Mass of an ion in the spectrometer

In a mass spectrometer ions of charge $e$, starting practically at rest, are accelerated by the potential difference $\Delta V=1.0\mathrm{kV}$ and enter a uniform magnetic field $B=0.20\mathrm{T}$ perpendicular to the velocity, where they describe a semicircle of radius $r=12.0\mathrm{cm}$. Compute the mass of the ions in kilograms and in atomic mass units ($1\mathrm{u}=1.66\cdot 10^{-27}\mathrm{kg}$).