[en] The transmission of Xe¹⁰⁺ ions, with incident kinetic energies of 200–500 keV, through polycarbonate capillaries, with a diameter of 150 nm and a length of 30 μm, has been studied using a one-dimensional position sensitive detector. The transmitted ion yields were measured as a function of the tilt angle. The results are used to evaluate the guiding angle, which is a measure of the guiding power specifying the capability of insulating capillaries to guide ions at equilibrium. Following the semi-empirical scaling law, the potential in the entrance region in this work is nearly an order of magnitude larger than that proposed by low energy data. (paper)