[en] Emerging charge state distributions of 44 MeV/amu ¹²⁹Xe⁴⁴⁺ and 29 MeV/amu ²⁰⁸Pb⁵⁶⁺ transmitted through various solid targets have been measured and analyzed using the GANIL facility. (orig.)

[en] We have determined by means of V.U.V. spectroscopy the polarization of the (3l → 2l') transitions of the C^3+* ion produced in C⁴⁺ - H₂ collisions, in the 0.2 ≤v≤ 0.5 a.u. velocity range. The polarization fraction, quantitatively discussed in terms of alignment of the orbital momentum substates, shows that the m_l substates, in the n=3 shell of C^3+* are not populated equally by the electron capture process. For the 3p- and the 3d-states the polarization increases with the energy, and indicates, for capture to the 3p-state, a dominant population of the m_l=0 substate

[en] Noting the lack of and the increasing need for information concerning heavy ion stripping in the intermediate velocity regime, the authors have studied a large number of ion-target systems experimentally. They present experimental charge state distributions obtained at the GANIL accelerator for several projectiles (36 ≤ Z_p ≤ 92) with energies ranging from 18 MeV/u to 44 MeV/u, emerging from various target foils (4 ≤ Z_t ≤ 79) of natural isotopic composition. The target thicknesses (from 1 microg/cm² up to several mg/cm²) are chosen to cover the pre- and post-charge-state equilibrium regimes. Charge state fractions, mean charge state, charge distribution width, and emerging ion energy are tabulated for each of the 107 projectile-target element-target thickness combinations. They also present an improvement of the semi-empirical formulae proposed by Baron et al. to predict the mean charge states and the distribution widths at equilibrium. These formulae are compared with the available experimental data

[en] De-excitation of doubly excited N⁴⁺ ions produced in N⁵⁺ + He, H₂ collisions has been studied in the 1-5 nm wavelength range. It is shown that the spectrum consists of lines mostly due to states produced by core-conserving capture processes, except for an intense peak around 2.9 nm that could be due to electron capture with simultaneous 2s-2p core excitation. Moreover, many lines can be identified as originating from doublet states. (author)

[en] The population of levels with principal quantum numbers n largely in excess of the n = 3 (most populated level) in the single electron capture by O⁶⁺ from He (at 60 keV) is reported. The n = 4 population involves an ''electron promotion mechanism'' at small internuclear distances (R ≅ 2.5 a_o). Our observations show population of levels up to n = 7 (Rydberg levels) leaving open the theoretical interpretation. (Author)

[en] Photon emission in the 100-200A region following slow 0⁶⁺ + He, H₂ collisions has been analyzed using a new grazing incidence spectrometer. The ions were produced in an ECR type ion source, accelerated to 60 keV, and passed through a target gas cell. Intensity from decay associated with single electron transfer to nl levels is seen, and is used to deduce the relative nl subshell selective capture cross sections. Many lines corresponding to double electron transfer are detected, and discussed in terms of different transfer mechanisms. Several lines are interpreted as due to correlated double capture. We also attribute intensity to the decay of quartet states, formed on metastable 1s2s³S oxygen ion states by one-electron capture. About half of the quartet lines give evidence of non-core-conserving electron transfer

[en] Absolute X-ray and VUV emission cross sections have been measured for collisions of H-like C⁵⁺ and N⁶⁺ ions with H₂ and He in the 0.18 au < υ < 0.55 au velocity range. From the comparisons of both types of measurements it is possible to determine to what extent the population of the 1s2p state is due to single electron capture and to double capture followed by autoionization. Our X-ray and VUV data are compared with electron capture cross section data from other authors, obtained either by electron spectroscopy or by charge state analysis. Mostly a good agreement with these data is found. (Author)

[en] Single- (SC) and double-electron capture (DC) have been studied for collisions of Ar⁸⁺ with He using x-ray and vacuum ultraviolet (vuv) spectroscopy at a collision energy of 80 keV as well as translational-energy spectroscopy (TES) at lower collision energies (8 keV). It is shown that both processes involving the ground-state ion terminate in vuv photon emission, i.e., nonautoionizing levels are populated. The SC, by the long-lived metastable species Ar^8+* (2p⁵3s)³P_0,2, populates mostly the Na-like core-excited levels with n=4: Ar^7+* (2p⁵3s ³P 4l)^2,4L_J. With the use of calculated decay and autoionization rates, the measured vuv spectra are analyzed and compared with the TES results and the Auger spectra measured by other authors. It is shown that the stabilization of these core-excited states is both radiative and autoionizing. The DC by the metastable projectile is not yet fully understood