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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 17:57 |
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Conference: Bucharest University Faculty of Physics 2022 Meeting
Section: Theoretical Physics and Applied Mathematics
Title:
Photoionization dynamics of low Z ions near the first ionization threshold
Authors:
Cristian IORGA (1,2)
*
Affiliation:
1) National Institute for Laser Plasma and Radiation Physics, Atomistilor 409, P. O. Box MG-36, Magurele-Ilfov 077125, Romania
2) University of Bucharest, Faculty of Physics, Atomistilor 405, CP-MG 11, Magurele-Bucharest 077125, Romania
E-mail
criiorga@gmail.com
Keywords:
photoionization dynamics, resonant Auger, Dirac-Fock-Slater, time-dependent perturbation
Abstract:
The field-induced interference between the direct photoionization and resonant Auger processes is highly non-linear leading to different ionization dynamics regimes depending on laser pulse parameters relative to the atomic system of interest [1]. Due to their simplicity, atomic data of low Z ions are fairly accurate and can provide benchmark case tests for investigating the field-induced photoionization dynamics [2]. Despite requiring low photon energies, near-threshold ionization brings new complexity in the form non-local time-dependent terms that cannot be neglected [3] as well as rapid oscillating many-body interaction terms associated with the bound-free processes [4]. This work is part of a larger project investigating these non-local, highly oscillating effects on the photoionization dynamics of C III ion. Atomic data is computed using the Dirac-Fock-Slater model-potential [5] and the evolution of populations for different ion and free electron states is given within the time-dependent perturbation theory.
References:
[1] N. Rohringer and R. Santra, “Resonant Auger effect at high x-ray intensity”, Phys. Rev. A volume 77, 053404 (2008).
[2] J. Rothhardt, M. Bilal, R. Beerwerth, A.V. Volotka,V. Hilbert, T. Stöhlker, S. Fritzsche, J. Limpert, “Lifetime measurements of utrashort‐lived excited states in Be‐like ions”, X-ray Spectrometry volume 49(1), 165-168 (2019).
[3] P. V. Demekhin and L. S. Cederbaum, “Strong interference effects in the resonant Auger decay of atoms induced by intense x-ray fields”, Phys. Rev. A volume 83, 023422 (2011).
[4] I. P. Grant, “Relativistic quantum theory of atoms and molecules”, Springer Series on Atomic, optical, and plasma physics 40, 1-813 (2007).
[5] M. F. Gu, “The Flexible Atomic Code”, Can. J. Phys. volume 86(5), 675-689 (2008).
Acknowledgement:
Acknowledgement: This work has been supported by the Ministry of Research, Innovation and Digitalization, Romania, in the frame of Nucleus programme LAPLACE VI-contract 16N/2019. Partial financial support from the Institute of Atomic Physics under project FAIR is also acknowledged.
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