We report on an unexpected effect of tailoring transmission profiles of Ne7+ ions through nanocapillaries of rhombic and rectangular cross sections in mica. We find that capillaries of rhombic cross sections produce rectangular shaped ion transmission profiles and, vice versa, that capillaries of rectangular geometry give a rhombic beam shape. This shaping effect only occurs for transmitted ions and is absent for the small fraction of neutralized particles. The experimental findings and simulations of the projectile trajectories give clear evidence that the observed effect is due to the image forces experienced by the transmitting ions. This novel beam shaping mechanism suggests applications for the guiding, focusing, and shaping of ion beams.

Time evolution of angular distributions of transmitted ions through SiO2 nanocapillaries wasmeasured under defined initial conditions: already charged, as well as fully dischargedcapillaries. We find distinct charge patterns and describe them quantitatively with the help of amodel calculation. This results in a pattern of a few number of charge patches, guiding ions inthe stationary state of transmission. For the already charged capillary membrane, we show a“memory effect” in the form of a double peak structure in the transmitted angulardistributions. The time evolution of these structures reflects charge relaxation andrearrangement of the charge patches. The re-arrangement of the charge patches is much fasterthan the discharge, suggesting that the charge relaxation inside the capillaries can be drivenby the incident charges, such as a Frenkel-Poole process.

A new laboratory for highly charged ions is being built up at Stockholm University. A fully refrigerated electron beam ion trap (R-EBIT, 3 T magnet, 30 keV electron energy) was installed. It was used for spectroscopic studies, ion cooling experiments, electron ion collisions, and highly-charged ion surface studies. Here we report on an upgrade of this EBIT to a ``Super EBIT'' (S-EBIT, 4 T magnet, 260 keV electron energy). The high-voltage trapping system, the ion injection as well as the extraction scheme of S-EBIT and the LabView based operational system of S-EBIT are described.

The guiding of highly charged ions through SiO₂ nano-capillaries has been investigated by our group, using 7 keV Ne⁷⁺-ions. We studied in particular the transmission of ions incident at angles greater than the angle given by the capillary aspect ratio as a function of charge incident on the capillary membrane. In this report we show the re-arrangement of charge patches inside the capillary by observing the evolution of the two-dimensional angular distributions of the transmitted ions.

We investigated the time evolution of the dynamically shifting distribution of 7 keV Ne⁷⁺ ions guided through nanocapillaries in SiO₂. We present evidence for a small number of charge patches, formed sequentially in the charging-up process, guiding the ions. We show that the charge patches are distributed along the whole length of the capillaries and that they are maintained in the equilibrium state of transmission. The interpretations are supported by model calculations.

The guiding of highly charged ions through nanocapillaries in different insulating materials, such as polyethylene terephthalate, SiO₂, and Al₂O₃ has been investigated by our group, using 7 keV Ne⁷⁺ ions. We find transmission of ions incident at angles larger than the angle given by the capillary aspect ratio in all these materials. The measured angular distributions, however, vary with the membrane material. In this report we compare the experimental findings with the different membranes.

We report on an unexpected effect of tailoring transmission profiles of Ne⁷⁺-ions through nanocapillaries of rhombic and rectangular cross sections in mica. We find that capillaries of rhombic cross section produce rectangular shaped ion transmission profiles and, vice versa, capillaries of rectangular geometry give a rhombic beam shape. This shaping effect only occurs for transmitted ions and is absent for the small fraction of neutralized particles. The experimental findings and simulations of the projectile trajectories give clear evidence that the observed effect is due to the image forces experienced by the transmitting ions. This novel beam shaping mechanism suggests application for guiding, focusing, and shaping of ion beams.