Dramatic Changes in the <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mi mathvariant="italic">s</mi></math></span> Autoionization Process at the Beginning of the Ar <span class="sc">I</span> Sequence

P. van Kampen; G. O'Sullivan; V. K. Ivanov; A. N. Ipatov; J. T. Costello; E. T. Kennedy

doi:10.1103/PhysRevLett.78.3082

Dramatic Changes in the $3 s$ Autoionization Process at the Beginning of the Ar I Sequence

P. van Kampen, G. O'Sullivan, V. K. Ivanov, A. N. Ipatov, J. T. Costello, and E. T. Kennedy

Phys. Rev. Lett. 78, 3082 – Published 21 April 1997

Abstract

The $3 s \to np$ resonances were observed to change dramatically in appearance with increasing ionization along the Ar I sequence, and within the $3 s \to np$ channel of ${Ca}^{2 +}$ . By applying the Dyson equation method to positive ions for the first time, newly investigated double-electron processes were shown to play a crucial role in the interpretation of the resonance structure. The changes within the resonances result from their position relative to the Cooper minima in the 3s and 3p photoabsorption.