Intensity inversion between main and satellite lines in atomic photoionization

Area of Science:

• Atomic Physics
• Quantum Chemistry
• Photoelectron Spectroscopy

Background:

• Understanding electron correlation is crucial in atomic physics.
• Photoionization provides insights into electronic structure and transitions.
• Lithium (Li) atom serves as a fundamental system for studying these effects.

Purpose of the Study:

• Investigate 1s photoionization of atomic Li.
• Analyze the role of electron correlations in multielectron transitions (shake-up and conjugate shake-up).
• Compare these processes with direct photoionization (main lines).

Main Methods:

• Photoelectron spectroscopy was employed.
• Experiments were conducted in the photon energy range of 85–140 eV.
• Studied the ground state and excited states (Li(*) 1s(2)nl, nl=2p, 3s, 3p).

Main Results:

• Relative intensity of shake-up satellites increases with the initial excitation level of the Li atom.
• Shake-up processes dominate main lines for Li states with an n=3 valence electron.
• Wave function overlap between initial and final states explains the observed intensity changes for both shake-up and conjugate shake-up lines.

Conclusions:

• Electron correlations play a significant role in Li 1s photoionization, especially for excited states.
• The dominance of shake-up satellites for n=3 states highlights the importance of initial state excitation.
• Spatial overlap of wave functions is a key factor governing the intensity of satellite peaks.