The role of Al-Auger electrons in kinetic electron emission from Al surfaces by slow Ne+ and Na+ ions

This work reports measurements of energy distributions and yields of electrons emitted in the interaction of slow singly charged neon and sodium ions with Al surfaces. The measurements show the strong interplay between different emission mechanisms, such as projectile and target Auger electron emission, decay of bulk plasmons and electronic collision cascade. These results indicate that the Auger decay of Al-2p excitations occurring in binary atomic collision between recoiling target atoms, is the dominant primary excitation mechanism. Measurements performed using sodium projectile show that a significant contribution to the total electron emission yield comes also from a vacancy transfer process that produce Al-2p excitation by a vacancy transfer process in asymmetric collisions between target atoms and incoming ions that have survived neutralization at the surface.