Particular Electromagnetic Processes in Collisions with Atoms and Nuclei

Abstract

When a charged particle a enters a large target, it continually loses energy to the atomic electrons, either by atomic excitation or by ionization (electron emission). Typical energy losses in single collisions

$$ \Delta {E_n} = {E_{aL}} - {E_{aL}}(n) $$

((1.1))

(n characterizes the final state of the excited target) are much smaller than the kinetic energy of particle a. The particle then moves approximately on a straight line, with an energy loss per target density

$$ \varepsilon ( \equiv - {N^{ - 1}}dE/dx) = \sum\limits_n {\Delta {E_n}\int {d{\sigma _n} = \sum\limits_n {\int {\Delta {E_n}dtd{\sigma _n}/dt} } } } $$

((1.2))

.