Radiation production by and transport of non-relativistic particles in plasmas with sub-Larmor-scale magnetic fields

Plasma turbulence often has sub-Larmor-scale magnetic field fluctuations. Particle diffusion of and radiation production by ultra-relativistic particles has been explored earlier. In particular, it was shown that jitter radiation theory replaces synchrotron radiation one. The spectral characteristics and particle diffusion coefficient were shown to be intimately related. Here we extend these results to non-relativistic particles. In particular, we are interested in spectral characteristic of the emitted radiation. We show that such radiation is drastically different from cyclotron radiation, which is applicable only for nearly homogeneous fields but fails if the field correlation scale is smaller than the particle's Larmor radius. These results can be very valuable for remote diagnostics of laboratory and astrophysical plasmas.