Nuclear microprobe: A microanalytical technique in biology

The nuclear microprobe is an instrument of elemental microanalysis, with imaging capabilities, particularly suitable for the measurement of trace elements in biological tissues. It makes use of the numerous types of emitted radiations resulting from the interaction of MeV charged particles with the matter. Particle Induced X-ray Emission, Rutherford Backscattering Spectrometry, Nuclear Reaction Analysis and Scanning Transmission Ion Microscopy are analysis or imaging techniques which can be simultaneously carried out using a particle microbeam. The analysis may be routinely achieved at the part per million level of sensitivity, the micron spatial resolution and in multi-elemental mode. In addition, the combination of elemental mapping with high resolution STIM imaging allows the technique to provide a wealth of useful information on the sample under investigation. This paper is an introduction to ion beam technique of microanalysis. Basic principles are briefly discussed as well as practical aspects concerning the sample preparation and the beam damages.