Simulation of ion guiding through insulating capillaries:: Effects of inter-capillary interaction

Nanocapillaries through insulating foils (PET or "Mylar") have received interest as a target for beams of slow highly-charged ions. Transmission of projectiles in their initial charge state have been measured for angles of incidence larger than the geometrical opening angle. Ions are guided along the capillary axis and do not closely interact with the inner walls of the capillary. We have developed a classical trajectory transport theory of this self-organized guiding process that relates the microscopic charge-up with macroscopic material properties and includes multi-capillary effects on a phenomenological level. Transmission coefficients are investigated, yielding good agreement with experimental data. The dependence of angular spread of transmitted ions on the angle of incidence and incident energy can be correctly described. (c) 2006 Elsevier B.V. All rights reserved.