Multiple-scattering events

In the central panel we show a measured energy spectrum near zero momentum compared with the LMTO calculation and the LMTO calculation plus simulation of multiple scattering events. 

Image formation in a transmission electron microscope can be considered as a two-step process. In the first step, the electron beam is interacting with the specimen. This interaction is very strong compared to X-ray or neutron scattering and causes multiple scattering events. In order to understand this process, the classical particle description of the electron is not adequate, and the quantum mechanical wave formalism has to be used. Thus, assuming the... 

Fig. 1. X-ray absorption spectrum (XAS) of Cu—Zn metallothionein at the Cu and Zn K-edges. The structure near the edge, referred to as XANES is dominated by multiple scattering events while the extended structure, referred to as EXAFS, at photoelectron energies greater than 30-50 eV is primarily due to single scattering events...

The thickness of sample cell holders is optimally given by the reciprocal of the absorption coefficient. While the scattered intensity increases linearly with thickness, the sample absorption, however, increases exponentially. The scattered intensity reaches its maximum value when the incident beam is weakened to /e = 0.37, and this means that 1 mm thick samples are usual in X-ray and neutron work in H2O buffers. For neutron work in H20 buffers, 2 mm thick samples are usual, even though the optimal thickness is now greater than 10 mm. Samples that are too thick may lead to curve artefacts from multiple scattering events. Allowance for... 

There should be some caution in broadly applying (9.1) to all types of carrier transport at interfaces. For example, the relationship does not accurately model the transit time of ballistic transport because the calculation of Xt depends on the mobility, which is only accurate in so far as it measures a diffusive process, i.e., one that involves multiple scattering events [9]. Because the small polaron conductors have transport mediated by lattice vibrations, numerous scattering events will occur as the carriers cross the space charge layer. Therefore, the transit times as calculated by (9.1) should be representative of the behavior for this class of materials [10]. 

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