Angular-spectral distribution and polarization of synchrotron radiation from a "short" magnet

Power per unit solid angle, spectrum and polarization as a function of angle, and integrated spectrum are calculated for the radiation from a beam of ultrarelativistic ($\ensuremath{\gamma}\ensuremath{\gg}1$) charged particles in a magnet causing a deflection much smaller than $\frac{\mathrm{I}}{\ensuremath{\gamma}}$, with an arbitrary form of the magnetic field $B(z)$. Some examples are given, and the connection with the "edge effect" is shown.