scholarly journals Quantitative Measurements of X-Ray Intensity

10.5772/18261 ◽  
2011 ◽  
Author(s):  
Michael J. ◽  
Marilyn Schneider
Keyword(s):  
X Ray ◽  
Quantitative Measurements

Measurement of Biodiesel Blend and Conventional Diesel Spray Structure Using X-Ray Radiography

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
A. L. Kastengren ◽  
C. F. Powell ◽  
K.-S. Im ◽  
Y.-J. Wang ◽  
J. Wang
Keyword(s):  
Cone Angle ◽  
Injection Pressure ◽  
Fuel Distribution ◽  
X Ray ◽  
Spray Structure ◽  
Quantitative Measurements ◽  
Biodiesel Blend ◽  
Temporal And Spatial ◽  
Nozzle Geometries ◽  
Fuel Effects

The near-nozzle structure of several nonevaporating biodiesel-blend sprays has been studied using X-ray radiography. Radiography allows quantitative measurements of the fuel distribution in sprays to be made with high temporal and spatial resolution. Measurements have been made at different values of injection pressure, ambient density, and with two different nozzle geometries to understand the influences of these parameters on the spray structure of the biodiesel blend. These measurements have been compared with corresponding measurements of Viscor, a diesel calibration fluid, to demonstrate the fuel effects on the spray structure. Generally, the biodiesel-blend spray has a similar structure to the spray of Viscor. For the nonhydroground nozzle used in this study, the biodiesel-blend spray has a slightly slower penetration into the ambient gas than the Viscor spray. The cone angle of the biodiesel-blend spray is generally smaller than that of the Viscor spray, indicating that the biodiesel-blend spray is denser than the Viscor spray. For the hydroground nozzle, both fuels produce sprays with initially wide cone angles that transition to narrow sprays during the steady-state portion of the injection event. These variations in cone angle with time occur later for the biodiesel-blend spray than for the Viscor spray, indicating that the dynamics of the injector needle as it opens are somewhat different for the two fuels.

scholarly journals On the ionization of light gases by X-rays. I.—Technique

1933 ◽  
Vol 141 (845) ◽  
pp. 669-686
Keyword(s):  
Absolute Intensity ◽  
X Rays ◽  
X Ray ◽  
Quantitative Correlation ◽  
Quantitative Measurements ◽  
Fluorescent Radiation ◽  
A New Technique ◽  
Heavy Gas ◽  
Reliable Correlation

The measurement of the intensity of an X-ray beam in absolute units is in theory most satisfactorily accomplished by a determination of its heating effect. The method, however, is attended by considerable experimental difficulties, so that its application is very limited, and in practice it is usual to replace it by a determination of the ionization produced when the beam is passed through a gas. To correlate the ionization with an absolute intensity requires a quantitative knowledge of the details of the interaction between the X-rays and the molecules concerned and of the ionization of the gas by the ejected electrons. It sometimes happens that the processes involved about which we know least are relatively unimportant, so that a fairly reliable correlation can be made; and much work has been done on the application of the ionization method to X-ray dosimetry. But in general a quantitative correlation between ionization and intensity is not possible. A further study of the ionization of gases by X-rays is therefore desirable; moreover it may be made to yield important information concerning the processes involved. The early development of the physics of X-rays contains many examples of this, and more recently an important contribution has been made by Stockmeyer. The events leading to the ionization of a heavy gas are exceedingly complicated, whereas in the light gases (hydrogen and helium) some of these events are absent or else occur to a negligible extent, so that the interpretation of experiments with the latter becomes simpler and more reliable. These gases are therefore specially worthy of study. Moreover, for them the application of quantum mechanics leads to the most definite results for comparison with experiment, and in particular permits of a direct test of some aspects of Dirac’s theory of recoil scattering. The ionization due to the gas itself is, however, very small, and may even be less than the secondary ionization due to electrons liberated from the chamber walls. The technique used in ionization measurements with heavy gases is therefore unsuitable. Hitherto the only attempt made to extend such measurements to light gases is an experiment carried out in 1915 on hydrogen by Shearer who, however, obtained very variable results and an ionization markedly smaller than that to be expected from recoil electrons alone. Moreover his experimental method is now open to criticism in view of our greater knowledge of X-rays, and in particular the fluorescent radiation used was of doubtful homogeneity. The present paper will describe a new technique suitable for quantitative measurements of the ionization produced by X-rays in light gases, and in another paper it will be applied to a re-investigation of hydrogen.

