Hard Collision between Charged Particle and Atom
- Practical Electron Microscopy and Database -
- An Online Book -

http://www.globalsino.com/EM/  



 

 

=================================================================================

As shown in Figure 4428, the charged particle experiences Coulomb interactions with the nuclei and the orbital electrons of the atoms in a matter when it travels through the matter. These interactions can be divided into three categories depending on the impact parameter b compared with the atomic radius a: a) Interaction with the external nuclear field (bremsstrahlung production) for b << a; b) Interaction with the orbital electrons for b ≈ a (hard collision); c) Interaction with the orbital electron for b >> a (soft collision).

Radiative, hard and soft collisions. b is the impact parameter and a is the atomic radius

Figure 4428. Radiative (a), hard (b) and soft (c) collisions. b is the impact parameter and a is the atomic radius.

 

=================================================================================