Gamma ray absorption

Storm, E., Gilbert, E., Israel, H. In Gamma-Ray Absorption Coefficients for Elements 1 Through 100, Los Alamos Scientific Laboratory LA-2237. University of California, New Mexico (1958)... 

Mossbauer spectroscopy involves the measurement of minute frequency shifts in the resonant gamma-ray absorption cross-section of a target nucleus (most commonly Fe occasionally Sn, Au, and a few others) embedded in a solid material. Because Mossbauer spectroscopy directly probes the chemical properties of the target nucleus, it is ideally suited to studies of complex materials and Fe-poor solid solutions. Mossbauer studies are commonly used to infer properties like oxidation states and coordination number at the site occupied by the target atom (Flawthome 1988). Mossbauer-based fractionation models are based on an extension of Equations (4) and (5) (Bigeleisen and Mayer 1947), which relate a to either sums of squares of vibrational frequencies or a sum of force constants. In the Polyakov (1997)... 

Foam densities were determined by use of gamma ray absorption to determine the amount of crude carried over in the foam. Under severe conditions, foam densities between 15.6 and 33.7 Ibm/cu ft (250 and 540 kg/m3 were measured, compared with a crude density of 50 6 Ibm cu 4 ft (810 kg. m11 Thus the crude content of the loam was between 28 and 66% by volume. Furthermore, up to 900 tonnes/hr (900 Mg/h], or 50%, of the crude fed to a separator could be carried over in foam Profiles of foam density and carry-over were similar for both the HP and LP separators. 

Microwave-based meters have also been used to monitor water content in emulsions (39). Microwave techniques can be used in two ways Either the attenuation of the microwave radiation due to absorption by the water phase is measured, or capacitance or resonance changes in a microwave cavity are noted. The capacitance-change method is much more sensitive, although both, like the gamma-ray absorption method, are limited in that solids content must be constant or zero in order to accurately interpret the information obtained. Both of these techniques are applicable to field situations and on-line monitoring. 

The p-process is one of proton capture (p,y) or of gamma-ray absorption with neutron emission (y,n), and is responsible for many proton-rich nuclides of low abundance, generally derived from iron-group elements. Finally, an x-process is responsible for the synthesis of D, Li, Be and B which are unstable at the temperatures reached inside stars, where they are converted to helium by a large number of processes including 2D(p.y) He, Li(p,a) He and iiB(p,a)8Be -> 2 He. 

I crguson, H., and W.R.Gardner. 1963. Diffusion theory applied to water flow data obtained using gamma ray absorption. Soil Sci. Soc. Am. Proc. 27 243-246... 

Gamma-ray methods have been used to measure solids concentration in slurry pipelines. Usually, the gamma-ray source and detector are mounted in the opposite sides of the pipe as shown in Figure 22. It should be mentioned that the gamma-ray absorption method in this case will measure solids concentration averaged over a chord in the pipe. It is worth noting that the chord-average concentration can be different from local solids concentration in some applications. Examples of such... 

Gamma-ray absorption occurs as illustrated in Figure 6.16 by four different processes coherent scattering, photoelectric effect, Compton effect, and pair production. For each of these processes, a partial coefficient can be expressed ... 

Moteff, J. Tenth-value Thicknesses for Gamma-ray Absorption, Nucleonics, 13(7) 24 (1956). 

Using nucleonic level detectors These usually employ gamma ray absorption or neutron backscatter techniques, but may also use gamma ray backscatter (Sec. 14.5). A case where a gamma ray absorption indicator solved a level control problem at the base of a column has been described (71). 

The base level controllo failed at startup, and liquid level in the coliunn rose to fill half the column. This caused excessive heavies in the top product, possib due to liquid carryover. The problem was diagnosed using ganuna scans. Cutting feed rate provided shortterm solution. Using a gamma-ray absorption level indicator provided a longer-term solution. 

The heat load in the reflector arising from gamma-ray absorption. 

The gamma -ray absorption measurements were made in the rectangular, assembly having core dimensions 71 by 17 by 66 cm and loaded to 2.94 kg of fuel. Measurements were made in the core and in the reflector along a line... 

The gamma-ray transmission technique previously employed by Vermeulen et al. (5) has been used to determine the point gas holdup in mechanically agitated tank by Calderbank, in plate columns and in packed columns (I). The principles of the application of gamma-ray absorption to holdup measurements depend on the use of the relationship. 

Mheemeed A. K. et al. Gamma-ray absorption using rubber lead mixtures as radiation protection shields. J. Radioanal Nucl Chem 2012, 291,653-659. 

Make corrections for gamma-ray absorption within the sample and/or between source and detector. 

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