In-air STIM with a capillary microprobe

A nuclear microprobe based on a tapered glass micro-capillary has been developed. The MeV ion beam can be collimated to a diameter of approximately 1 μm without the need of ion optical lenses. Due to the small gas leakage through the capillary opening, the beam can be taken into air without any membrane or special differential pumping. Samples can be raster scanned by means of a piezo-driven XY stage. For Scanning Transmission Ion Microscopy (STIM), the energy of the transmitted particles is measured by a miniaturized and radiation hard high resolution gas ionization detector. Technical details are given and examples for STIM imaging and single spot PIXE measurements are shown.