This report studies the feasibility of using X-ray Fluorescence for the characterization of alpha sources in a short time and proposes a new Rule of Thumb for the sake of simplicity. An uranium deposit of 0.012 0.001 mg cm−2 which XRF spectrum shows a low intensity U-L peak at 13.61 keV, provides good resolution in alpha spectrometry. By this method, long data acquisition times in alpha spectrometry of poorly prepared sources are avoided without the need for expensive equipment.