Radiative Transitions between the ${4D^{10}5p^2(^3P_j)nl}$ and ${4D^{10}5s5p(^3P_1^o)nl}$ Autoionizing States of in Atom in Collisions of Slow Electrons with in$^{+}$ Ions

TL;DR

This study reports the first observation of radiative transitions between specific autoionizing states of indium atoms during slow electron collisions with In+ ions, revealing significant relativistic and correlation effects influencing decay probabilities.

Contribution

It provides new experimental data on dielectronic satellite lines and their excitation cross sections in indium, highlighting the role of relativistic and correlation effects in autoionizing state decay.

Findings

First observation of specific autoionizing state transitions in indium.

Effective excitation cross sections are comparable to ionic line cross sections.

Relativistic and correlation effects significantly increase radiation decay probabilities.

Abstract

The radiative transitions between the $4d^{10}5p^2(^3P_{0,1,2})nl$ and {$4d^{10}5s5p({}^3P_1^o)nl$ autoionizing} states of an indium atom that represent dielectronic satellites of the $4d^{10}5p^2 {}^3P_0 \to 4d^{10}5s5p {}^3P_1$ ($\lambda =171.7$ nm), $4d^{10}5p^2 {}^3P_1 \to 4d^{10}5s5p {}^3P_1$ ($\lambda =166.7$ nm), and $4d^{10}5p^2 {}^3P_2 \to 4d^{10}5s5p {}^3P_1$ ($\lambda =160.7$ nm) spectral lines of an In$^{+}$ ion have been observed for the first time. The energy dependences of the effective excitation cross sections of dielectronic satellites, as well as near-threshold regions of these spectral lines, were investigated in the range of electron energies 9$\div $15 eV with the help of the spectroscopic method using crossed beams of electrons and In$^{+}$ ions. The absolute excitation cross sections of dielectronic satellites amount to $(0.7\div 2)\times 10^{-16}$ cm$^{2}$ and are of the same order of magnitude as the effective excitation cross sections of the corresponding ionic lines. It is found that a considerable increase of the probability of radiation decay of the $4d^{10}5p^2(^3P_{0,1,2})nl$ autoionizing states of the In atom is related to strong relativistic and correlation effects, in particular to the configuration interaction of the $5p^2nl$ levels both with one another and with the levels of the $5s5dnl$ and $4d^95s^25p^2$ configurations.