Production of nanometer sized charged particle beams with glass capillary

We have developed methods to produce nanometer-sized beams of keV highly charged ions and MeV charged particles with various glass-made beam optics. The beam size of 900 nm was obtained for keV ions. (1) For keV energy region, a focusing effect for an Ar8+ beam of 8 keV through a cm-long tapered capillary was obtained with a density enhancement of the transmitted beam compared with that of the input beam, which increases from 1 to 6 as the input current decreases from 30 pA to 0.8 pA. (2) For 4 MeV He2+ beam, a 100 times density enhanced beam by a cm-long tapered capillary with a closed outlet was utilized to irradiate a biological cell in liquid. The range of the beam was controlled by the closed outlet with accuracy of ∼1 μm. Moreover, muon beams with an energy of 13 MeV were also focused with a density enhancement of a factor of ≅2 using 40 cm-long tapered glass tubes. (author)