3. Efficient sections

3.1 Effective cross-section of ionization by charged particles

Lightly charged particles (proton or alpha) are most often used as projectiles. In the energy range under consideration, i.e. 0.5 to 5 MeV per nucleon, theoretical models to account for the ionization of deep atomic layers are based on the Coulombic interaction between a bound electron and the nucleus of the incident charged particle. This is referred to as a fast or direct collision, and the collision partners can be considered as point charges. Among the most commonly used models are the Plane Wave Born Approximation (