Double electron capture in Ne10++He collisions in the sub-keV energy range

We studied mechanisms for double electron capture in slow Ne10++He collisions using the method of high-resolution Auger-electron spectroscopy. Projectile energies as low as 500 eV were investigated. At such very low energies the production of the configurations 3lnl′ (n⩾6) of non-equivalent electrons is found to become dominant. The comparison of the experimental data with model calculations indicates that the non-equivalent electron states 3lnl′ (n⩾6) are created by dielectronic mechanisms due to electron-electron interaction. At sub-keV energies the major contribution to double electron capture is due to dynamic electron correlation.