Higher-order Z/sub 1/ effects and effects of screening by bound K electrons on the electronic stopping of channeled ions
The stopping power in )111) Au for channeling ions which have not changed charge has been measured for bare nuclei for Z = 1 - 5 at 3.5 MeV/amu, and for ions bearing 0, 1, and 2 bound electrons for Z/sub 1/ = 1 - 9 at 2 MeV/amu. An effective screening of approx.0.9e per electron is obtained. For the bare nculei, deviations from simple Z/sub 1/ /sup 2/ scaling are reported. At 2 MeV/amu an increase of 3.5% in S/Z/sub 1/ /sup 2/ is seen from H to He, 3% from He to Li; but no differences are seen from Z/sub 1/ = 5 - 9. However, at 3.5-MeV/amu deviations of as much as 20% per Z/sub 1/ are observed.