Wavelength, isotopic shift, and transition rate of the MgI resonance line

The isotopic shifts and the wavelength of the magnesium resonance line 1S0-1P1 at 285.2 nm were measured in an atomic beam by using an intracavity frequency doubled dye laser. The absolute wavelength was obtained by using the absorption I2 spectrum at the laser fundamental as a reference. The comparison with the existing data evidences an error in some largely used wavenumber tables. The upper level lifetime was also obtained from the observed linewidth. (orig.)