Neutron techniques

Table 1.1 summarises the characteristics. Electron microscopy and diffraction and X-ray topography and diffraction are complementary techniques in almost every respect. The neutron techniques have applications similar to X-rays but decisive advantages in some cases, such as the study of magnetic materials and of very thick samples. The theory is well rmderstood for all three. Two great... 

Neutron techniques are based on the detection of the nuclear properties of possible threats rather than their density or chemical properties. One may summarize the advantages of these techniques as follows ... 

Due to several factors that have been discussed, using neutron techniques for transportable systems for the detection of explosives and other contraband remains only a goal at this time. The attraction of using neutrons lies in both their penetrating ability and the ability to use them to detect elemental composition. These properties are unique to neutron-based systems and have led to continued interest in their use, and multiple systems have been investigated as can be seen in Table 1 [44], At the present time, the use of neutron techniques as a complement to other inspection methods appears to be the most likely near-term mode of operation. 

Table 1. Summary of neutron techniques currently being investigated [44]. 

The book includes several chapters on vapor and trace detection chemiluminescence, mass spectrometry, ion mobility spectrometry, electrochemical methods, and micro mechanical sensors, such as microcantilevers. Other chapters deal with bulk detection techniques neutron techniques, nuclear quadrupole resonance, X-ray diffraction imaging, millimeter-wave imaging, terahertz imaging, and laser techniques. Special chapters are devoted to personnel portals and to biological detection. 

The feasibility of adopting neutron diffraction to measure RS in welded joints, on the other hand, is largely shown by various experiments carried out in different neutron sources. The adoption of neutron techniques enables also ... 

In both cases, sample size was found to be a crucial parameter. As we have seen in Section XII. A, growing very large crystals of organic conductors is not easy. To make the experiment feasible one can think of a bunch of carefully aligned smaller crystals and/or take advantage of improvements in polarized neutron techniques since the 1980s. 

A special field of application of these techniques is the determination of molecular conformations in cases where X-ray and neutron techniques are not applicable, in solution or in the liquid phase. It is known that conformers afford essentially the same spectra the intensities of some bands may vary. It is sufficient to investigate some bands in order to determine the conformation, and quantum chemical methods can be applied (Oelichmann et al., 1981a, b, 1982 Grunenberg and Bougeard, 1987). 

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