The Debye screening distance which was introduced in the context of ions in an electrolyte by Peter Debye and Erich Hückel in 1923 provides a natural dividing line between the small scale collisions of pairs of particles and the large scale collective effects such as plasma oscillations. In this article, considering both close and distant collisions, we drive at an equation from which we show that the energy losses occur in quantum jumps of ħωp, where ωp is plasma frequency. Some metallic conductors behave like plasmas at high frequencies. The alkali metals like Li, Na, K, Rb and Cs are observed to show a sharp transition from opaque to transparent at the characteristic ultraviolet wavelengths.
Energy loss, Plasma, Quantum Jumps, Alkali metals
