Physical Review B : May 1, 1999 , Volume 59, Issue 17
R. Neugebauer, R. Wuensch, T. Jalowy, K. O. Groeneveld , H. Rothard
, A. Clouvas, C. Potiriadis.
Secondary electron emission near the electronic stopping power maximum.
We report on measurements of light ion (Z = 2) and heavy ion (Z = 14)
induced electron emission yields from the entrance and exit surfaces
of thin carbon foils near the electronic energy loss per unit path length
(dE/dx) maximum. At constant dE/dx, secondary electron yields are lower
for high projectile velocities than for lower projectile velocities.
This velocity effect, which is well known for secondary ion emission,
is observed for backward electron emission for both He and Si. In the
case of Si projectiles such a velocity effect is also observed for forward
electron emission. The results can be qualitatively understood in the
framework of recent electron transport and nuclear track models.