Search for projectile charge dependence of kinetic electron emission from clean polycrystalline gold

Total yields for ion-induced electron emission from atomically clean polycrystalline gold have been measured accurately (total errors less than or equal to +/-5%) for normal incidence of Cq+ (q less than or equal to 5)-, Nq+(q less than or equal to 6)-, Oq+(q less than or equal to 7)- and Neq+(q less than or equal to 9) ions with impact velocities from below 10(5) m/s (exclusive potential emission/PE regime) up to 10(6) m/s (5 keV/amu). Contribution from kinetic emission (KE) to these total yields was studied by taking into account the respective PE yields and precise determination of the KE impact velocity threshold for corresponding singly charged ions. For given ion species Z(1) and impact velocity we have investigated whether KE yields depend on the ion charge state q. From q = 1 toward 3 a slight decrease with q has been found, but there are no significant differences in KE yields at higher q values. Results are discussed in view of the q-dependence for relevant KE mechanisms. (C) 1999 Elsevier Science B.V. All rights reserved.