For particle induced X-ray emission (PIXE) measurements, the solid angle of the detector is one of the most important parameters for fast and efficient experiments. Using a high solid angle, the required measuring time is significantly reduced under beam conditions, further reducing the sample’s damage. To approach the solid angle above 0.5 sr, a segmented annular detector can be employed and has been installed at the ion microprobe end station of the Jožef Stefan Institute accelerator laboratory. The Rococo 2 (PNDetector, Germany) detector consists of an SDD chip with a central hole of 1.8 mm and four crescent- shaped segments, mounted on a 45° angled mechanic. Each segment is protected by a Be window and pre-amplifier which provides a readout for each segment individually, achieving the 130 eV energy resolution [1]. The key advantage of using such a detector is in summing all segment’s spectra to increase the statistics of measured data. This can be done in GeoPIXE II software [2]. This approach is beneficial when only a small ion dose can be applied to the sample, for example for biological samples. An example of this approach to data analysis from biological samples will be presented and discussed. The segments’ arrangement also allows the 3D reconstruction of the surface topography [3], for which a generalized approach to data analysis and 3D surface reconstruction has also been developed in our lab and will be presented.
