Fujia Yang

Electron—ion collisional ionization cross sections for the H and He isoelectronic sequences

Abstract In this work, we calculate the electron impact ionization cross sections for H-like and He-like isoelectronic-sequence ions by means of a distorted-wave Born exchange approximation method including a relativistic correction. A computer program has been developed and used to calculate these cross sections. Systematic study of the dependence of the cross sections on impact energies and nuclear charges is carried out. The results of calculations are fitted by empirical formulas to meet the requirements of applications. The fitted values are in good agreement with the calculated results.

Measurement of hyperfine structure in the lines 578.77 nm and 587.04 nm of PrII

The hyperfine structure of the transitions 4f3(4Io)5d 3I5o–4f3(4Io)6p 5I5 (578.77 nm) and 4f3(4Io)5d 3I6o–4f3(4Io)6p? (J=5) (587.04 nm) of 141PrII has been measured by collinear laser‐ion‐beams spectroscopy. The magnetic‐dipole constant A and the electric‐quadrupole constant B of the involved levels have been determined.

RATE COEFFICIENTS OF ELECTRON IMPACT IONIZATION FOR HIGHLY IONIZED IONS

Abstract In this work, some fitting formulas for the accurate and fast calculation of rate coefficient are given. Some fitting parameters of direct ionization cross sections and excitation autoionization cross section are also provided. The rate coefficients of some H-like, He-like and Li-like ions are calculated.

Calculation Of Charge Exchange In Potassium Ions/Atoms Scattered From Metal Surfaces

The charge-exchange processes of K ions/atoms scattered from metal surface are discussed in terms of the time-dependent Newns-Anderson quantum model with intra-atomic Coulomb interaction. The final charge-states distribution is calculated as a function of work function of the surfaces. The calculated results are compared with the experimental data. Furthermore, the probabilities of charge states of the moving K ions/atoms approaching to and leaving from the surface are demonstrated.

Calculation of charge-exchange in lithium ions/atoms scattered from cesiated metal surfaces

Abstract The charge states of Li ions/atoms scattered from a Cs/W(110) surface have been calculated as a function of work function and the temperature of surface in terms of the time-dependent Newns-Anderson quantum model with the intra-atomic Coulomb interaction. The calculated results are in good agreement with the experimental data. Furthermore, the probabilities of charge states of the moving Li ions/atoms approaching to and leaving from the surface are demonstrated.

Isotope Shifts in Nd II by Collinear Fast-Ion-Beam Laser Spectroscopy

Atomic spectra of singly ionized neodymium have been measured by collinear fast-ion-beam laser spectroscopy. The resonant spectra in the lines of 568.9, 570.8, 572.7, and 574.1 nm in Nd II were obtained and the optical shifts were determined. We obtained the optical shifts of all the five even isotopes (142-150) in Nd II. The accuracy of our results was improved by one order of magnitude compared with other published results.

Systematic study on ionization cross sections of electron - ion collisions for the Li-like isoelectronic sequence

In this work, we calculated the ionization cross sections of electron impact for the Li-like isoelectronic sequence. The excitation autoionization is also included in the calculation. The results of the calculations are fitted by empirical formulae to meet the requirements of the applications. The fitted results are in good agreement with the calculated results.

Hyperfine Structure Measurements of NdII Using the Collinear Laser-Ion-Beams Spectroscopy

The hyperfine structures of the transitions 4f 4 ( 5 I)5d 6 G 3/2 →4f 4 ( 5 I)6p 6 H o 5/2 , (577.21 nm) and 4f 4 ( 5 I)5d 6 G 3/2 →4f 4 ( 5 I)6p 6 H o 5/2 (582.75 nm) of 143 Nd II and 145 Nd II have been measured by collinear laser-ion-beams spectroscopy. The hfs constants A and B of the involved levels have been determined.

Changes in Mean Square Nuclear Charge Radii of Nd II from Optical Isotope Shifts by Collinear Fast-Ion-Beam Laser Spectroscopy

High-resolution collinear fast-ion-beam-laser spectroscopy has been applied to investigate the optical isotope shifts for transition 4f45d6K11/2-(24445)°11/2 of Nd II. From the measured optical isotope shifts, changes in mean-square nuclear charge radii δr2 (fm2) among five even-even neodymium isotopes have been deduced: (142,144) 0.282, (144, 146) 0.242, (146, 148) 0.274, (148, 150) 0.404. The results are in good agreement with experimental data from electronic x-ray spectroscopy and combined optical and x-ray spectroscopy.