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We study the effect of quantum interference on the structure and properties of spontaneous and stimulated transitions in a degenerate V-type three-level atom with an arbitrary total momentum of each state. Explicit expressions for the…

Quantum Physics · Physics 2007-05-23 A. A. Panteleev , Vl. K. Roerich

The new statistical approach for calculation of radiation processes with heavy multielectron ions in plasma is developed. The method consists in consideration of atomic structure as a condensed medium, characterized by the spectrum of…

The theory of collisional depolarization of spectral lines by atomic hydrogen (Derouich et al. \cite{derouich1}) is extended to $d$ $(l$=2) atomic levels. Depolarization rates, polarization and population transfer rates are calculated and…

Astrophysics · Physics 2009-11-07 M. Derouich , S. Sahal-Brechot , P. S. Barklem

Spectral lines emitted by plasmas provide information about the thermodynamic conditions, the degree of randomness or the interactions prevailing in the medium. Collisions by plasma electrons penetrating the extent of bound-electron…

Atomic Physics · Physics 2019-05-22 Jean-Christophe Pain , Franck Gilleron

Scattering and ionizing cross sections and rates are calculated for ultracold collisions between metastable helium atoms using a fully quantum-mechanical close-coupled formalism. Homonuclear collisions of the bosonic ${}^{4}$He$^{*}…

Atomic Physics · Physics 2019-07-03 D. G. Cocks , I. B. Whittingham , G. Peach

Interpretation of solar polarization spectra accounting for partial or complete frequency redistribution requires data on various collisional processes. Data for depolarization and polarization transfer are needed but often missing, while…

Solar and Stellar Astrophysics · Physics 2015-12-02 M. Derouich , A. Radi , P. S. Barklem

We calculate angle-resolved above-threshold ionization spectra for diatomic molecules in linearly polarized laser fields, employing the strong-field approximation. The interference structure resulting from the individual contributions of…

Atomic Physics · Physics 2009-11-13 H. Hetzheim , C. Figueira de Morisson Faria , W. Becker

We present a formalism for rigorous calculations of cross sections for inelastic and reactive collisions of ultracold atoms and molecules confined by laser fields in quasi-2D geometry. Our results show that the elastic-to-inelastic ratios…

Atomic Physics · Physics 2009-03-20 Z. Li , R. V. Krems

Within the framework of quantization of the macroscopic electromagnetic field, equations of motion and an effective Hamiltonian for treating both the resonant dipole-dipole interaction between two-level atoms and the resonant atom-field…

Quantum Physics · Physics 2016-08-16 Ho Trung Dung , Ludwig Knöll , Dirk-Gunnar Welsch

In this work we study the non-equilibrium dynamics of a quark-gluon plasma, as created in heavy-ion collisions. We investigate how big of a role plasma instabilities can play in the isotropization and equilibration of a quark-gluon plasma.…

High Energy Physics - Phenomenology · Physics 2008-11-18 Bjoern Schenke

We study cold heteronuclear atom ion collisions by immersing a trapped single ion into an ultracold atomic cloud. Using ultracold atoms as reaction targets, our measurement is sensitive to elastic collisions with extremely small energy…

Atomic Physics · Physics 2010-10-19 Christoph Zipkes , Stefan Palzer , Lothar Ratschbacher , Carlo Sias , Michael Köhl

Rate coefficients for inelastic Mg+H collisions are calculated for all transitions between the lowest seven levels and the ionic state (charge transfer). The rate coefficients are based on cross-sections from full quantum scattering…

Solar and Stellar Astrophysics · Physics 2015-06-04 P. S. Barklem , A. K. Belyaev , A. Spielfiedel , M. Guitou , N. Feautrier

We report the measurement of collision rate coefficient for collisions between ultracold Cs atoms and low energy Cs+ ions. The experiments are performed in a hybrid trap consisting of a magneto-optical trap (MOT) for Cs atoms and a Paul…

Atomic Physics · Physics 2020-08-20 Sourav Dutta , S. A. Rangwala

Interstellar hydrogen atoms (H atoms) penetrate into the heliosphere through the region of the solar wind interaction with the interstellar plasma due to their large mean free path. Resonant charge exchange of H atoms with protons has been…

Solar and Stellar Astrophysics · Physics 2025-04-22 A. V. Titova , V. V. Izmodenov , S. D. Korolkov

Low-energy inelastic collisions with neutral hydrogen atoms are important processes in stellar atmospheres, and a persistent source of uncertainty in non-LTE modelling of stellar spectra. We have calculated and studied excitation and charge…

Solar and Stellar Astrophysics · Physics 2019-05-24 A. M. Amarsi , P. S. Barklem

Ultracold polar molecules offer the possibility of exploring quantum gases with interparticle interactions that are strong, long-range, and spatially anisotropic. This is in stark contrast to the dilute gases of ultracold atoms, which have…

Atomic Physics · Physics 2015-05-18 K. -K. Ni , S. Ospelkaus , D. Wang , G. Quemener , B. Neyenhuis , M. H. G. de Miranda , J. L. Bohn , J. Ye , D. S. Jin

The predictive capability of a plasma discharge model depends on accurate representations of electron-impact collision cross sections, which determine the key reaction rates and transport properties of the plasma. Although many cross…

Plasma Physics · Physics 2024-10-14 Seung Whan Chung , Todd A. Oliver , Laxminarayan L. Raja , Robert D. Moser

The collision of two expanding plasma clouds is investigated, emphasizing instabilities and electron energization in the plasma mixing layer. This work is directly relevant to laboratory experiments with explosively-created laser or z-pinch…

Plasma Physics · Physics 2022-08-24 M. A. Malkov , V. I. Sotnikov

We investigate the interaction between two flat-top solitons within the cubic-quintic nonlinear Schr\"odinger equation framework. Our study results point towards a significant departure of flat-top solitons collisional characteristics from…

Pattern Formation and Solitons · Physics 2024-10-25 U. Al Khawaja , M. O. D. Alotaibi , L. Al Sakkaf

Interactions between photons and electrons are ubiquitous in astrophysics. Photons can be down scattered (Compton scattering) or up scattered (inverse Compton scattering) by moving electrons. Inverse Compton scattering, in particular, is an…

High Energy Astrophysical Phenomena · Physics 2023-04-05 Anderson C. M. Lai , Kenny C. Y. Ng