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.     

Cross-sections and transport properties of F ions in Ar, Kr and Xe

The aim of the current work is to determine with relatively high accuracy the elastic momentum-transfer cross-sections of F⁻ ions in collisions with noble gases Ar, Kr and Xe. We have applied a simple form of momentum-transfer theory (MTT) based on elastic collisions as the first step in order to develop negative fluorine ion/Ar, Kr, Xe elastic momentum-transfer cross-sections based on the available data for reduced mobilities at 300 K as a function of E/N. In our procedure MTT is used only as the initial step to make adjustments and thus save a lot of computation time. However, our final results have been all obtained by exact Monte Carlo (MC) technique that has been well tested and documented. The unfolded cross-sections were validated or further improved by assuring a good agreement between our MC calculated transport data and the available experimental results for reduced mobility and longitudinal diffusion in the range from 1 Td to 500 Td. We have also calculated the net rates of elastic scattering and detachment.     

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.     

Energy levels, transition probabilities, and electron impact excitation collision strengths for Xe XXVII

The energy levels, spontaneous radiative decay rates, and electron impact collision strengths are calculated for Xe XXVII. The data refer to 107 fine-structure levels belonging to the configurations (1s²2s²2p⁶)3s²3p⁶3d¹⁰, 3s²3p⁶3d⁹4l, 3s²3p⁵3d¹⁰4l and 3s3p⁶3d¹⁰4l (l = s, p, d, f). The collision strengths are calculated with a grid of 20 collision energies between 10 and 1500 eV in terms of the energy of the scattered electron, by using the distorted-wave approximation. Effective collision strengths are obtained at six temperatures, T_e (eV) = 10, 100, 300, 500, 800 and 1500, by integrating the collision strengths over a Maxwellian electron distribution. Coupled with these atomic data, a hydrodynamic code MED103 can be used to simulate the Ni-like Xe X-ray laser.     

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.     

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.     

Wavelengths and transition probabilities in heavy Ge-like ions (70 ? Z ? 92)

Wavelengths and transition probabilities have been calculated for the 4s²4p²-4s4p³ and 4s²4p²-4s²4p4d allowed transitions and for the forbidden (M1 and E2) transitions occurring within the ground configuration (4s²4p²) in the heavy Ge-like ions with Z = 70-92. The fully relativistic multiconfiguration Dirac-Fock method taking into account both the correlations within the n = 4 complex and the QED effects has been used for the calculations. The present results are compared to and agree well with recent electron-beam ion-trap measurements in tungsten, osmium, gold, bismuth, thorium, and uranium.     

用制备色谱法分离氪氙

叙述了通过改变填充5A分子筛色谱柱的载气流速和色谱柱温度,改变氪、氙的保留时间,实现氪、氙分离。分离后,在低温下分别用活性炭收集。结果表明,延长氪、氙色谱柱保留时间的间隔,可提高氪、氙的去污系数;在–80oC低温下,活性炭能很好地收集氪和氙,回收率>95%。     

Color center creation in LiF crystals irradiated with Xe, Kr and N ions: Dependence on fluence and beam current density

Single LiF crystals were irradiated with Xe (195 MeV), Kr (117 MeV), and N (18 MeV) ions. Using absorption spectroscopy, color center creation was analyzed as a function of the ion energy loss, fluence, and flux. The concentration of single F centers and F₂ centers versus fluence and flux exhibits a nonlinear evolution with saturation at higher fluences. For LiF irradiated with N ions at high fluence, the concentration of F centers is proportional to the cube root of the flux indicating the strong interaction of primary hole centers. Macroscopic hillocks were observed in all irradiated LiF crystals by atomic force microscopy.     

Fine-structure calculations of energy levels, oscillator strengths, and transition probabilities for sodium-like ions (Co XVII-Kr XXVI)

We have calculated fine-structure energy levels, oscillator strengths and transition probabilities for transitions among the terms belonging to the 1s²2s²2p⁶ns (²S), 1s²2s²2p⁶np (²P), 1s²2s²2p⁶nd (²D) (n = 3, 4, 5), and 1s²2s²2p⁶nf (²F) (n = 4, 5) configurations. The calculations are based upon the general configuration-interaction code CIV3 of Hibbert which uses orthonormal orbitals of radial functions expressed as superpositions of normalized Slater-type orbitals. Our calculated values are compared with experimental and other theoretical results where a satisfactory agreement is found. We also report on some unpublished energy values and oscillator strengths.     

