Can Free Particles in Plasmas Have a Continuous Absorption Spectrum?

[Bob S]

(Posted by Dickfore:)
So, how are they free if they are in the vicinity of atoms?

Free as in not bound to a nucleus. Conduction band electrons in a condensed dielectric for example.

The difference between the photoelectric effect, in which the photon's total energy is absorbed by the electron, and Thomson scattering on free electrons, is that a little recoil momentum is absorbed by the recoiling atom or atomic lattice. Conduction electrons are not free electrons; the work function to remove a conduction electron is >= 3 eV.

Bob S