In a recent paper (Lewis, 2008) a class of models suitable for application to collision-sequence interference was introduced. In these models velocities are assumed to be completely
randomized in each collision. The distribution of velocities was assumed to be Gaussian. The
integrated induced dipole moment μk, for vector interference, or the scalar modulation μk, for scalar
interference, was assumed to be a function of the impulse (integrated force) fk, or its magnitude
fk, experienced by the molecule in a collision. For most of (Lewis, 2008) it was assumed that μk∝fk and μk∝fk, but it proved to be possible to extend the models, so that the magnitude of the
induced dipole moment is equal to an arbitrary power or sum of powers of the intermolecular force.
This allows estimates of the infilling of the interference dip by the disproportionality of the induced
dipole moment and force. One particular such model, using data from (Herman and Lewis, 2006), leads to the most realistic
estimate for the infilling of the vector interference dip yet obtained.
In (Lewis, 2008) the drastic assumption was made that collision times occurred at equal intervals. In the
present paper that assumption is removed: the collision times are taken to form a Poisson process.
This is much more realistic than the equal-intervals assumption.
The interference dip is found to be a Lorentzian in this model.