Effects of energy deposition on mechanical properties of sodium borosilicate glass irradiated by three heavy ions: P,Kr, and Xe

Sodium borosilicate glasses are candidate materials for high-level radioactive waste vitrification;therefore, understanding the irradiation effects in model borosilicate glass is crucial. Effects of electronic energy deposition and nuclear energy deposition induced by the impact of heavy ions on the hardness and Young's modulus of sodium borosilicate glass were investigated. The work concentrates on sodium borosilicate glasses, henceforth termed NBS1(60.0% SiO_2, 15.0% B_2O_3, and 25.0% Na_2O in mol%). The NBS1 glasses were irradiated by P, Kr, and Xe ions with 0.3 MeV, 4 MeV, and 5 MeV, respectively.The hardness and Young's modulus of ion-irradiated NBS1 glasses were measured by nanoindentation tests. The relationships between the evolution of the hardness, the change in the Young's modulus of the NBS1 glasses, and the energy deposition were investigated. With the increase in the nuclear energy deposition, both the hardness and Young's modulus of NBS1 glasses dropped exponentially and then saturated. Regardless of the ion species, the nuclear energy depositions required for the saturation of hardness and Young's modulus were apparent at approximately 1.2 × 10~(20) keV/cm~3 and 1.8 × 10~(20) keV/cm~3,respectively. The dose dependency of the hardness and Young's modulus of NBS1 glasses was consistent with previous studies by Peuget et al. Moreover, the electronic energy loss is less than 4 keV/nm, and the electronic energy deposition is less than 3.0 × 10~(22) keV/cm~3 in this work. Therefore, the evolution of hardness and Young's modulus could have been primarily induced by nuclear energy deposition.     

Atomic data and theoretical X-ray spectra of Ge-like through V-like W ions

The atomic structure and spectra of ten tungsten ions have been calculated using the Flexible Atomic Code. The calculations yield energy levels, radiative lifetimes, spectral line positions, transition probability rates, and oscillator strengths for the tungsten ions isoelectronic to germanium, W⁴²⁺${}^{42+}$, through vanadium, W⁵¹⁺${}^{51+}$. Collisional–radiative models for high-temperature, low-density plasmas have been implemented to produce line emissivities for X-ray transitions in the 1–4 keV (3–12 Å) spectral interval. The Ge-like through V-like W ions are important in nuclear fusion research where their spectra may provide diagnostic information on magnetically confined plasmas.     

Wavelengths and transition probabilities of satellites to resonance lines of H- and He-like ions

The wavelengths, radiative transition probabilities, and autoionization rates have been calculated for ions with atomic numbers Z = 4 to 34. Transitions 2p-1s, 2p2l-1s2l, 1s2l-1s², 1s2p2l-1s²2l have been considered. Perturbation theory in $\text{1}\text{Z}$ has been used.     

燃料棒芯块中Kr、Xe的低温释放机理

在Wise反冲机理微观模型的基础上,考虑芯块倒角的影响,给出了倒角表面平均反冲效率的计算模型;击出机理参考Olander的理论;由此建立了一个更为精细的裂变气体低温释放微观模型.使用新建模型进行计算的结果显示,倒角表面的平均反冲效率约为圆柱体芯块表面的两倍;当倒角的表面积与圆柱体芯块表面积相比不可忽略时,裂变气体反冲释放份额的计算应考虑倒角的影响.     

Electric-dipole,quadrupole, and magnetic-dipole susceptibilities and shielding factors for closed-shell ions of the He,Ne, Ar,Ni (Cu+), Kr,Pb, and Xe isoelectronic sequences

Theoretical values of electric and magnetic susceptibilities (α₁, α₂, χ₁) and shielding factors (γ₁, γ₂, σ₁) calculated in the relativistic random-phase approximation are presented in tabular form for ions with closed 1s, 2p, 3p, 3d, 4p, 4d, and 5p shells. The table includes all ions in these sequences with nuclear charge up to Z = 56 and a representative selection of ions with 56 < Z ? 92.     

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.     

Energy levels, transition probabilities, and electron impact excitations for La XXX

The energy levels, spontaneous radiative decay rates, and electron impact collision strengths are calculated for La XXX. The data refer to 107 fine-structure levels belonging to the configurations (1s²2s²2p⁶)3s²3p⁶3d¹⁰, 3s²3p⁶3d⁹4l, 3s²3p⁵3d¹⁰4l, and 3s3p⁶3d¹⁰4l (l = s, p, d, f). The collision strengths are calculated with a 20-collision-energy grid in terms of the energy of the scattered electron between 10 and 10,000 eV by using the distorted-wave approximation. Effective collision strengths are obtained at seven electron temperatures: T_e (eV) = 10, 100, 300, 500, 800, 1000, and 1500 by integrating the collision strengths over a Maxwellian electron distribution. Coupled with these atomic data, a hydrodynamic code MED103 can be used to simulate the Ni-like La X-ray laser at 8.8 nm.