perturbed absorption spectrum of Ar. The analysis expresses experimental data in terms of three sets of empirical parameters: five eigenquantum defects ${\mu }_{\alpha }$, one 5 × 5 orthogonal transformation matrix ${\updownarrow \updownarrow }_{i\alpha }$, and five dipole matrix elements $D_{\alpha }$. The energy dependence of the parameters is studied and is found to be approximately linear for the ${\mu }_{\alpha }$ and insignificant for ${\updownarrow \updownarrow }_{i\alpha }$ and $D_{\alpha }$. With these parameters thus determined by fitting to the experimental data, the mixing coefficients of the Rydberg levels have been determined and their oscillator strength have been predicted and compared with available experimental data.