K-photoionisation of atomic carbon: shake up processes

We evaluate the shake up process in the K– photoionisation of atomic carbon, i.e. the 2s → 2p and 3s, and 2p → 3p shake up excitations, within the photon energy range 25 to 45 Ry. As in the atomic boron case, the 2s → 3s excitation is still relatively strong and due to configuration interaction effects dominates the 2p subshell excitation to 3p. The conjugate shake up 2s → 2p is 3% near 45 Ry, decreasing slowly as expected. This infers that the shake off process would lead mostly to terms related to the configurations 1s2s2p2 with a percentage of about 20%.