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Related papers: R-matrix electron-impact excitation data for astro…

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Differential cross sections for electron collisions with the O$_2$ molecule in its ground ${X}^{3}\Sigma_g^-$ state, as well as excited ${a}^{1}\Delta_g$ and ${b}^{1}\Sigma_g^+$ states are calculated. As previously, the fixed-bond R-matrix…

Chemical Physics · Physics 2008-12-18 Motomichi Tashiro , Keiji Morokuma , Jonathan Tennyson

We report calculations of energy levels, radiative rates and electron impact excitation cross sections and rates for transitions in He-like Kr XXXV. The GRASP (general-purpose relativistic atomic structure package) is adopted for…

Atomic Physics · Physics 2015-06-05 K. M. Aggarwal , F. P. Keenan

The Axelrod approximation is widely used in astrophysical modelling codes to evaluate electron-impact excitation effective collision strengths for forbidden transitions. Approximate methods such as this are a necessity for many heavy…

High Energy Astrophysical Phenomena · Physics 2025-09-17 Leo P. Mulholland , Steven J. Bromley , Connor P. Ballance , Stuart A. Sim , Catherine A. Ramsbottom

Calculations are presented which use the molecular R-matrix with pseudo-states (MRMPS) method to treat electron impact electron detachment and electronic excitation of the carbon dimer anion. Resonances are found above the ionisation…

Atomic Physics · Physics 2010-07-07 Gabriela Halmova , J. D. Gorfinkiel , Jonathan Tennyson

Utilising previous work by the authors on the spin-coupled rotational cross-sections for electron-CN collisions, data for the associated rate coefficients is presented. Data on rotational, fine-structure and hyperfine-structure transition…

Chemical Physics · Physics 2015-06-16 Stephen Harrison , Alexandre Faure , Jonathan Tennyson

Rotational excitation of isotopologues of HCN and HNC by thermal electron-impact is studied using the molecular {\bf R}-matrix method combined with the adiabatic-nuclei-rotation (ANR) approximation. Rate coefficients are obtained for…

Astrophysics · Physics 2009-11-13 A. Faure , H. N. Varambhia , T. Stoecklin , J. Tennyson

New calculations of the energy levels, radiative transition rates and collisional excitation rates of \ion{Fe}{ix} have been carried out using the Flexible Atomic Code, paying close attention to experimentally identified levels and…

Solar and Stellar Astrophysics · Physics 2015-05-28 Adam R Foster , Paola Testa

We describe the computer codes, developed at Vilnius University, for the calculation of electron-impact excitation cross sections, collision strengths, and excitation rates in the plane-wave Born approximation. These codes utilize the…

Atomic Physics · Physics 2015-04-08 P. Bogdanovich , R. Kisielius , D. Stonys

We report on the latest measurements of the production of $\Upsilon$ mesons in heavy-ion collisions from the STAR experiment at RHIC. New measurements of the nuclear modification factors of the $\Upsilon$(1S+2S+3S) and $\Upsilon$(1S) states…

High Energy Physics - Experiment · Physics 2019-08-13 Robert Vertesi

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

The spectra from Fe-peak elements may be used to determine the temperature and density of various astrophysical objects. Determination of these quantities is underpinned by the accuracy and the comprehensiveness of the underlying atomic…

Instrumentation and Methods for Astrophysics · Physics 2018-12-19 Luis Fernández-Menchero , Ryan T. Smyth , Catherine A. Ramsbottom , Connor P. Ballance

Spectral modelling of kilonovae (KNe) require large amounts of collisional excitation and photoionization atomic data for lowly ionised (neutral, singly and doubly ionised) species of heavy elements. Much of the data currently used is…

High Energy Astrophysical Phenomena · Physics 2026-02-25 Leo P. Mulholland , Catherine A. Ramsbottom , Connor P. Ballance , Albert Sneppen , Stuart A. Sim

In this work, we investigate the ionization of silicon by electron impacts in hot plasmas. Our calculations of the cross sections and rates rely on the Coulomb-Born-Exchange, Binary-Encounter-Dipole and Distorted-Wave methods implemented in…

Atomic Physics · Physics 2024-12-10 Jean-Christophe Pain , Djamel Benredjem

$R$-matrix calculations of the electron collisions with lithium atom at energies below the $3s$ excitation threshold are presented. The $^1S^e$, $^3S^e$ and $^1P^o$ phase shifts calculated in the near-threshold energy range are in excellent…

Atomic Physics · Physics 2019-01-23 Michal Tarana , Roman Čurík

This work reports radiative transition rates and electron impact excitation rate coefficients for levels of the n= 3, 4, 5, 6, 7, 8 configurations of Ca II. The radiative data were computed using the Thomas-Fermi-Dirac central potential…

Astrophysics · Physics 2009-11-13 M. Melendez , M. A. Bautista , N. R. Badnell

A comprehensive study of relativistic and resonance effects in electron impact excitation of (e+Fe XVII) is carried out using the BPRM method in the relativistic close coupling approximation. Two sets of eigenfunction expansions are…

Astrophysics · Physics 2009-11-07 Guo-Xin Chen , Anil K. Pradhan , W. Eissner

Phosphorus abundance is crucial for DNA-based extraterrestrial life in exoplanets. Atomic data for observed spectral lines of P-ions are needed for its accurate determination. We present the first calculations for collision strengths for…

Solar and Stellar Astrophysics · Physics 2018-06-13 Rahla Naghma , Sultana N. Nahar , Anil K. Pradhan

Collisions of heavy ions (nuclei) at ultra-relativistic energies (sqrt(s_NN) >> 10 GeV per nucleon-nucleon collision in the centre of mass system) are regarded as a unique tool to produce in the laboratory a high energy density and high…

High Energy Physics - Phenomenology · Physics 2010-12-21 A. Dainese

R-matrix with time-dependence theory is applied to electron-impact ionisation processes for He in the S-wave model. Cross sections for electron-impact excitation, ionisation and ionisation with excitation for impact energies between 25 and…

Atomic Physics · Physics 2016-09-21 Jack Wragg , Hugo W. van der Hart

Laser pulses with a duration of the order of femtoseconds lead to a strong excitation, heating and potentially to ablation of the irradiated material. During the time of strong excitation, the interaction of the atoms and thus the material…

Materials Science · Physics 2025-07-01 Simon Kümmel , Johannes Roth