Proton-Induced X-ray Emission Analysis of Human Autopsy Tissues

1976 ◽  
Vol 20 ◽  
pp. 403-410
Author(s):  
R. D. Lear ◽  
H. A. Van Rinsvelt ◽  
W. S. Adams
Keyword(s):  
Trace Element Analysis ◽  
Human Kidney ◽  
Essential Elements ◽  
Element Analysis ◽  
Emission Analysis ◽  
University Of Florida ◽  
X Ray ◽  
Quantitative Measurements ◽  
Autopsy Tissues ◽  
The University

The 3.8 MeV proton beam from the University of Florida Van de Graaff accelerator has been used to perform trace element analysis of approximately 1200 samples (mostly from autopsies) of human tissues by proton-induced X-ray emission analysis (PIXE). Fifteen different organs and a variety of diseases have been studied. Preliminary data are presented indicating the variations of various elements in human kidney as a function of age. Analysis of samples from infants also indicate essential and non-essential elements in human kidney. On the average twelve trace elements (with atomic number equal to or larger than nineteen) are observed in each organ. Quantitative measurements have been made on several elements including K, Ca, Mn, Fe, Cu, Zn, Pb, Br, Rb, Sr, Cd, and Ba.

scholarly journals Quantitative measurements using soft x-ray streak cameras

1981 ◽  
Author(s):  
Robert L. Kauffman ◽  
Gary L. Stradling ◽  
Edward L. Pierce ◽  
Hector Medecki
Keyword(s):  
X Ray ◽  
Quantitative Measurements

Application of a Polarized X-Ray Spectrometer for Analysis of Ash from a Refuse-Fired Steam Generating Facility

1983 ◽  
Vol 27 ◽  
pp. 519-526
Author(s):  
William E. Maddox
Keyword(s):  
Air Force ◽  
Bottom Ash ◽  
X Rays ◽  
Double Scattering ◽  
Scattering Process ◽  
X Ray ◽  
Quantitative Measurements ◽  
Langley Research Center ◽  
Fluorescence Spectrometer ◽  
The City

AbstractThe Refuse-Fired Steam Generating Facility (RFSGF) funded jointly by NASA, the U.S. Air Force, and the City of Hampton is presently in operation at the NASA/Langley Research Center in Hampton, Virginia. The facility b u m s approximately 200 tons/day of refuse and supplies approximately 170x103 tons/year of steam at 350 psig to the Langley Center. Concentrations of trace elements in the bottom ash and in the ash from the electrostatic precipitators were determined using the Murray State Polarized X-Ray Fluorescence Spectrometer (PXFS), The PXFS uses x-rays from a Phillips PW1140/96 x-ray generator in a double scattering process to make quantitative measurements on elements in pressed briquette samples. The double scattering process is used to produce polarized x-rays for excitation of the samples, Minimum detectable limits (MDL) of 1-3 ppm are achieved for elements with Z = 26 to 42. Lower Z elements have significantly higher MDL's; the lowest Z element detected, sulfur, has an MDL of 100 ppm. Elements with Z's higher than 42 have MDL's in the range of 4-10 ppm. Elements detected in the RFSGF ash were S, Cl, K, Ca, Ti, V, Mn, Fe, Cu, Zn, Br, Rb, Sr, Zr, Sn, Sb, and Pb. The concentrations ranged from a few ppm to several mg/g.

Compositional and Texture Analysis of Tantalum Thin Films by Energy Dispersive X-Ray Analysis

1973 ◽  
Vol 27 (2) ◽  
pp. 99-102 ◽  
Author(s):  
H. S. deBen ◽  
Barret Broyde
Keyword(s):  
Thin Films ◽  
Texture Analysis ◽  
Diffraction Method ◽  
Preferred Orientation ◽  
Energy Dispersive ◽  
X Ray ◽  
Quantitative Measurements

Quantitative measurements of concentrations are given for the phases present in undoped tantalum thin films by the use of energy-dispersive x-ray detectors. This diffraction method can also yield the extent of preferred orientation.

