Excitation of lattice motion by interaction with large amplitude electron plasma oscillations

Fast heavy-ion bombardment on solids in which a “free-electron”-limit for high excitations exists, generates plasma oscillations with very large amplitudes, as found in no other process. This should uniquely enable the observation of their coupling with other degrees of freedom such as phonons. The frequency spectrum of phonons excited by second-order coupling with plasmons and the respective energy loss to the lattice are calculated, using a simple two-fluid-model and the Lagrangian formalism as appropriate for high coherent excitations.