Applications of Microbeams Produced by Tapered Glass Capillary Optics

Production of ion microbeams using tapered glass capillary optics was introduced more than 10 years ago. This technique has drawn attention in terms of both its peculiar transmission features and application to ion beam analysis. The transmission mechanism based on a self-organized charge-up process for keV-energy ions was observed for the first time in an experiment using a multitude of nanometer-sized capillaries in a polymer foil. The same mechanism can be seen for the transmission of keV ions through a single tapered glass capillary. The transmission experiments with keV ions showed a delayed transmission, focusing effects, guiding effects, and formation of microbeams. Experiments using MeV-energy ions always aim at applications of microbeam irradiation for material analysis, surface modification, cell surgery, and so on. In this article, the applications of MeV ion microbeams, including the fabrication method of the glass capillary, are reviewed, as well as the experimental and theoretical studies for the transmission mechanisms of keV/MeV ions.

mySpot: a versatile microfocussing station for scanning methods at BESSY II

mySpot is a versatile microfocussing station for scanning methods with resolution down to 1.5 µm, providing a combination of methods which can be performed simultaneously at the same sample position. It is especially designed (but not limited to) for the study of hierarchically structured biological samples. Structural information from different length scales (XRD - crystalline, SAXS - nanometer, Video-microscope - micrometer, sample translation - milimeter) can be combined with chemical information (XRF-mapping, EXAFS, XANES) and molecular information (Raman) providing unique insight into the mutual dependencies of different parameters.The beamline provides focal spot of about 500x50µm, which can be refocused at the sample using capillary optics. Capillary optics is used for two main reasons: 1) the focal spot does not depend on the energy which makes EXAFS and XANES measurements very simple, and 2) the optics is positioned very close to the sample which improves the stability of the focus at the sample. This allows the focal spot of 1.5 µm in 2D scans, as well as very parallel beam for scattering experiments down to 10µm, or volume element of 20µm diameter for 3D XRF mapping.