RBS: Introduction

The major points to learn are:

1. Scattering is proportional to the squares of both the charge of the incident particle and the target nucleus.

2. The number of scattered particles varies as the inverse square of the kinetic energy of the incident particle.

3. Scattering is inversely proportional to the fourth power of sin(θ/2), where θ is the scattering angle.

4. For thin targets, the scattering is proportional to the target thickness, t.

• Consider an ion of charge z, mass m and initial kinetic energy E₀ being scattered elastically from a stationary nucleus of charge Z and mass M purely by the Coulomb force. The final energy E of the scattered ion is a function of the angle of scatter θ from the initial direction and the ratio M/m.

Figure 18.02: Schematic of interaction between ion and nuclei.