The irradiation with charged particles always means irradiation with positively charged particles ranging from protons to heavier nuclei. The most important inter­actions of the positively charged particles are similar to the interactions of the alpha particles with matter (see Table 5.2). For analytical purposes, protons are

% weight

used most frequently. In some cases, alpha particles are also applied. For example, in Rutherford spectroscopy, an example of which was presented in Section 5.2.2, the scattering of alpha particles from the nuclear field is used to obtain information on the sample.

Besides the interaction with the nuclear field, the interaction with the orbital electrons and the nucleus can be used in the analysis. The positively charged parti­cles, similar to X-ray and gamma photons, or electrons, can eject electrons from the K or L orbitals, providing qualitative and quantitative analytical tools. This ana­lytical method is particle-induced X-ray emission (PIXE; see Section 10.2.5.1).

The nuclear reactions of charged particles can be used for analytical purposes in the same way as NAA. The method is called “CPAA” or “charged particle-induced nuclear reaction analysis (CPINRA).” In addition, the prompt gamma photons of the nuclear reactions with charge particles can be measured in particle-induced gamma emission (PIGE; see Section 10.2.5.2).