[en] Lines occurring as satellites on the long-wavelength side of the 3d¹⁰--3d⁹4p resonance lines of Ni-like ions have been investigated with a low-inductance vacuum spark and a 10.7-m spectrograph for the elements Y, Zr, Nb, and Mo. The lines are interpreted as 3d¹⁰4s--3d⁹4s4p and 3d¹⁰4p--3d⁹4p² transitions in the Cu-like ions Y XI, Zr XII, Nb XIII, and Mo XIV and 3d¹⁰4s²--3d⁹4s²4p transitions in the Zn-like ions Y X, Zr XI, Nb XII, and Mo XIII. The spectra of the Cu-like ions were interpreted by generalized least-squares fits for the energy levels of the sequence of four ions. Thirty-nine levels of 3d⁹4s4p were interpreted simultaneously with a root-mean-square deviation of 122 cm^-1; forty-four levels of 3d⁹4p² were interpreted in the same way with a root-mean-square deviation of 20 cm^-1. Line identifications and energy levels were obtained for the 3d¹⁰7p configuration of the Cu-like ions Y XI--Mo XIV

[en] The performance and the high-temperature technology of a modular ion source system with long lifetime, comprising a FEBIAD and a thermal ion source is described. Both sources have a variable-temperature and variable-material option for the catcher. The problems with the entrance window of the ion source at high temperature are discussed. The compact design of the FEBIAD source and the effective heat shielding result in a cold-spot temperature of approx. equal to 1900⁰C with 400 W of power input. The intrinsic delay is of the order of 10 ms. The off-line ionization efficiency is 23% for krypton, 48% for xenon and 76% for mercury, the total ion current being less than 10 μA. The thermoionizer is an electron bombardment heated tungsten body of 0.3 cm³ volume permitting temperatures up to 2500⁰C under on-line conditions. The on-line overall efficiencies for a large variety of isotopes is presented for both sources, reaching up to approx. equal to 40% within the halflife range from 50 ms to several minutes. (orig.)

No abstract available

[en] Excitation energies and oscillator strengths for electric dipole allowed transitions between low-lying states in P IV are calculated using the configuration-interaction wavefunctions. The strong interaction between the 3sνd ¹D bound and continuum series and the 3p²¹D perturber is represented by correlation orbital. The calculated term energies and the experimental values are in very good agreement. The agreement between length and velocity of the oscillator strengths and other available results is good. (orig.)

[en] MCHF calculations recently predicted a positive binding energy for the 4p electron in the 4s²4p ²P state of Ca^-, in good agreement with experiment. These calculations were extended to other ns²np systems and, in cases where the (n - 1)d shell of the atom was unfilled, theoretical calculations predict the existence of stable, negative ions. These calculations modeled the atom as (Core)ns² and the ion as (Core)ns²np and included correlation only among the outer electrons. Similar calculations have been performed for Rb and Cs where the neutral atom can be modeled as (Core)ns. In this case, the interesting question is whether (Core)nsnp ³P is a bound state, but because a fewer electrons outside the core, the calculations were able to include core polarization or correlations with the core. A survey of some of these results is presented. (orig.)

[en] A simple numerical method of constructing orthogonal fine structure parameters is suggested. The possibility of estimating the parameters from experimental energy levels is discussed. Parametric fitting to the 2p⁵3d configuration in Al IV is carried out as a numerical example. (orig.)

[en] The analysis of the RbI-like spectrum Mo VI has been extended to include a total of some 110 classified lines and 44 energy levels belonging to the one-electron configurations 4s²4p⁶(¹S)nl with n ranging up to 9 and l up to 7. The analysis is based on recordings of vacuum spark spectra made at Lund in the region 230-2350 A, complemented by a list of lines from 2193 to 6336 A observed and identified by Romanov and Striganov in a Penning type arc discharge. The one-electron level system is partly mixed with core-excited configurations, not treated in the present paper. Especially the nf series is strongly perturbed by 4s²4p⁵4d², and an anomalous behaviour of the ng series is explained by interaction with the ²G term of 4s4p⁶4d². The ionization limit, derived from 6h, 7i and 8k by means of the polarization formula, is found to be 555 132+-2 cm^-1. (orig.)

[en] The spectrum of Ni VII has been photographed in the 190-265 A region using grazing incidence vacuum spectrographs. More than 400 lines have been classified. In the 3d⁴-configuration 32 of the 34 possible levels and in the 3d³4p-configuration 93 of the 110 levels are established. The lines and levels which have already been published are confirmed. The configurations are described both with the conventional Slater-Condon parameters and the recently developed orthogonal parameter set. The conventional set yields a standard deviation for the levels in the 3d⁴ configuration of 46 cm^-1 and of 163 cm^-1 for the levels in the 3d³4p configuration. With the orthogonal set this decreases to 3.5 cm^-1 and 130 cm^-1 respectively. As a consequence of the perturbation by the inner shell excited 3p⁵3d⁵ configuration the levels of the 3d³(²F) 4p ³F term show an average deviation of approx. -1400 cm^-1 from their calculated values. The other levels can be described very well without taking this perturbation into account. (orig.)

[en] In this paper we calculate the gf-values of some transitions of YII and ZrII to test the reliability of the commonly used values for astrophysical applications. For ZrII we show the inadequacy of the values used at he present time. (orig.)

[en] Results of numerical calculation of storage of heavy element multicharged ions in electron rings of a collective accelerator are presented. The ring is placed in the atmosphere of residual gas (nitrogen). The average charge of ions in the ring increases in the result of the electron shock ionization. The storage of xenon ions at the pressure of residual gas 3x10^-9 torr and uranium ions at the pressure of 2x10^-9 torr is investigated. The electron ring is completely neutralized by nitrogen ions for 50-100 ms. The conclusions are made that at the parameters of electron rings taken it is possible to obtain completely stripped xenon nuclei for approximately 0.1 s at the pressure of residual gas less than 10^-9 torr and uranium nuclei for approximately 0.5 s at the pressure less than 10^-10 torr