Engineering topics

Dolmatov, V. K.

Publications and source records attributed to Dolmatov, V. K..

3 records

DOE OSTI2018

Intershell-correlation-induced time delay in atomic photoionization

In this work, we predict an observable Wigner time delay in outer atomic shell photoionization near inner shell thresholds. The near-threshold increase of time delay is caused by intershell correlation and serves as a sensitive probe of this effect. The time delay increase is present even when the inner and outer shell thresholds are hundreds of electron volts apart. We illustrate this observation by several prototypical examples in noble gas atoms from Ne to Kr. In our study, we employ the random phase approximation with exchange and its relativistic generalization. We also support our findings by a simplified, yet quite insightful, treatment within the lowest-order perturbation theory.

74 ATOMIC AND MOLECULAR PHYSICS↗

DOE OSTI2018

Wigner–Eisenbud–Smith photoionization time delay due to autoioinization resonances

We report an empiric ansatz for the complex photoionization amplitude and Wigner-Eisenbud-Smith time delay in the vicinity of a Fano autoionization resonance are proposed to evaluate and interpret the time delay in the resonant region. The utility of this expression is evaluated in comparison with accurate numerical calculations employing the ab initio relativistic random phase approximation and relativistic multichannel quantum defect theory. The indisputably good agreement between corresponding results of the proposed model and results produced by the ab initio theories proves the usability of the model. In addition, the phenomenology of the time delay in the vicinity of multichannel autoionizing resonances is detailed.

relativistic random phase approximation↗

DOE OSTI2017

Angle-resolved Wigner time delay in atomic photoionization: The 4 d subshell of free and confined Xe

The angular dependence of photoemission time delay for the inner nd 3/2 and nd 5/2 subshells of free and confined Xe is studied in the dipole relativistic random phase approximation. A finite spherical annular well potential is used to model the confinement due to fullerene C 60 cage. Near cancellations in a variety of the dipole amplitudes, Cooper-like minima, are found. Overall, the effects of confinement on the angular dependence, primarily confinement resonances, are demonstrated and detailed.

74 ATOMIC AND MOLECULAR PHYSICS↗