Energy losses and their straggling for H+ and He+ ions with energies of several hundreds of keV on their passage through metal and polystyrene films

Energy losses and their straggling for H+ ions with energies between 120 and 480 keV and for He+ ions with energies between approximately 150 and 1300 keV are measured in thin Al, Cu, Ag, Au and polystyrene (Csub(8)Hsub(8))sub(m) films. The energy loss straggling data are discussed on the basis of current theories. It is shown that in the ion energy ranges under study an important (and for the He ions - a dominant) role is played by auxiliary straggling mechanisms connected with fluctuations of the ion charge and correlations between the energy losses on interaction between the ion and several electrons simultaneously. Much better agreement between the experimental data and calculations can be attained if these mechanisms are taken into account