We study quantum radiation generated by the accelerated motion of a small b
ody with a refractive index n which differs slightly from 1. To simplify ca
lculations we consider a model with a scaler massless field. We use the per
turbation expansion in a small parameter n - 1 to obtain a correction to th
e vacuum Hadamard function for a uniformly accelerated motion of the body.
We obtain the vacuum expectation for the energy density flux in the wave zo
ne and discuss its properties.