Elementary Statistical Models for Vector Collision-Sequence Interference Effects with Poisson-Distributed Collision Times

[摘要] 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 completelyrandomized in each collision. The distribution of velocities was assumed to be Gaussian. Theintegrated induced dipole momentμk, for vector interference, or the scalar modulationμk, for scalarinterference, was assumed to be a function of the impulse (integrated force)fk, or its magnitudefk, experienced by the molecule in a collision. For most of (Lewis,2008) it was assumed thatμk∝fkandμk∝fk, but it proved to be possible to extend the models, so that the magnitude of theinduced 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 induceddipole moment and force. One particular such model, using data from (Herman and Lewis,2006), leads to the most realisticestimate 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 thepresent 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.

[学科分类] 光谱学