Importance of subshell coupling in L-shell ionization by low-velocity heavy ions

Data for available L-subshell ionization caused by slow and heavy ions (Z 1 = 6, 7 and 8) are compiled and compared with the prdictions of the ECPSSR theory with and without the intra-shell (IS) coupling. It has been observed that the standard ECPSSR without Is is inadequate to predict quantitatively the L-subshell cross section data at low projectile velocities. The inclusion of the IS effect somewhat worsens agreement with experiment for the L 1 -subshell ionization, substantially improves it for the L 2 subshell, and plays essentially no role in an analysis of L 3 -subshell data which are fairly well predicted by the standard ECPSSR theory. The quantitative validity of such conclusions may be questioned because they rely on an approximate treatment of the IS effect.