Study of cross sections for the loss of outer 1s, 2s, and 2p electrons by fast ions and atoms of light elements

In the case of light-element ions propagating with velocities V = 1.83 and 3.65 au in H2, He, N2, Ne, and Ar, the loss cross sections σi, i+m for m electrons (m = 1, 2, 3) are considered. The partial loss cross sections σi(nl) for one of the outer 1s, 2s, or 2p electrons are determined using the obtained data. It is shown that the experimental cross sections for the loss of the 1s and 2s electrons by positive ions qualitatively agree with the theoretical values calculated in the Born approximation. In the case of the ion velocity V = 1.83 au, the cross sections σi for 2p electrons are greater than the cross sections σi (1s) and σi (2s) by a factor of 1.2–3 for the same binding energies of electrons in the ion (Inl > 20 eV). It is found experimentally that, at V = 1.83 au, the cross sections σi (2p) for Inl ∼ 10–20 eV are less than the cross sections σi (1s) by a factor of 2–3, which is probably caused by a decrease in the screening parameter (θ2p < 1) of the outer shell of atoms.