Back-scatter technique

Consequently, we will follow the example of Mills et al. (29) who recently presented the first measurements of local solvent concentration using the Rutherford back-scattering technique. They analyzed the case of 1,1,1-trichloroethane (TCE) diffusing into PMMA films in terms of a simpler model developed by Peterlin 130-311, in which the propagating solvent front is preceded by a Fickian precursor. The Peterlin model describes the front end of the steady state SCP as ... 

McConnell, J.A. Smuck, W.W. Gamma back-scatter technique for level and density detection. Chem. Eng. Progr. 1967, 63 (8), 79-82. 

Back-scattering techniques that are suitable for measuring concentrated samples. 

Details of the Rutherford Back Scattering technique as applied to polyethylene have been described elsewhere (3). The IRS measurements were carried out using a Perkin Elmer 621 infrared spectrometer. A KRS-5 reflection element with dimensions 50 mm X 2 mm was used with a 45° angle of incidence. Further details can be found elsewhere (I). Most of the atomic absorption measurements were performed by the Fairfield Testing Laboratory, Fairfield, NJ. The x-ray fluorescence measurements were carried out on a GE-XRD6 spectrometer. 

Oblique ultrasonic waves sent to a composite at frequencies that excite plate wave modes induce the leaky lamb wave phenomenon. When the leaky Lamb wave is generated, the specular reflection is distorted. When the specular reflection and the leaky Lamb wave interfere, a phase cancellation occurs, and two components are generated with a phase between them. Because each type of defect has a unique response, this technique can be used to determine material eleastic constants and to estimate the volume content of resin as well as porosity content. Detection of transverse cracking and delamination in a 24-layer unidirectional graphite-epoxy laminate has also been reported [140], and oblique incidenee back-scattering techniques give accurate fiber orientation of the first composite layers [15],... 

Gamma and x back-scattering techniques are based upon the Compton photon back-scatter effect. Collimated low-energy gamma rays or X-rays are emitted and beamed at the inspected material. The rays become scattered back toward the detector in direct proportion to the mass of the material in front of the probe. A. scintillation cry.stal detector is used to convert the back-scattered protons into an electrical signal that can be related to material thickness, provided that the material density is constant. Back-scattered. x-rays can be detected by an ariay of scintillation detectors, and the position of the detector relative to the sample relates to different depths in that sample [84]. 

Detection of level and interface by neutron back-scattering technique... 

Ali MY, El-Megrab AM, Jonah SA, Su D, Varadi M, Csikai J (1995) Nucl Geophys 9 203 Aoki T, Baba M, Ibaraki M, Miura T (2000) Feasibility study on non-destructive analysis of light elements by fast neutron back-scattering technique, radiation detectors and their uses. In Sasaki S, Shibata T, Takahashi H, Nakazawa M (eds) KEK proceedings 2000-14, KEK, Japan, p 163... 

The transport of Ni through P-doped [100] monocrystalline wafers of Czochralski material was measured at 450 to 540C by using Rutherford back-scattering techniques. By assuming a cluster model for interstitial Ni, with substitutional P and perhaps O, it was deduced that the Ni diffusivity was described by ... 

Diffusion of Ag in pyrolytically deposited carbon was determined between 450 and 800C using a He back-scattering technique. The specimens were prepared as flat deposits on a plane surface. The Ag concentrations produced by implantation were calculated before and after diffusion heat treatments at constant temperatures using back-scattering spectra and allowing for evaporation at the surface. The results could be described by ... 

Sedimentation balances and (3 back-scattering techniques have been used for the cumulative measurements while sampling (Andreasen pipette method) or the absorption of radiation (photosedimentation or use of X-rays) are most frequently used for the incremental measurements. It seems that the incremental techniques, because of their advantages of easy operation and evaluation, and relatively simple instrumentation, have somewhat wider application. 

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