A Note on the Cross Section of the Syummetric Charge Transfer between Uranium Ions

The time development operator formalism is presented in order to justify the conventional formulas for the cross section of the symmetric charge transfer process. The formulation clarifies the approximations made in the derivation. The cross section for the process U+U+→U+U is examined. Considering the situation that the lower energy states of the uranium atom/ion are made of two kinds of cores, 5f3(4I) and 5f3(2H), with an energy difference of less than 0.1 eV, and that transfer of one of the 7s-electrons contributes to the cross section of charge transfer to about the same extent as that of the 6d-electron, we obtain a theoretical result which agrees with a recent experimental value at 100 eV.