We review the development of time-dependent close-coupling method to study atomic and molecular few body dynamics. Applications include electron photon collisions with atoms, molecules, their ions.

Differential and integral cross sections are calculated in the centre of mass energy range 0.1-100 eV for elastic scattering protons (H+, D+, T+) by helium symmetric combinations hydrogen atoms (H, D, T) T). In addition, we derive from differential momentum transfer viscosity use study plasma transport, compute charge section. Fully quantal semiclassical approaches utilized these calculations, as very accurate electronic potential curves. The results compared with available data.

We study the behavior of ionization in intermediate-energy collisions antiprotons with atomic hydrogen by direct solution time-dependent Schr\"odinger equation represented on a three-dimensional Cartesian lattice. Total cross sections for these processes are computed over collision energy range 0.2 to 500 keV from knowledge asymptotic state probabilities as function impact parameter. The good agreement results recent experiments conducted at CERN [Phys. Rev. Lett. 74, 4627 (1995)]. In 30...

Electron-impact ionization of atomic hydrogen is studied by direct solution a set time-dependent close-coupled partial differential equations. The equations describe the propagation time-evolving wave packet on two-dimensional radial lattice. Following collision, projected onto stationary states target to obtain probabilities for elastic and inelastic scattering processes. Ionization cross sections are calculated various LS waves compared with previous theoretical methods. \textcopyright{}...

Total cross sections for single ionization and charge transfer have been calculated using the classical-trajectory Monte Carlo (CTMC) technique collisions of both positrons protons with helium. Analysis classical trajectories has helped to explain differences in collision mechanisms responsible observed relative magnitudes positron proton electron-removal sections. In intermediate velocity range (1.5 a.u.<v<4.5 a.u.) it is found that because much smaller mass than proton, two dynamical...

Owing to the crucial role played by elastic scattering in various gas/plasma environments and its fundamental nature, we consider present work low-energy collisions among isotopic variants of ${\mathrm{H}}^{+}+\mathrm{H}, \mathrm{H}+\mathrm{H},$ ${\mathrm{H}}^{+}+{\mathrm{H}}_{2}.$ In particular, consistent definitions elastic-scattering cross section common transport relevant moments regarding quantum indistinguishability or classical distinguishability particles, correcting some...

Presented here is a description of the ionization hydrogen and hydrogenic ions by antiproton impact, based on very large scale numerical solutions time-dependent Schr\"odinger equation in three spatial dimensions analysis topology electronic eigenenergy surfaces plane complex internuclear distance. Comparison made with other theories recent measurements.

We present and compare total cross sections for single-electron removal in collisions of electrons, positrons, protons, antiprotons with atomic hydrogen helium. These have been calculated using the classical trajectory Monte Carlo technique velocity range 0.5--7.0 a.u. (6.25--1224 keV/u). The are compared at equal collision velocities exhibit differences arising from variations mass sign charge projectile. At low intermediate these large both ionization transfer channels. high...

An impulse approximation for ionizing collisions of clothed ions with atoms is used to explain the origin an anomalous oscillation in ejected electron spectrum region binary peak. In addition, measurements which evidence this feature 1-MeV/u ${\mathrm{U}}^{21+}$ colliding helium are presented. It shown that behavior arises from interference structures elastic differential cross section scattering target electrons impinging ion and it associated well-known phenomenon rainbow scattering.

The relatively recent advent of low energy antimatter projectiles has spurred a rapid advance in the comparison matter- and antimatter-atom collisions. These experimental studies have turn stimulated great deal theoretical effort to explain their results, together both theory experiment shed new light on dynamics ion-atom authors review these developments with particular emphasis processes ionization charge transfer.

Auroral X‐ray emissions from Jupiter with a total power of about 1 GW have been observed by the Einstein Observatory, Roentgen satellite, Chandra and XMM‐Newton. Previous theoretical studies shown that precipitating energetic sulfur oxygen ions can produce X‐rays. This study presents results hybrid Monte Carlo (MC) model for ion precipitation at high latitudes, looks differences continuous slow‐down model, compares to synthetic spectra fitted observations. We concentrate on effects altitude...

We present measurements and calculations of the momentum distribution electrons emitted during ion-atom collision 10 keV/u $He^{2+}+He \rightarrow He^{+} + He^{2+} e^{-}$, which show rich structures for ion scattering angles above 2 mrad arising dominantly from two-electron states. Our reveal that minima in measured distributions are zeros electronic probability density resulting vortices current.

