Guiding of argon ions through a tapered glass capillary

We report results from our recent experiments on guiding of Ar⁸⁺ ions through a single tapered glass capillary with an inlet diameter of 1 mm, an outlet diameter of 0.15 mm and a length of 45 mm. The profile width of the transmitted ion beam and the guiding power of the used glass capillary has been measured at a kinetic energy in the range of 8 keV up to 60 keV using a position sensitive detector. The charge up of the capillary and the evolution of the guiding effect is shown for a tilt angle of Ψ = 4°. The charge up of the inner walls of the tapered glass capillary causes a compression of the incident ion beam by a factor of 8. We found high guiding angles and small profile width of the transmitted ion beam in comparison to the transmission of highly charged ions through nanocapillaries in thin foils. A suppression of the transmission at small tilt angles and low kinetic energies has been observed.