We describe the design and performance of a slow atomsource based on a 2D magneto-optical trap (MOT) that uses aninnovative simple optical configuration. Metal-coatedretro-reflecting prisms replace mirrors and quarter-wave plates sothe optical power of the cooling laser beam is recycled. Thissource has been characterised for three different configurations:with and without transverse magnetic field gradient, and with apusher beam to obtain a 2D+-MOT. The longitudinal velocity isof the order of 25 m·s−1, with a transverse velocityspread ≤1 m·s−1, while the typical atomic fluxdensity obtained is up to1.3×1014 at ·s−1·m−2 for a cesiumvapour pressure of ~4×10−8 mbar in the source. Weuse this slow atom beam, instead of cesium vapour, to load a 3Dmoving optical molasses that feeds a continuous cold atomfountain. We obtain a gain of a factor ~20 in the atomicflux launched by the fountain.