Inelastic scattering angular distribution

Theoretical work on inhomogeneous molecular distributions is as yet incomplete, but McNulty et al 6) have made some calculations on adsorbed molecules on the surface of particles. Their conclusion was that the angular distributions have structure and that the inelastic scattering intensity in the forward and backward directions is particularly sensitive to particle size. 

Chew and Wang(39) have pointed out the possibility of double resonance, that is, that the frequencies of both the excitation and inelastically scattered radiation are resonant. They presented the results of calculations which indicate that double resonance can have a significant effect on the angular intensity distribution of inelastically scattered radiation. This case is of some practical interest, particularly in Raman studies, where coincidence may lead to anomalous Raman band intensities, if both the excitation and the shifted frequency are resonant. 

The action of a circularly polarised pulse leads to a repopulation of electrons and holes between states with a different angular momentum component in the direction of the pump pulse wave vector. The corresponding SIFE relaxation time describes the recovery of the symmetry of the initial angular momentum distribution. Again it is preferable that the probe response is dominated by intraband transitions or else inelastic scattering may obscure the relaxation of hot electron (hole) angular momentum. 

The underlying background of secondary electrons exhibits no CDAD. These electrons have been inelastically scattered several times and lost their prior angular distribution. Not only the oxygen feature but also the rare earth metal valence bands show different photoelectron intensities indicating that CDAD effects do also arise for thin films and bulk material, respectively. 

Fig. 38 a and b. Angular distribution of 9.5 MeV protons scattered by neon, (a) Elastic group (b) inelastic group... 

---