X-rays, radiation from

RESEARCH OF DEPENDENCE OF INTENSITY OF X-RAY RADIATION FROM PHYSICAL AND CHEMICAL PROPERTIES OF THIN-FILM SPECIMENS... 

At X-ray fluorescence analysis (XRF) of samples of the limited weight is perspective to prepare for specimens as polymeric films on a basis of methylcellulose [1]. By the example of definition of heavy metals in film specimens have studied dependence of intensity of X-ray radiation from their chemical compound, surface density (P ) and the size (D) particles of the powder introduced to polymer. Have theoretically established, that the basic source of an error of results XRF is dependence of intensity (F) analytical lines of determined elements from a specimen. Thus the best account of variations P provides a method of the internal standard at change P from 2 up to 6 mg/sm the coefficient of variation describing an error of definition Mo, Zn, Cu, Co, Fe and Mn in a method of the direct external standard, reaches 40 %, and at use of a method of the internal standard (an element of comparison Ga) value does not exceed 2,2 %. Experiment within the limits of a casual error (V changes from 2,9 up to 7,4 %) has confirmed theoretical conclusions. 

X-ray detectors also come in several varieties (1) single-photon counters which yield accurate results but require up to several weeks to acquire the 10,000 -100,000 (lO lO ) reflections necessary to compile a complete data set for a protein crystal (2) image plates that operate much like photographic film but are 10 times more sensitive (3) area detectors, electronic devices that detect X-ray photons on a two-dimensional surface. Both fluorescent-type detectors, image plates and fast area detectors, are more sensitive at the shorter wavelengths of X-ray radiation from synchrotron sources. 

In this study, in order to better understand the fundamentals of the laser-cluster interaction, we have carried out systematic investigations of the properties of X-ray radiation from high-density and high-temperature cluster plasma created by the action of superintense laser irradiation. The interrelationship between the X-ray radiation properties and ion kinetic energies has been examined for the first time via simultaneous measurements of X-ray radiation spectra and ion energy spectra. The time scale and mechanism of the X-ray emission process are discussed here based on a time-dependent plasma kinetics model. Moreover, in order to demonstrate the practical capabilities of the X-rays thus produced, pulse X-ray diffraction from an Si crystal using this source has been examined. 

Figure 7 C(ls) (right panel) and Of I. v) (left panel) XPS spectra for a freshly condensed layer of TDF (ca. 5 nm thick) on Ag(poly) at 130 K before (curves 1) and after (curves 2) exposure to X-ray radiation from a Mg source for 2.5 h. Curves 3 show the corresponding XPS spectra obtained for the X-ray exposed specimen after it had been warmed up to room temperature using hot nitrogen. (From Ref. 3.)...

Figure 2.1 X-ray tube structure. X-ray radiation from the anode is guided by the windows of the tube to produce an X-ray beam for diffraction.

Figure 6.18 XRF spectrum of a Pb alloy with primary X-ray radiation from the X-ray tube with a Rh target. The Rh characteristic lines are not overlapped with those of elements in the alloy specimen.

Figure 7.6 Non-monochromatic X-ray radiation from an X-ray gun with an A1 target. The characteristic Alkaline is at about 1.5 keV. (Reproduced with permission from D. Briggs and J.T. Grant, Surface Analysis by Auger and X-ray Photoelectron Spectroscopy, IM Publications and Surface Spectra Ltd, Chichester. 2003 IM Publications.)...

Fig. 14. Experimental set-up for the generation of ultra-short broadband hard X-ray radiation (From Ref. [67]).

Diffraction and reflection of x-ray radiation from atomic layers... 

W.T. Silfvast, J.J. Macklin, O.R. Wood II High-gain inner-shell photoionization laser in Cd vapor pumped by soft X-ray radiation from a laser produced plasma source. Opt. Lett. 8, 551 (1983)... 

A. Sjogren, M. Harbst, C.-G. Wahlstrom, S. Svanberg, C. Olsson High-repetition-rate, hard x-ray radiation from a laser-produced plasma Photon yield and application considerations. Rev. Sci. Instr, 74, 2300 (2003)... 

The spectrometer used to measure the VUV reflectivity spectrum has been described in detail elsewhere [20]. A continuum of VUV and soft X-ray radiation from a laser induced plasma source is focussed onto the polymer film, and the light reflected from the film dispersed by a 1 meter polychromator onto a optical multichannel analyzer. The... 

In this chapter we will focus on X-ray diffraction processes for the analysis of materials. XRD is sensitive to crystalline phases down to 0.1-1 wt%. Conventional XRD instruments use monochromatic (that is, with a well defined wavelength) X-ray radiation from Cu, Cr, Mo or Ag sources. Cm, in particular with the K-a line... 

Stribeck N. Sapoundijewa D, Denchev Z, Apostolov A A, Zachman H G, Stamm M and Fakirov S (1997) Deformation behavior of poly(ether ester) copolymer as revealed by small-and wide-angle scattering of X-ray radiation from synchrotron. Macromolecules 30 1329-1339. 

Fakirov S, Samokovlijsky O, Stribeck N, Apostolov A A, Denchev Z, Sapoundjieva D, Evstatiev M, Meyer A and Stamm M (2001) Nanostructnral Deformation Behavior in Poly (ethylene terephthalate)/Polyethylene Drawn Blend as revealed by Small Angle Scattering of X-Ray Radiation from Synchrotron Macromolecules 34 3314-3317. 

X-ray fluorescence (XRF) spectroscopy (characterization) The generation of characteristic X-ray radiation from a surface by bombarding the surface with X-rays. The emitted characteristic X-rays are characterized by their wavelength or energy. The analytical technique is a non-destructive technique for determining element composition of a layer up to several microns in thickness, depending on the mass of the elements. See also Micro X-ray analysis. 

X-ray photoelectron spectroscopy (XPS or ESCA) analyses were carried out on a PHI-TFA XPS spectrometer (Physical Electronics Inc). The analyzed area was 0.4 mm in diameter and about 3-5 nm in depth. This high surface sensitivity is a general characteristic of the XPS method. Sample surfaces were excited by X-ray radiation from a monochromatic Al source at a photon energy of 1486.6 eV. C Is, F Is, 0 Is, N Is and Si 2p spectra were acquired with an energy resolution of about 1.0 eV with an analyzer pass energy of 58 eV. Quantification of surface composition was performed from XPS peak intensities measured on three different spots of the sample, taking into account the relative sensitivity factors provided by the instrument manufacturer (Moulder, 1995). 

Figure 9.8 Generation of scattered light/X-ray radiation from an electron.

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