have built an experimental apparatus to measure the secondary electron emission from solid surfaces. Two different measurements (with a pulsed ion beam technique and a continuous beam) were employed to determine the secondary electron emission coefficients of 1000-Angstrom silicon dioxide film for 200-eV He+. Only the pulsed ion-beam method could determine a secondary electron emission coefficient of 0.547 because the surface charging effect was reduced during measurement. The secondary electron emission coefficients showed a dependence on the kinetic energy of incident He+ ranging from 50 to 300 eV. In addition, the secondary electron emission coefficients of MgO film were obtained for five low-energy noble ions using the pulsed-beam technique. These MgO coefficients clearly showed that the heavier ions showed lower secondary electron emission values than those of the lighter ions with kinetic energy ranging from 50 to 225 eV. (C) 2003 Elsevier Science B.V. All rights reserved.