We investigated the transmission of 7-keV Ne7+ ions through nanocapillaries of rectangular cross-section in phlogopite mica both by experiments and computer simulations. In the experiment, the role of the deposited charge in the transmitted ion intensity and angular distribution was studied. It is found that the rhombic angular profile is degraded during the process of rearrangement of the deposited charge on the capillary walls. Trajectory simulations are performed to understand the shaping of ion beam by the image force at tilt angles within the geometrical opening angle, as well as the degrading of the shaping due to the deposited charge when the tilt angle is larger than the geometrical opening angle. This reveals the interplay of the deposited charge and the image charge on the shaping of the ion beams when transmitting them through nanocapillaries of various geometrical cross sections.

We investigated transmission characteristics of Ne7+ ions through nanocapillaries of rectangular cross-section. The capillaries were produced by chemical etching of ion tracks in phlogopite mica. The two dimensional transmission profiles are rhombic when the capillaries are tilted at angles smaller than the geometrical opening angle given by the aspect ratio of the capillaries. For the angles larger than the geometrical opening angle with respect to the beam direction, the rhombic profile is degrading. Possible reasons for the degrading of the shapes by the deposited charge inside the capillaries are investigated and discussed.

The transition from guiding to scattering in the transmission of 70-keVNe(7+) through mica nanocapillaries of rhombic cross section is studied. Transmitted ions and neutrals are separated and their angular distributions are measured for various tilt angles of the capillaries with respect to the beam direction. The ions and neutrals have different angular profiles and different transmission dependences on tilt angle. The profiles of the transmitted ions are of rectangular shape while bananalike shapes appear for the neutrals. The time evolution measurements during charging up show a shift of the center of the ion angular distribution while that of the neutrals remains fixed. Trajectory simulations are performed by taking the image force and the Coulomb repulsive force from the deposited charge, as well as scattering from capillary walls into account. These show good agreement with the data and how the deposited or image charge deflects and shapes the ionic portion of the beam differently from the neutral part. The experimental separation of the ions from neutrals and their very different behaviors together with simulations gives us further insight into the mechanisms of guiding and scattering in transmission through nanocapillaries.

We report on effects from the geometrical shape of the guiding channels on the ion transmission profile. 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. Our trajectory simulations for the incidence of 14-keV Ne7+ ions give clear evidence that the observed effect is due to the image forces experienced by the transmitting ions. They gain transverse energy due the image charge attraction towards the inner surfaces of the capillary. This leads to a defocusing of the ions leaving the capillaries. Due to the blocking of large deflection angles at the exit of the capillary, the transmitted ion beam is tailored into certain geometrical patterns.

Transmission of slow highly charged ions through rectangular nanocapillaries in phlogopite mica is studied. The transmission profiles have rhombic pattern at tilt angles within the geometrical opening angle of the capillaries. The time evolution of ion transmission reveals certain features contributing to the tailored transmission profiles.

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.

The angular distributions of Ne7+ ions transmitted at various kinetic energies of 7-70 keV through muscovite mica nanocapillaries of rhombic cross section are measured. It is found that the transmitted ion beams form a rectangular shape at tilt angles that are small compared to those given by the aspect ratio, i.e., the capillary geometrical opening angle. This shape is retained for all ion energies, but its size changes. The time evolution of the transmitted angular distributions shows that the characteristic profile occurs instantaneously and remains in the stationary state of the transmission, whereas it shifts with the increase of the accumulated incident charge. At tilt angles of the capillaries larger than their aspect ratio, the shape in the transmission profile gets distorted from the rectangle by the deposited charge. Combined with trajectory simulations we show the observed shaping effect is due to the image force seen by the ions, interplaying with a deflection by the deposited charge on the capillary walls.

This thesis is based on experimental investigations of transmitting slow highly charged ions through nano-structures of various cross-sections. Transmission through rhombic and rectangular nanocapillaries in muscovite and phlogopite mica, respectively, is used to study the guiding and shaping of highly charged ion beams. The two-dimensional angular distributions of the transmitted ions reveal that slow highly charged ion beams are tailored into rectangular and rhombic shapes after passing through the capillaries of rhombic and rectangular cross-sections, respectively. These transmission profiles are maintained for tilt angles within the geometrical opening angle of the capillaries. The ‘incident charge-dependent’ time evolution of the transmission profiles indicates that the tailored shape comes from the image force experienced by the traversing ions and the deposited charge by the incident ions moves the transmission profiles towards higher observation angles with respect to the beam direction. Transmission is also observed for tilt angles larger than the geometrical opening of the capillaries and evidence of charging-up of capillary walls was seen. Other incident charge-dependent features including the increase in angular width and shift of transmitted angular distributions were also observed. Starting from initially charged capillaries, it was found that the deposited charge must be distributed uniformly along the capillary walls to maintain the tailored rhombic shape through rectangular capillaries.

In this thesis, a technique is presented which is successfully employed to investigate directly the formation of charge patches on the walls of a glass capillary by imaging the visible photons emitted due to impact of ions on the walls. These tapered glass capillaries were applied in biological studies of cell damage by ion impact and the technique provides a new way to directly observe the development of ion-guiding in these capillaries. With the help of this technique the mechanism of ion-guiding can be controlled and optimized.

We also review the transmission characteristics of slow highly charged ions through nanometer thick foils and present the results of transmission of slow highly charged ions through ultra-thin carbon nano-sheets of molecular layer thickness. The observed energy loss is smaller than the calculated one using SRIM and agrees rather well with the Firsov model. The transmitted ions also keep their initial charge state up to 98% in a complete contradiction to the electron capture rate predicted by the classical over-the-barrier model. The results suggest that the energy loss of slow highly charged ions in such thin sheets is due to the electronic excitations, without charge exchange inside the target.

Transmission properties of slow highly charged ions through nanometer thick foils are discussed.  We also report on the measurement of the energy loss and the charge states of 46.2 keV Ne¹⁰⁺-ions and 11.7 keV Ne³⁺-ions transmitted through ultra-thin carbon nano-sheets. The sheets had a thickness of 1.2 nm (single molecular layer) and 3.6 nm (three molecular layers). The measured energy loss of the transmitted ions is considerably smaller than the calculated energy loss by SRIM but it is in agreement with energy loss calculated using the Firsov model. The majority of the transmitted ions retain their initial charge state (up to 98%) contrary to prediction by the classical over-the-barrier model. The results suggest that the energy loss of slow highly charged ions in such thin sheets is only due to the electronic excitations, without charge exchange inside the target.

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.