Scattering rainbow

Rainbow scattering has been detected from high Miller Index stepped platinum surfaces. Typical rainbow scattering patterns are shown in Fig. 4.7. The increase in intensity of the surface rainbows, as displayed by this figure, for an increase in the angle of incidence, qualitatively follows the trend predicted from calculations by McClure... 

Fig. 4.5. Schematic atomic scattering distributions for (a) specular scattering, (b) rainbow scattering and (c) diffraction...

The position, rs, of the repulsive structure increases for heavier partners. This point is less certain since, as usual for rainbow scattering, the experimental maxima correlate strongly with the energy of the structure in the potential, only weakly with its range. 

Kleyn, A.W. and Horn, T.C.M. (1991). Rainbow scattering from solid surfaces, Physics Reports 199, 191-230. 

For systems with larger values of aR, rainbow scattering may be completely quenched [2, 15,41,42]. This occurs, for example, in K. + Br2 and K + CBr4. The long-range potential parameters must then be calculated in a different manner [15], based on the supposition that the reaction has a zero threshold energy, so that elastic scattering occurs only from the portion... 

Fig. 3. Part of the deflection function which is responsible for rainbow scattering. The shaded area determines the positions of the rainbow oscillations which are caused by the interference of trajectories around b2 and b3.

The measurable quantities are then calculated with the help of these functions. For instance, the rainbow scattering is given by Equation (16). Because of the behaviour of Af and the smaller amplitude of the second term, the positions of the supernumerary rainbows zN are given by the zeros of A lzN) (maxima) and the zeros of A,(zN) (minima). Now zN is calculated using (19) and the function (48) with the result... 

Figure 3.1 Rainbow scattering of heavy atoms from an ordered surface...

The moleculai beam experiments on rainbow scattering are rather expensive. Therefore the efficiency of the gas-surface interaction is described frequently in terms of the exchange coefficients of momentum... 

Rainbow scattering and the quantum mechanical interference of different trajectories... 

---