Electric quadrupole transition probabilities for atomic lithium

Electric quadrupole transition probabilities for atomic lithium have been calculated using the weakest bound electron potential model theory (WBEPMT). We have employed numerical non-relativistic Hartree–Fock wavefunctions for expectation values of radii and the necessary energy values have been taken from the compilation at NIST. The results obtained with the present method agree very well with the Coulomb approximation results given by Caves (1975). Moreover, electric quadrupole transition probability values not existing in the literature for some highly excited levels have been obtained using the WBEPMT.     

Electric quadrupole transition probabilities and line strengths of Ti

Electric quadrupole transition probabilities and line strengths have been calculated using the weakest bound electron potential model for sodium-like titanium, considering many transition arrays. We employed numerical Coulomb approximation and non-relativistic Hartree–Fock wavefunctions for the expectation values of radii in determination of parameters of the model. The necessary energy values have been taken from experimental data in the literature. The calculated electric quadrupole line strengths have been compared with available data in the literature and good agreement has been obtained. Moreover, some electric quadrupole transition probability and line strength values not existing in the literature for some highly excited levels have been obtained using this method.     

Electric dipole,quadrupole, and magnetic dipole transition probabilities of ions isoelectronic to the first-row atoms,Li through F

Theoretical wavelengths, oscillator strengths, line strengths, and transition probabilities for the E1, M1, and E2 transitions among states with 2sⁿ2p^m configurations are presented for ions isoelectronic to the first-row atoms (Li through F). All ions up to Zn (Z = 30) and representative ions for Z > 30 are included. The multiconfiguration Dirac-Fock technique was used to calculate necessary energy levels and wave functions. All configurations within the n = 2 complex are included to account for electron correlations and intermediate coupling. In addition to relativistic effects arising from the Dirac Hamiltonian and the Breit operator, we included the Lamb shifts of the $\text{1s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, $\text{2s}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, and $\text{2p}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ electrons.     

Electric-dipole transition probabilities of Al-like ions

Theoretical wavelengths, oscillator strengths, and transition probabilities for the E1-transitions between levels of the ground complex (n = 3)³ of the Al-like ions are presented. Calculations are made for 27 ions of the Al-sequence up to Z = 93. The Relativistic Parametric Potential Method was used to calculate energy levels and wave functions. All configuration interactions within the ground complex are included to account for electron correlations and intermediate coupling. Relativistic effects are taken into account by means of the Coulomb-Dirac Hamiltonian. The Breit term and the Lamb shift are neglected.     

Franck-Condon factors, transition probabilities, and radiative lifetimes for hydrogen molecules and their isotopomeres

A systematic fundamental molecular database for all isotopomeres of the hydrogen molecule (H₂, D₂, T₂, HD, HT, DT) is calculated on the basis of the latest Born-Oppenheimer potential curves and the latest electronic dipole transition moments of hydrogen molecules. Vibrational eigenvalues, Franck-Condon factors, and vibrationally resolved transition probabilities are presented for electronic transitions in each multiplet system up to principal quantum number n = 4. Radiative lifetimes of the vibrational levels in the electronically excited states are obtained from the summation over the optically allowed transitions. In a similar manner, effective transition probabilities and effective radiative lifetimes of electronically excited states are determined assuming that only the lowest vibrational level in the ground state is populated, i.e. the data are directly applicable to molecular gases. Differences between the isotopomeres are discussed briefly.     

Collisional transition probabilities for atomic hydrogen in thermal plasmas from 1000°K to 8000°K

Results are presented of calculations of the transition probabilities induced by electron-hydrogen atom collisions described with the aid of the classical binary encounter theory. The electrons are assumed to be Maxwellian. The range of temperatures covered is from 1000°K to 8000°K.     

Energy-level scheme and transition probabilities of Si-like ions

Theoretical energy levels and transition probabilities are presented for 27 low-lying levels of silicon-like ions from Z = 15 to Z = 106. The multiconfiguration Dirac-Fock technique is used to calculate energy levels and wave functions. The Breit interaction and Lamb shift contributions are calculated perturbatively as corrections to the Dirac-Fock energy. The M1 and E2 transitions between the five levels of the ground-state configuration and the E1 transitions between excited and the ground levels are presented.     

Energy-level scheme and transition probabilities of P-like ions

Theoretical energy levels and transition probabilities are presented for 41 low-lying levels of phosphorus-like ions. The multiconfiguration Dirac-Fock technique is used to calculate energy levels and wave functions. The Breit interaction and Lamb shift contributions are calculated perturbatively as corrections to the Dirac-Fock energy. The M1 and E2 transitions between the five levels of the ground-state configuration and the E1 transitions between excited and ground levels are presented.     

Energy-level scheme and transition probabilities of Cl-like ions

Theoretical energy levels and transition probabilities are presented for 31 low-lying levels of chlorine-like ions. The multiconfiguration Dirac-Fock technique is used to calculate energy levels and wave functions. The Breit interaction and Lamb shift contributions are calculated perturbatively as corrections to the Dirac-Fock energy. The E1 transitions between excited and ground levels and the M1 and E2 transitions between the two levels of the ground-state configuration are presented.     

