相关论文: R-matrix calculation of electron collisions with e…
There are major discrepancies between recent B-spline R-matrix (BSR) and Dirac Atomic R-matrix Code (DARC) calculations regarding electron-impact excitation rates for transitions in Mg$^{4+}$, with claims that the DARC calculations are much…
We measure the energy-differential cross sections for collisional excitation of the soft X-ray electric-dipole K$\alpha$ ($x+y+w$) emission from He-like oxygen (O VII), using an electron beam ion trap. Values near their excitation…
The R-matrix method has been used for theoretical calculation of electron collision with atoms and molecules for long years. The method was also formulated to treat photoionization process, however, its application has been mostly limited…
Techniques for producing cold and ultracold molecules are enabling the study of chemical reactions and scattering at the quantum scattering limit, with only a few partial waves contributing to the incident channel, leading to the…
Cold, neutral hydroxyl radicals are Stark decelerated and confined within a magnetic trap consisting of two permanent ring magnets. The OH molecules are trapped in the ro-vibrational ground state at a density of $\sim10^{6}$ cm$^{-3}$ and…
The bound and resonance states along with corresponding autoionization widths for nitrogen sulphide (NS) molecule are determined using electron NS$^+$ cation scattering calculations. The calculations are performed for $^2{\Sigma}^+$,…
Spectral lines from N-like ions can be used to measure the temperature and density of various types of astrophysical plasmas. The atomic databases of astrophysical plasma modelling codes still have room for improvement in their…
We present measurements of the total projectile-electron-loss cross sections in O$^-$ + N$_2$ collisions in the energy range from 2.5 to 8.5 keV. Two different techniques, beam attenuation and the growth rate, are employed. The difference…
The primary X-ray diagnostic lines in He-like ions are mainly excited by electron impact from the ground level to the n = 2 levels, but at high temperatures n > 2 levels are also excited. In order to describe the atomic processes more…
We present electron collision strengths and their thermally averaged values for the forbidden lines of the astronomically abundant doubly-ionized oxygen ion, O^{2+}, in an intermediate coupling scheme using the Breit-Pauli relativistic…
Rotational transitions in molecular hydrogen collisions are computed. The two most recently developed potential energy surfaces for the H2-H2 system are used from the following works: 1) A.I. Boothroyd, P.G. Martin, W.J. Keogh, M.J.…
We provide cross sections and Maxwell rate coefficients for reactive collisions of slow electrons with BeH$^+$ ions on all the eighteen vibrational levels ($X{^{1}\Sigma^{+}},v_{i}^{+}=0,1,2,\dots,17$) using a Multichannel Quantum Defect…
We present an experimental study of the dissociative excitation in the collision of helium ions with nitrogen and oxygen molecules for collision energy of $0.7-10$ keV. Absolute emission cross sections are measured and reported for most…
There are major discrepancies between recent ICFT (Intermediate Coupling Frame Transformation) and DARC (Dirac Atomic R-matrix Code) calculations (Fern\'andez-Menchero et al. 2014, Astron. Astroph. 566 A104, Aggarwal et al. 2016 Mon. Not. R…
Analytical formulas for the excitation energies as well as for the electric quadrupole reduced transition probabilities in the ground, beta and gamma bands were derived within the coherent state model for the near vibrational and well…
The H$_2$+H$_2$ system has long been considered as a benchmark system for ro-vibrational energy transfer in bimolecular collisions. However, most studies thus far have focused on collisions involving H$_2$ molecules in the ground…
Excited atomic nitrogen atoms play an important role in plasma formation in hypersonic shock-waves, as happens during spacecraft reentry and other high velocity vehicle applications. In this study, we have thoroughly studied collision…
We present precision measurements with MHz uncertainty of the energy gap between asymptotic and well bound levels in the electronic ground state X $^1\Sigma_{\mathrm{g}}^+$ of the $^{39}$K$_2$ molecule. The molecules are prepared in a…
The availability of collisional rate coefficients with H$_2$ is a pre-requisite for interpretation of observations of molecules whose energy levels are populated under non local thermodynamical equilibrium conditions. In the current study,…
Cross sections for the rotational (de)excitation of CO by ground state para- and ortho-H_2 are obtained using quantum scattering calculations for collision energies between 1 and 520 cm^{-1}. A new CO-H_2 potential energy surface is…