CARBON FOIL THICKNESS DEPENDENT ELECTRON YIELDS INDUCED BY SWIFT HIGHLY-CHARGED IONS

We measured electron yields from the beam entrance and exit surfaces o f thin carbon foils (d approximate to 4-700 mu g/cm(2)) bombarded with swift (E(p)/M = 13.6 MeV/u) highly charged (q = 16-18) Ar ions. The d ependence of the electron yields on target thickness d is analyzed wit hin the framework of a phenomenological semiempirical model. We obtain ed electron transport lengths of high energy (E much greater than 100 eV) delta-electrons and diffusion lengths of slow electrons (E much le ss than 100 eV), The projectile velocity dependence of these transport lengths is investigated by comparing our present results for 13.6 MeV /u Ar with results obtained with 0.1 MeV/u Ne, 1 MeV/u C, 3.9 MeV/u S and 74 MeV/u Ni. We also discuss the relation between electron yields and the electronic stopping power.