  The relation of particle transport of relativistic particles in plasmas with
high-amplitude isotropic sub-Larmor-scale magnetic turbulence to the spectra of
radiation simultaneously produced by these particles is investigated both
analytically and numerically. We have found that in the asymptotic regime of
very small particle deflections the pitch angle diffusion coefficient is
directly related to the spectrum of the emitted radiation. Moreover, this
spectrum provides much information about the statistical properties of the
underlying magnetic turbulence. The transition from small- to large-scale
jitter to synchrotron radiation regimes as a function of turbulence properties
has also been explored. These results can readily be used to diagnose
laboratory and astrophysical plasmas.
