Valence electron momentum distributions in zinc

The valence 4s electron momentum distribution in zinc has been measured using EMS at a total energy of 1000 eV. It is in good agreement with the momentum distributions given by the Hartree-Fock 4s wavefunction. The (3d) -1 cross section has also been measured and excitation of the 3d 10 4p( 2 P 1/2 2 P 3/2 ) ion states is observed, showing the importance of the 3d 10 4p 2 configuration in the ground state. This is the first direct measurement of an orbital momentum distribution for an atomic orbital which is not occupied in the independent-particle (HF) model. Detailed CI calculations have been carried out on both the target ground state and final ionic states.