  We demonstrate with a RF-MOT the one dimensional, transverse magneto-optical
compression of a cold beam of calcium monofluoride (CaF). By continually
alternating the magnetic field direction and laser polarizations of the
magneto-optical trap, a photon scattering rate of $2\pi \times$0.4 MHz is
achieved. A 3D model for this RF-MOT, validated by agreement with data,
predicts a 3D RF-MOT capture velocity for CaF of 5 m/s.
