An investigation of Atom Probe machine parameters on spectral resolution suggested that the traditional model for additive errors did not fully explain the changes in peak shape due to experimental settings. We propose a new hypothesis that explains the effects seen in the spectra and provides additional information about the chemical bonding of the material under examination. Our model requires that a thermal vibration of critical momentum and a photon

of sufficient energy must coincide at a single lattice point to provide an evaporation. Using equations derived from this hypothesis, we demonstrate the utility of this approach, which provides additional information about the process of evaporation using an Atom Probe.