Particles, charged, inelastic collisions

Inelastic collisions of swift, charged particles with matter are completely described by the distribution of generalized oscillator strengths (GOS s) characterizing the collision. These quantities, characteristic of excitation in the N-electron target (or, in fact, of a dressed projectile as well [1]) from some initial state 0) to a final state n) and concomitant momentum transfer, can be written... 

A fast neutron loses its energy by interaction with an atomic nucleus and ejection of a proton. A slow neutron is absorbed by the nucleus giving rise to a radioactive atom which may decompose by the emission of a /1-particle or y-ray. Charged particles in general lose their energy by inelastic collisions with the electrons within an atom leading to the ejection of an electron. 

M. Inokuti, Inelastic collisions of fast charged particles with atoms and molecules - the Bethe theory revisited, Rev. Mod. Phys. 43 (1971) 297. 

Collisions that result in ionization or excitation are called inelastic collisions. A charged particle moving through matter may also have elastic collisions with nuclei or atomic electrons. In such a case, the incident particle loses the energy required for conservation of kinetic energy and linear momentum. Elastic collisions are not important for charged-particle energy loss and detection. 

The solution of the problem of inelastic collision in the Born approximation yields a differential cross section valid both for electrons and for any charged particle. 

Charged particles can interact with matter and lose energy in two ways (i) emission of electromagnetic radiation and (ii) inelastic collisions. A brief review of both processes is now presented. 

No energy loss is possible from elastic and inelastic collisions involving the nucleus of the absorbing medium and the heavy charged particle. 

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