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The use of a special device that limits the field of view of a detector, i.e., a confocal collimator, is one of the approaches to obtaining information about the spatial distribution of the detected material in the methods for radionuclide diagnostics (in medicine) and X-ray fluorescence analysis (in material science). This device is a monolithic construction with a large number of straight channels whose axes are directed towards a single point that is the focus of the confocal collimator. The possibility of fabricating confocal collimators using 3D printing technology is demonstrated. The advantages of 3D printing are simplicity, reliability, and wide availability. It is shown that the use of a confocal collimator in radionuclide diagnostics instead of a single-channel collimator is advantageous, since it substantially increases the sensitivity (by 2−7 times) with the simultaneous improvement of the resolution (approximately by 9 times). The applicability of the confocal collimator for determining the depth of occurrence of a radiation source, i.e., for measuring the three-dimensional distribution of the emitting (fluorescent) substance, is also demonstrated. [ABSTRACT FROM AUTHOR]

The possibility of localizing clusters of heavy atoms is substantiated by comparing the data of X-ray microtomography at different wavelengths, scanning electron microscopy, and X-ray fluorescence analysis. The proximal tail vertebrae of Turner's thick-toed gecko ( Chondrodactylus turneri) have been investigated for the first time by both histological and physical methods, including X-ray microtomography at different wavelengths and elemental analysis. This complex methodology of study made it possible to reveal the regions of accumulation of heavy elements in the aforementioned bones of Turner's thick-toed gecko. [ABSTRACT FROM AUTHOR]

The response signal collection functions in a confocal setup of the X-ray fluorescence (XRF) tomography have been modeled for a polycapillary collimator and a multichannel collimator fabricated by means of microelectronic technology (MT). The dimensions of the effective collection region for the two types of collimators are compared. For the MT-fabricated device, a fraction of X-ray photons transmitted due to the total external reflection from channel walls has been evaluated. It is shown that, for a proper choice of parameters, the contribution of these photons to the collection function is negligibly small. [ABSTRACT FROM AUTHOR]

Abstract: Recently, there has been a renewed interest for fluorescence spectroscopy, as provided by modern setups which allow 2D and 3D imaging of elemental distributions. Two directions are currently under development: the SR-based fluorescence tomography in polar scanning geometry, provided by the new generation of X-ray microprobes and the confocal scanning geometry, which can be fielded in both SR and laboratory environments. The new probes bring forth a new age in fluorescence spectrometry: high resolution, high intensity and high sensitivity which allow 3D elemental mapping of volumes. The major task now is the development of these complex tools into fully quantitative probes, reproducible and straightforward for general use. In this work we analyze two X-ray fluorescence microtomography techniques: an apparatus tomography using a confocal collimator for the data collection and a standard first generation Computed Tomography (CT) in the parallel scanning scheme. We calculate the deposited dose (amount of energy deposited and distributed in the sample during the data collection time) and find the conditions for the choice of the tomography scheme. [Copyright &y& Elsevier]

The capabilities and limitations of wavelet analysis are demonstrated for the illustrative case of two practial applications: investigation of magneto-tunneling signals and the extended x-ray absorption fine structure (EXAFS) of uranium. A brief introduction to wavelet analysis is given. The term “window size” of the mother wavelet function is defined; this concept underlies one of the ideas for a criterion of optimal choice of the mother wavelet function. The capabilities of a software package developed by the authors are demonstrated; this software was used for all the calculations done in the course of this study. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Presents a study which described the application of x-ray fluorescence microtomography on the ID22 undulator beamline at ESRF in Grenoble, France to homogeneous samples. Experimental setup on the ID22 beamline; Interaction process of the beam with the sample; Result of scanning the phantom in front of the beam.