Focusing of 90Â keV O6+ ions through a single tapered glass macrocapillary

Transmission of O6+ ions through a tapered glass capillary with a diameter of 0.2 mm at the exit has been investigated, in which high incident current with a magnitude of several nA/mm2 was employed. The majority of ions passing through the capillary deviated from their incident directions, but kept their charge state and energy even when the capillary was tilted with an angle less than the opening angle. The present results indicate that the focusing effect can also be obtained in the transmission of medium energy ions through a tapered glass macrocapillary and show a rough linear relationship between the transmission probability and the ions perpendicular energy.