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Related papers: Electron impact double ionization of helium from c…

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We account for the different symmetries of the 2^{1,3}S helium excited states in a quasiclassical description of the knockout mechanism augmented by a quantum shakeoff contribution. We are thus able to formulate the separate contribution of…

Atomic Physics · Physics 2009-11-10 A. Emmanouilidou , T. Schneider , J. -M. Rost

A comprehensive compilation of experimental K-shell ionization cross sections induced by electron impact has been assembled, including results up to December 2024. The data are organized according to the target atomic number and to the…

Helium (He) is the ideal atom to perform tests of ab-initio calculations in two-electron systems that consider all known effects, including quantum-electrodynamics and nuclear-size contributions. Recent state-of-the-art calculations and…

Atomic Physics · Physics 2025-01-07 Gloria Clausen , Kai Gamlin , Josef A. Agner , Hansjürg Schmutz , Frédéric Merkt

We report measurements of electron impact ionization (EII) for Fe^13+, Fe^16+, and Fe^17+ over collision energies from below threshold to above 3000 eV. The ions were recirculated using an ion storage ring. Data were collected after a…

Calculations are performed for electron collision with the methylene molecular ion CH$_2^+$ in its bent equilibrium geometry, with the goal to obtain cross sections for electron impact excitation and dissociation. The polyatomic version of…

Plasma Physics · Physics 2024-05-22 K. Chakrabarti , J. Zs Mezei , I. F. Schneider , J. Tennyson

As a step toward the full \emph{ab-initio} description of two-photon double ionization processes, we present a finite-pulse version of the virtual-sequential model for polyelectronic atoms. The model relies on the \emph{ab initio}…

Atomic Physics · Physics 2023-08-02 Siddhartha Chattopadhyay , Carlos Marante , Barry Schneider , Luca Argenti

We formulate a general three-dimensional semiclassical model for the study of correlated multielectron escape during fragmentation of molecules driven by intense infrared laser pulses, while fully accounting for the magnetic field of the…

Atomic Physics · Physics 2023-11-30 Georgios Petros Katsoulis , Matthew Benjamin Peters , Agapi Emmanouilidou

By performing an ensemble of molecular dynamics simulations, the model-dependent ionisation state is computed for strongly interacting systems self-consistently. This is accomplished through a free energy minimisation framework based on the…

In the semiclassical picture of photoionization process in intense laser fields, the ionization rate solely depends on the amplitude of the electric field and the final photoelectron momentum corresponds to the instant of ionization of the…

Atomic Physics · Physics 2019-05-09 Li Guo , Shilin Hu , Mingqing Liu , Zheng Shu , Xiwang Liu , Jie Li , Weifeng Yang , Ronghua Lu , Shensheng Han , Jing Chen

The cross sections for single-electron photo-ionisation in two-electron atoms show fluctuations which decrease in amplitude when approaching the double-ionisation threshold. Based on semiclassical closed orbit theory, we show that the…

Atomic Physics · Physics 2009-11-13 Chang Woo Byun , Nark Nyul Choi , Min-Ho Lee , Gregor Tanner

In this communication, we present the results of the Five-fold Differential Cross Section (5DCS) and Triple Differential Cross Section (TDCS) for the (e,2e) process on molecular hydrogen ($H_2$) by the plane wave and the twisted electron…

Atomic Physics · Physics 2021-02-03 Nikita Dhankhar , Rakesh Choubisa

Triple-differential cross sections for two-photon double ionization of molecular hydrogen are presented for a central photon energy of 30 eV. The calculations are based on a fully {\it ab initio}, nonperturbative, approach to the…

Atomic Physics · Physics 2016-11-17 Xiaoxu Guan , Klaus Bartschat , Barry I. Schneider

We present a comprehensive study of electron collisions with calcium atoms by using the convergent \emph{B}-spline \emph{R}-matrix method. Elastic, excitation, and ionization cross sections were obtained for all transitions between the…

Atomic Physics · Physics 2019-01-16 Oleg Zatsarinny , Henry Parker , Klaus Bartschat

Hyperspherical partial wave theory has been applied here in a new way in the calculation of the triple differential cross sections for the ionization of hydrogen atoms by electron impact at low energies for various equal-energy-sharing…

Atomic Physics · Physics 2009-11-07 J. N. Das , S. Paul , K. Chakrabarti

We formulate a three-dimensional semi-classical model to address triple and double ionization in three-electron atoms driven by intense infrared laser pulses. During time propagation, our model fully accounts for the Coulomb singularities,…

Atomic Physics · Physics 2022-04-20 M. B. Peters , G. P. Katsoulis , A. Emmanouilidou

The original binary-encounter Bethe model of Kim and Eugene Rudd (1994 Phys. Rev. A 50 3954-67) has proven to be an accurate analytical representation of total impact ionisation cross sections of electrons colliding with atoms and…

Atomic Physics · Physics 2026-03-12 Anthony Jeseněk , Alejandro Luque , Nikolai Lehtinen

In this article we present triple differential cross sections for equal energy sharing kinematics for double photoionization of the helium atom at 20 and 40eV above threshold in the framework of the hyperspherical partial wave theory. This…

Atomic Physics · Physics 2009-11-10 J. N. Das , K. Chakrabarti , S. Paul

In this paper, we have investigated the correlated electron emission of the nonsequence double ionization (NSDI) in an intense linearly polarized field. The theoretical model we employed is the semiclassical rescattering model, the model…

Atomic Physics · Physics 2007-05-23 Li-Bin Fu , Jie Liu , Shi-Gang Chen

We examine the fate of fast electrons (with energies E>10 eV) in a thermal gas of primordial composition. To follow their interactions with the background gas, we construct a Monte Carlo model that includes: (1) electron-electron scattering…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Steven Furlanetto , Samuel Johnson Stoever

We report on a kinematically complete measurement of double ionization of helium by a single 1100 eV circularly polarized photon. By exploiting dipole selection rules in the two-electron continuum state, we observed the angular emission…