Scatter Profiles Research Articles

Effects Of Scattering On X-Ray Imaging

Very high spatial frequency irregularities with small amplitude on a polished surface that usually cause wide-angle scattering in conventional optical systems produce narrow-angle scattering in x-ray systems. Yet, even this small amount of scattering degrades the imaging properties of x-ray systems. Statistical surface perturbations and their effects on x-ray image quality are discussed. A model of surface roughness that is reasonably consistent with surface profile measurements and visible scatter profile measurement is discussed. This model is then used to evaluate the image profile of an x-ray system.

Small-angle X-ray study of microdomains in rigid PVC

PVC samples prepared under various conditions have been examined by small-angle X-ray scattering (SAXS) in the region greater than 5 milliradians. The intensity of the scatter is consistent with a two phase structure of crystallites in an amorphous matrix. The scatter profile from the original powder and from mouldings that have not been annealed fits a Debye exponential correlation function. This suggests nodular crystallites of wide size distribution with typical diameters of 3 nm. Mouldings that have been annealed give scattering profiles with a broad peak, whose maximum corresponds to an equivalent Bragg period of about 10 nm. Probably after annealing the nodular crystallites have become more uniform in size and are arranged more regularly.

Separation of leukemic myeloblasts and splenic lymphocytes based upon differences in light scatter profile

Cell sorting based upon differences in light scatter profile was carried out to sort cells which differ in size. This technique permitted the acquisition of subpopulations of murine spleen cells enriched for leukemic myeloblasts or lymphocytes. Morphologic assessment of the sorted populations was confirmed by malignancy assay in vivo . The same technique has been applied to human leukemic cells and significant enrichment for proliferating and quiescent cells was accomplished.

On the relation between the daytime deep scattering layer and the temperature field at Ocean Acre

At Ocean Acre, the volume backscatter strength S(z;f), 12–15.5 kHz, associated with the daytime deep scattering layer in the main thermocline region is due to backscattering from swimbladder fish. In the NDI model for S(z;f) developed previously for light-sensitive layers, it is assumed that the number density n(z) of “effective scatterers” is determined by a Gaussian distribution of “preferred” light intensity values I tracked by the scatterers. that I decays with depth according to Lambert's law, and that the average backscatter cross section δ(z;f) is a constant, δ(f). This model is found to describe the daytime deep scatterer profile S only if I is replaced by an analogous “preferred” variable I′ with an exponential decay rate approximately one-tenth the extinction coefficient for light. Thus, some other environmental factor than light intensity primarily determines the shape of the S-profile for this layer. Here a physical interpretation of the NDI′ model is developed by showing that (1) measured abundance profiles nb(z) of swimbladder fish in the daytime deep scattering layer are described by the NDI′ model and (2), the exponentially decaying I′ required by the model is obtained if I′ is identified with a simple logarithmic function of the temperature field.

A Study of the Relationship Between Geometry and Light Scattering Profiles of Single Wool Fibers

A study of relationship between fiber geometry and the light scattering profiles of single wool fibers, obtained by drawing the fibers through a light beam and continuously recording the far field interference pattern, has shown that the spacing of the first minimum in the profile can be closely related to the fiber diameter via the Fraunhofer far field diffraction equation for an opaque strap.

An Analysis of the (002) X-ray Scattering Profile of Carbon by an Electronic Computer

An Analysis of the (002) X-ray Scattering Profile of Carbon by an Electronic Computer

Comparison of total electron contents from Beacon satellite Faraday rotation measurements and simultaneous incoherent scatter profiles

Total electron contents obtained by the differential Faraday method during 26 near-overhead passes of the Beacon-B satellite at Aberystwyth are compared with the results of integrating vertical N( h) profiles observed simultaneously by the incoherent scatter radar at Malvern, 117 km to the east. In 19 cases agreement within the experimental errors was found with a standard method of analysis of the satellite data, using a constant value of the magnetic field function M ̄ ; in three cases agreement could be reached only by allowing for an unsuspected ambiguity of π radians in the measured differential rotation angle; in two cases when the F2-peak was abnormally high it was necessary to adjust M ̄ ; in one case the presence of strong waves made the comparison invalid, and in one case there was a significant unexplained discrepancy. Computation of the mean Faraday height, h F , for the 26 incoherent scatter profiles showed that h F is roughly proportional to the F2 peak height, h max , and that ( h F— h max ) has a mean value of about 80 km. There is some indication that the use of the normal first order expression for the total Faraday rotation leads to overestimation of electron content: this problem can be dealt with by an empirical modification of the standard analysis.

Simultaneous measurements of electronic density using topside soundings and incoherent scatter soundings

Electron density measurements obtained from ISIS satellite topside soundings are compared with incoherent scatter measurements at St. Santin. The data are critically analysed. Most of the topside profiles agree with incoherent scatter profiles. Some of them which disagree are discussed and it is concluded to be due to oblique propagation.

G.P.ゾーンを含むアルミニウム合金におけるX線小角散乱プロフィルの解析と粒子サイズ分布

G.P.ゾーンを含むアルミニウム合金におけるX線小角散乱プロフィルの解析と粒子サイズ分布