Pixe Analysis Research in Lund

Protons or a-particles from a 3 MV tandem Pelletron are used to induce characteristic x-rays, which are detected by a Si(Li)-detector. To optimize the quality and speed of data taking we use an absorber with a hole, pile-up rejection and on-demand beam. Forty samples may be entered simultaneously into the vacuum, and their positioning is operated by pushbuttons. The system is prepared for minicomputer steering. PIXE is combined with analysis of back-scattered particles and in some cases ¿-ray detection from a 19F(p, ¿¿) 16O-reaction. At different stages of development we have a bent-chrystal spectrometer, microbeam and facilities to extract the beam from vacuum. In the introduction of PIXE to applied fields, it is important, that physicists take part in identifying, planning and performing suitable projects e. g. experiments where rapid multielemental analysis of many samples is crucial. In Lund we investigate the elemental composition of size-fractionated airborne particles from work environments and ambient air. The objectives are then to learn about sources, transport and deposition of particles and to contribute to the understanding of relations between exposure and health effects. We are also developing procedures for trace elemental analysis of water. Detection limits in the range of 0.1 ppb have been demonstrated. In other projects in progress biological and mineralogical samples are analysed.