ABSTRACT
We shall study the elastic collision of a particle of charge ze (e > 0) and mass m with an atom of atomic number Z. An exact formulation of this problem requires the use of a many-body Hamiltonian which describes all the particles of the system, viz., the nucleus, the atomic electrons, and the incident particle which interacts with the nucleus and each atomic electron individually. For the moment, however, we shall make the assumption that for purposes of studying the elastic scattering of the incident particle, the complicated interaction of the incident particle with the constituents of the atom can be summarized by an effective electrostatic potential V in which the incident particle travels. In later chapters, we shall examine to what extent this approximation is valid.