A furnace and environmental cell for thein situinvestigation of molten salt electrolysis using high-energy X-ray diffraction

2011 ◽  
Vol 19 (1) ◽  
pp. 39-47 ◽  
Author(s):  
Mark J. Styles ◽  
Matthew R. Rowles ◽  
Ian C. Madsen ◽  
Katherine McGregor ◽  
Andrew J. Urban ◽  
...  
Keyword(s):  
Molten Salt ◽  
Inert Anode ◽  
High Energy ◽  
X Ray Diffraction ◽  
Molten Salt Electrolysis ◽  
X Ray ◽  
Quantitative Measurements ◽  
Materials Used ◽  
Characterization Of Materials

This paper describes the design, construction and implementation of a relatively large controlled-atmosphere cell and furnace arrangement. The purpose of this equipment is to facilitate thein situcharacterization of materials used in molten salt electrowinning cells, using high-energy X-ray scattering techniques such as synchrotron-based energy-dispersive X-ray diffraction. The applicability of this equipment is demonstrated by quantitative measurements of the phase composition of a model inert anode material, which were taken during anin situstudy of an operational Fray–Farthing–Chen Cambridge electrowinning cell, featuring molten CaCl2as the electrolyte. The feasibility of adapting the cell design to investigate materials in other high-temperature environments is also discussed.

Design of an X-Ray Fluorescence Sensor for the Cone Penetrometer

1994 ◽  
Vol 38 ◽  
pp. 699-704
Author(s):  
W.T. Elam ◽  
J. Y. Gilfrich
Keyword(s):  
Detection Limits ◽  
Correction Method ◽  
Cone Penetrometer ◽  
X Ray ◽  
Fundamental Parameters ◽  
Quantitative Measurements ◽  
Regulatory Limits ◽  
Path Lengths ◽  
Ray Path ◽  
Certified Values

Abstract The cone penetrometer is a well-established method for exploring soil types whereby a smalldiameter pipe with a hardened cone tip is pushed hydraulically into the ground. The system can be equipped with sensors to detect soil contamination. We have investigated the development of an x-ray fluorescence (XRF) sensor to be deployed via this system. The principal uncertainties in the application of XRF to metals detection in the cone penetrometer are the detection limits and the accuracy of a sensor built in such a confined geometry. A laboratory mock-up was constructed to investigate the performance of such a sensor. An x-ray tube operated at very low power was coupled to an electrically cooled Si(Li) detector. The x-ray path lengths were kept short and an aperture and incident x-ray filter similar to those appropriate for a penetrometer sensor were used. Spectra were collected on a series of Standard Reference Material soils from the National Institute of Standards and Technology consisting of soils with various levels of metal contamination. The detection limits were determined for the metals present in the soils and were comparable to the solid waste regulatory limits. Quantitative measurements were compared to the NIST certified values both without matrix correction and using the fundamental parameters correction method. Results were generally within 10% of the certified values.

Application of Calculated Intensities for Reflection X-ray Topographs

1970 ◽  
Vol 14 ◽  
pp. 163-172
Author(s):  
R. C. Blish
Keyword(s):  
Penetration Depth ◽  
X Ray ◽  
Quantitative Measurements ◽  
Fluorescent Screen

AbstractThis paper is an effort to quantify such variables as penetration depth, intensity, and defect contrast in reflection X-ray topographs. The analysis includes an appropriate combination of geometrical, polarization, absorption, and scattering factors. Quantitative measurements have been made for a variety of diffracting planes and-wavelengths on Si and Ge. The calculations also fit qualitatively (fluorescent screen intensity} with observations on Zn, ZnO, CdS, GaAs, GaP. Topographs from some or all of these materials will be shown to illustrate how these calculations can predict useful diffraction conditions.

Sign in / Sign up

Export Citation Format

Share Document