Scattering, collision-induced

L. Frommhold, K. H. Hong, and M. H. Proffitt. Collision-induced scattering of light by Ar pairs. Molec. Phys., 35 665, 1978. 

Le Duff Y (1979) Collision-induced scattering in helium. Phys Rev A 20 48-53... 

F. Barocchi and M. Zoppi. Determination of collision induced polarizability in Ar, Kr, and Xe by means of collision induced scattering Analysis and empirical pair potentials. J. Chem. Phys., (57 901-905 (1976). 

A. Barreau, J. Berrue, A. Chave, B. Dumon, and M. Thibeau. Spectrum of collision induced scattering Role of multipolar polarizabilities. Optics Communic., 55 99-104 (1985). 

A. Gharbi and Y. Le Duff. Many-body correlations for Raman and Rayleigh collision induced scattering. Molec. Phys., 40 545-552 (1980). 

Y. Le Duff and A. Gharbi. Collision induced scattering at a vibrational Raman frequency. Phys. Rev. A, 77 1729-1734 (1978). 

B. Hegemann and J. Jonas. Reorientational motion, collision induced scattering, and vibrational relaxation in liquid carbonyl sulfide. J. Chem. Phys., 79 4683-4693 (1983). 

It has been shown that multipolar polarizabilities contribute significantly to the collision-induced scattering from fluids composed of linear (N2, CO2) or... 

As noted above, experimental measurements must be very carefully performed. All measurements must be extrapolated to infinite dilution. In addition, care should be taken to subtract collision-induced scattering from the data, especially for the shorter chain molecules (see Chapter 14). For larger molecules extrapolation to zero q must be done in order to avoid intramolecular interference effects. Local field effects must also be considered when relating the experimental depolarized intensities to <(y2)>. 

Much remains to be done in this area. The role of the many-body polarizability has yet to be explored, a simple dynamical model has yet to be presented, and a microscopic justification of Eq. (14.2.5) has yet to be developed. Moreover the important practical question concerning the collision-induced scattering from molecular liquids has yet to be answered. Only after this effect is assessed can it be subtracted from the depolarized scattering in such a manner that the remaining spectrum gives information about molecular tumbling. 

Crand for a scattering angle "Q" = 90° then = 0. Generally this is not the case because either the moTecules or their arrangement are not optically isotropic or the scattering mechanism is not (collision induced scattering). Under these conditions we observe the depolarized spectrum lyu. In this case we have for optically inactive molecules ly = ijjy. 

Frommhold, L. (1981). Collision-induced scattering of light and the diatom polarizabilities. Adv. Chem. Phys. 46, 1. 

---