Читать книгу Essentials of Nuclear Medicine Physics, Instrumentation, and Radiation Biology - Rachel A. Powsner - Страница 51

Charged particles of sufficient energy may also transfer enough energy to an electron (generally one in an outer shell) to eject the electron from the atom. This process is called ionization (Figure 2.9). This hole in the outer shell is rapidly filled with an unbound electron. If an inner shell electron is ionized (a much less frequent occurrence) an outer shell electron will “drop” into the inner shell hole and a characteristic X‐ray will be emitted. Ionization is not limited to the interaction of charged particles and matter, the photoelectric effect and Compton interactions are examples of photon interactions with matter that produce ionization.