Kinetic energy measurements of both positive and negative ions emitted from several alkali halides and their mixtures are reported. The measurements were conducted using the energy cut-off property of the ion mirror of a reflector type 252Cf plasma
desorption mass spectrometer. The results obtained indicate that some fraction of the
desorbed ions emitted under 252Cf bombardment have a kinetic energy deficit compared to die ions which gain full kinetic energy during the acceleration-region. The initial kinetic
energy of a particular ion was found to be rather independent upon the sample composition.
