Role of conductivity for the production of charge patches by ions guided in capillaries

Guiding of 3-keV Ne7+ ion through nanocapillaries in highly insulating polymers was studied. By means of simulations it is made evident that oscillations of the ion emission angle after transmission through capillaries reveals charge patches within the capillaries. The creation and removal of the charge patches depend on the conductivity of the capillaries so that a relationship of the conductivity and the oscillatory structure of the mean ion emission angle can be established. Experimentally significant differences were found in the ion fractions transmitted through capillaries prepared in polycarbonate (PC) and polyethylene terephthalate (PET). For PC the ion fraction decreases with inserted charge indicating blocking effects on the transmitted ions whereas for PET the ion transmission was found to be almost constant even for long term irradiation. The observed differences were attributed to different conductivities of the capillaries in the polymer materials. This attribution was supported by additional measurements concerning the oscillatory structures of the ion emission angles.