Excitation and charge transfer cross sections for collisions of protons with hydrogen are calculated by direct solution the time-dependent Schr\"odinger equation on a three-dimensional Cartesian lattice. The $2s,$ $2p,$ $3s,$ $3p,$ $3d$ excitation $1s,$ from $1s$ ground state at 10-, 40-, 100-keV incident proton energy found projecting time-evolved wave function onto lattice target states hydrogen. processes in rest frame atom, while capture proton. computed good agreement recent experiments...

Results of crossed-beam measurements cross sections differential in ejected electron energy and angle for ionization atomic hydrogen by 20--114-keV protons are reported. Secondary electrons were measured over an range 1.5--300 eV angular 15\ifmmode^\circ\else\textdegree\fi{}--165\ifmmode^\circ\else\textdegree\fi{}. Atomic-hydrogen targets produced a radio-frequency discharge source with dissociation fraction about 74%. Ratios H to those ${\mathrm{H}}_{2}$ obtained from on the mixed target....

Utilizing a lattice representation of the wave function and operators, we have solved time-dependent Schr\"odinger equation over wide range collision energies impact parameters to study excitation low-lying states in collisions protons with atomic hydrogen. The technique circumvents many shortcomings commonly applied close coupling perturbation theory approaches that are valid only restricted regimes. Thus, investigation represents step towards precise knowledge dynamical quantities...

We present quantum mechanical close-coupling calculations of collisions between two hydrogen molecules over a wide range energies, extending from the ultracold limit to superthermal region. The most recently published potential energy surfaces for H(2)-H(2) complex, so-called Diep-Johnson (DJ) [J. Chem. Phys. 112, 4465 (2000); 113, 3480 (2000)] and Boothroyd-Martin-Keogh-Peterson (BMKP) 116, 666 (2002)] surfaces, are quantitatively evaluated compared through investigation rotational...

The momentum transfer and viscosity cross sections for proton-hydrogen collisions are computed in the velocity range of ~200-20,000 km s−1 relevant to a wide astrophysical environments such as supernova remnant shocks, solar wind, winds within young stellar objects or accretion disks, interstellar protons interacting with heliosphere. A variety theoretical approaches used arrive at best estimate these this that smoothly connect very accurate results previously lower velocities. Contributions...

Spectra of Jovian X‐ray auroras observed from the North and South poles with Chandra telescope are analyzed compared predicted spectra charge‐exchange mechanism. To determine theoretical auroras, we model numerically collisionally induced evolution energy charge distributions O q + S ions, precipitating into atmosphere. Monte Carlo simulations relaxation ions carried out updated cross‐sections ion stripping, electron capture, gas‐ionization collisions. Extreme Ultraviolet (EUV) cascading...

Vortices are usually associated with systems containing large numbers of particles. Of particular topical interest though those formed within atomic-scale wave functions and observed in macroscopic such as superfluids quantum condensates. We uncover them here one the most fundamental consisting just electron two protons. Moreover, results novel simulations dynamics this system reveal previously unknown mechanisms angular momentum transfer new ways to image quantized vortices at distances....

The spatially localized and highly variable polar cap emissions at Jupiter are part of a poorly understood current system linking the ionosphere magnetopause region. Strong X‐ray emission has been observed from caps explained by precipitation oxygen sulfur ions several MeV energy. present paper presents results an extended model ion process Jupiter. Specifically, we add to previous more complete treatment ionization atmosphere, generation secondary electron fluxes their escape downward...

Abstract The fundamental collisional process of charge exchange (CX) has been established as a primary source X-ray emission from the heliosphere, planetary exospheres, and supernova remnants. In this process, results capture an electron by highly charged ion neutral atom or molecule, to form excited, high-charge state ion. As captured cascades down lowest energy level, photons are emitted, including X-rays. To provide reliable CX-induced spectral models realistically simulate these...

We report new and highly accurate quantum mechanical calculations of the astrophysically interesting scattering H+ by H atoms. The effects indistinguishability two protons are treated consistently throughout, including calculation momentum transfer cross section where elastic charge cannot be separated at low energies. able to resolve numerous oscillations in energy variation angle-integrated sections. With decreasing below 1 eV, grow amplitude until a smooth, approximately 1/v2 dependence...

The impulse or binary encounter approximation for ion-atom collisions is extended to treat the non-Coulomb interaction between a clothed projectile ion and target electrons. This model shown reproduce unexplained enhancement of zero-degree peak partially stripped ions over that equivelocity fully has recently been observed experimentally in Fq++H2, He collisions. Very good agreement obtained theory experiment and, furthermore, this used illuminate underlying dynamics which leads enhancement.