Oscillator strengths and transition probabilities of O II

The abundance of singly ionized oxygen, O II, in planetary nebulae provides crucial diagnostic tests for the physical conditions present in these astrophysical environments. The abundance can be determined from the absorption lines formed by the radiative processes, such as the photo-excitations reported here. Radiative transitions are obtained from a total of 708 fine structure levels of O II with , and 1/2?J?17/2. For spectral analysis oscillator strengths, line strengths, and transition probabilities (A) are presented for 51,733 electric dipole fine structure radiative transitions. The calculations were carried out in the relativistic Breit-Pauli R-matrix approximation. The transitions have been identified spectroscopically using quantum defect analysis and other criteria. The calculated energies agree with the observed energies within 5% for most of the levels. However, some relatively large differences are noted, the largest difference being 13% for the level 2s²2p²(¹D)4p(²F^o)_7/2. Most of the A values and lifetimes agree with the existing measured and calculated values. The transitions should be applicable for diagnostics as well as spectral modeling in the ultraviolet and optical regions of astrophysical and laboratory plasmas.     

The energy levels and radiative transition probabilities for electric quadrupole and magnetic dipole transitions among the levels of the ground configuration, [Kr]4d4f, of W

Large-scale multiconfiguration Hartree-Fock and Dirac-Fock calculations have been performed for the ground configuration, [Kr]4d¹⁰4f⁴, energy levels of the W²⁴⁺ ion. The relativistic corrections were taken into account in the quasirelativistic Breit-Pauli and fully relativistic Breit (taking into account QED effects) approximations. The role of correlation, relativistic, and QED corrections is discussed. Line strengths, oscillator strengths, and transition probabilities in the Coulomb and Babushkin gauges are presented for the electric quadrupole (E2) transitions among these levels. The magnetic dipole transitions are also investigated. Dependence of the E2 transition probabilities on the gauge condition of the electromagnetic field potential is studied as well.     

Energy levels,wavelengths, and transition probabilities of Cu-like ions

Wavelengths, oscillator strengths, and transition probabilities for the electric dipole transitions between low-lying states (n = 4, 5, 6) of Cu-like ions are presented. The data are calculated from relativistic Hartree-Fock wavefunctions.     

The effect of MeV ion irradiation on the hydrogen content and resistivity of direct ion beam deposited diamondlike carbon

Diamondlike carbon films fabricated by direct ion beam deposition have been irradiated with 6.4 MeV fluorine and 1 MeV gold ions. Both beams reduce the hydrogen content with the fluorine beam being much more efficient than the gold beam. The resistivity of the materials is also reduced by both beams with the fluorine beam producing a much larger drop in resistivity and a lower fluence than the gold beam. It is concluded that defects produced by electronic energy loss of the bombarding ions are responsible for both the loss of hydrogen and the change in resistivity. The magnitude of both of these effects is reduced with increasing ion mass as the proportion of nuclear to electronic energy loss is increased. This is due to the production of retrapping centers in the case of hydrogen and ion induced annealing in the case of resistivity. There is a threshold in fluence for both effects and this may be associated with fluctuations in the rate of deposition of the electronic energy loss along an individual ion track.     

The production of non linear damage under molecular ion implantation

Germanium atomic (Ge₁) and molecular ions (Ge₂) of equivalent energy are implanted in silicon at an elevated temperature. The ion induced damage has been characterized by RBS channeling (RBS/C) and positron annihilation spectroscopy. The RBS/C studies indicate that the molecular ion implantation has produced more defects in the near surface regions compared to the atomic ion implantation. This paper reports a first time observation of an enhanced production of vacancy related defects in silicon implanted with molecular ions.     

The study of reduced transition probabilities for E2 transitions in the decays of Os and Pt nuclei

The ratios of E2 transition rates, i.e., B(E2; I_i − I_f)/B(E2; I_i − I_f) were computed for gamma to ground state band transitions in ¹⁹²Os and ¹⁹²Pt. The reduced transition probabilities for the E2 transitions evaluated on the basis of Interacting Boson Approximation (IBA-I) model and those measured experimentally are compared. The SU(3) symmetry of IBA-I is not strictly obeyed by the nuclei in which T(E2; I_i − I_f) transitions are observed, i.e., the symmetry SU(3) is broken. The percentage sum coincidence corrections are applied to marginalise contributions from crossover transitions and the intensities of affected transitions are found to agree fairly well with earlier sum peak method applications to the decay of ¹⁹²Ir.     

Energy levels,lifetimes, wavelengths,and transition probabilities of Fe XIV

Energy levels and lifetimes are reported for all the states of the n = 3 odd and even complexes of Fe XIV, as well as the 2s²4l²L states. Data for selected allowed (E1) and forbidden (E2, M1, and M2) transitions between these states are also reported. The results have been calculated using the multiconfiguration Hartree-Fock method with a Breit-Pauli relativistic correction.     

Relativistic energy levels, lifetimes, and transition probabilities for the sodium-like to argon-like sequences

Energy levels, lifetimes, and transition probabilities for transitions between computed levels are reported for the Na-like (Z = 11, … , 26) to Ar-like (Z = 18, … , 30) sequences. Several methods have been used—non-orthogonal spline CI, multiconfiguration Hartree-Fock (MCHF), and also multiconfiguration Dirac-Hartree-Fock (MCDHF). The first two methods included relativistic effects through the Breit-Pauli Hamiltonian, omitting only the orbit-orbit interaction. Both allowed (E1) and some forbidden (M1, E2, M2, E3) transitions are reported.     

Relativistic MR-MP calculations of the energy levels and transition probabilities in Ni- to Kr-like Pt ions

Ni- to Kr-like Pt ions have been studied by relativistic multi-reference Møller–Plesset many-body perturbation theory calculations. Energy levels and lifetimes of low-lying excited states within the n=4$n=4$ complex are reported for each ion. Wavelengths and transition probabilities for the strongest electric-dipole transitions are compared with available experimental data. Synthetic radiative spectra are shown for various wavelength regions.