Low energy ion transmission through a conical insulating capillary with macroscopic dimensions

Transmission of 1 keV single charged nitrogen ions through a macroscopic tapered borosilicate glass capillary is studied theoretically and experimentally. Measured time trend of the transmission for different low beam intensities are given. They are compared to realistic microscopic calculation that allows simulating the transmission of charged particles through a conical capillary with macroscopic dimensions. We show clear evidence that a low energy ion beam with intensities in the pA range can be transmitted and focused through tapered macroscopic insulator capillaries.