1,720,993 research outputs found
Charged and Neutral Particles Channeling Phenomena: Channeling 2008 - Proceedings of the 51St Workshop of the Infn Eloisatron Project
No full textThe book "Channeling 2008", Charged and Neutral Particles Channeling Phenomena, is formed by the same title conference contributions. This volume includes papers by leading researchers from different world centers. Their recent results on the coherent phenomena of charged and neutral particles propagating through the structures of various sizes and periodicities are included here, along with historical reviews by pioneers of coherent Bremsstrahlung and channeling radiation as well as crystal channeling collimation
Channeling projects at LNF: from crystal undulators to capillary waveguides
No full textFrascati's National Laboratories (LNF INFN) are well known in the world for pioneering research in the particle interaction and synchrotron radiation physics fields. Good experience in designing accelerators, storage rings and beamlines for synchrotron radiation allows presently LNF to be in the frontier for the construction of new X-ray generation sources. This report is an introduction to new research activity "Coherent Scattering Phenomena for Radiations in Solids" started in Frascati within the approved projects SPARC, SPARX and PLASMON-X. The main purpose of the project is to develop research area for studying the channeling phenomena of charged and neutral particles in periodic solid structures
On X-Ray Channeling in a Vibrating Capillary
No full textA novel study on a different use of polycapillary optics is presented. The scope of this study is to achieve
an efficient radiation collimation due to handled beam profiling that avoids the typical one based on total
external reflection into the capillary channel. For this purpose a vibration is applied to a monocapillary in
order to emulate a ‘‘virtual roughness’’ on the channel internal wall surface. The transmission properties
of such a system for different vibrational states are discussed
RXR: a new X-Ray Facility at XLab-Frascati
No full textX-ray fluorescence analysis is a widely used technique in many applications. Recent advances in X-ray optics, in particular, in
polycapillary manufacturing, have allowed achieving microscale spatial resolution, even with conventional sources. Nowadays,
many apparatus for X-ray microfluorescence are available. But the majority of them are equipped with experimental chambers,
which limit their applicability only to small-sized samples. To overcome this limitation, a newinstrument named Rainbow
X-Ray (RXR), optimized for large and heavy objects, has been developed at XLab Frascati. Here, we present this unit dedicated
to 2D and 3D X-ray microspectroscopy (both mapping and ‘colour‘ tomography), with a resolution between 25 and 75 m,
depending from the incident energy in the range 800 eV–25 keV
Proposal for a prototype of portable μXRF spectrometer
No full textμXRF is a powerful instrument for non-destructive characterization of materials of cultural interest. At the XLab Frascati Laboratory this technique is already well performed thanks to the polyCO set equipment allowing simultaneous μXRF 2D mapping. However, due to the strict demand for in situ analysis in this particular field, a new portable μXRF spectrometer equipped with a full polycapillary lens conjugated with a transmission anode X-ray tube is proposed.
Many cultural objects are characterized by elements (Ag, Sn, etc.) with high energy fluorescence K-lines. Thus, the capability of a full lens to deliver a high energy fraction of X-ray spectrum, in order to excite the fluorescence K-lines of such elements, is tested
GDI spray structure analysis by polycapillary s-ray μ-tomography
No full textA X-ray l-tomography technique, using a Cu Ka source at 8.048 keV coupled with both polycapillary
optics and CCD detector, has been developed to reconstruct the composition of a transient gasoline spray
generated by a high-pressure GDI injector for automotive applications. The polycapillary elements enable
shaping the divergent beams and getting high-contrast images due to the suppression of radiation multiple
scattering. A pressure-tight device permits the 360 rotation of a six-hole nozzle, with a step of 0.1, at
injection pressures up to 20 MPa, while the spray plume develops in a vented Plexiglas chamber at the
atmospheric backpressure. The entire system is configured as a table-top experiment. The extinction
images acquired along the X-ray source-spray-detector line-of-sight have permitted the reconstruction
of a 3D structure together with a morphology of the jets within a 3 mm region downstream the nozzle.
The spray shape as well as the propagation direction can be clearly identified in the tomographic reconstruction
for all the six jets. Quantitative measurements of the fuel mass density in the near nozzle region
have been performed. Typical Gaussian-shape distribution of the intensities appears for the cross sections
revealing the more dense jet regions in the core, while slight longitudinal asymmetries indicate an interaction
between the jet plumes
XRF approach to non-destructive characterization of gilded and enamelled silver of cultural interest: the case study of some medieval religious objects from central Italy
No full text
3D structure of liquid sprays: x-ray μ-radiography and tomography by polycapillary based technique
No full textThis work reports the results of X-ray μ-tomographic investigation on the inner structure of high pressure fuel sprays. X-ray imaging is widely used in industry where non-destructive and high accuracy measurements of the samples morphology are required. A high flux beam can overcome the problems related to the low absorption of hydrocarbon chains as fossil fuels, therefore synchrotron X-ray sources are generally used for fuel sprays investigation.
A desktop facility has successfully been used to characterize high pressure gasoline sprays for automotive applications. A X-ray tube coupled with polycapillary optics has been used providing a high flux beam with low divergence. In this paper the last improvements concerning quantitative measurements carried out on fuel sprays are reported
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