  Magnetized high-energy-density plasmas can often have strong electromagnetic
fluctuations whose correlation scale is smaller than the electron Larmor
radius. Radiation from the electrons in such plasmas, which markedly differs
from both synchrotron and cyclotron radiation, and their energy and pitch-angle
diffusion are tightly related. In this paper, we present a comprehensive
theoretical and numerical study of the particles' transport in both cold,
"small-scale" Langmuir and Whistler-mode turbulence and its relation to the
spectra of radiation simultaneously produced by these particles. We emphasize
that this relation is a superb diagnostic tool of laboratory, astrophysical,
interplanetary, and solar plasmas with a mean magnetic field and strong
small-scale turbulence.
