Compilation of the data-base of symmetric charge-transfer cross section

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Cross sections for resonant charge transfer between atoms and their positive ions have been calculated for all non-transition elements in the range of low and intermediate collision velocities (<la.u.), and experimental data obtained since the 1930's have been compiled. The cross sections have been calculated by the impact-parameter and close-coupling methods. To solve the one electron time-dependent, spinless electronic wavefunction in a two atom system, the wavefunction was expanded in terms of a set of traveling atomic wavefunctions centered about either nucleus. As the eigenfunction of each atom, Hartree Fock Slater wavefunctions were used. The calculated results are in fairly good agreement with the compiled experimental results for the thoroughly studied elements and, thus, provide a useful interpolation/extrapolation of the experimental data.A modified crossed-beam apparatus to measure charge-transfer cross sections of metallic elements in wide impact-energy range (10-1000eV) has been developed. The charge-transfer cross section between a gadolinium atom and its positive ion has been measured with a crossed-beam apparatus which features primary ion production by photoionization with a tunable dye laser. The initial state of Gd ions were controlled to be in the ground state by tuning the photon energy to be closed to the ionization potential energy. The Gd ions in the ground states were collided with the Gd atoms in the ground and some excited states. The cross sections as a function of impact-energy (30-1000eV) were successfully obtained. The cross section at 1000eV was 3.3x10^<-14>cm^2. The obtained cross sections are larger than those of^ハother elements obtained experimentally in the past.