Quantitative X-Ray Measurements of Diesel Spray Cores

2001 ◽  
Author(s):  
Christopher F. Powell ◽  
Yong Yue ◽  
Jin Wang ◽  
Ming-Chia Lai ◽  
Johannes Schaller
Keyword(s):  
Volume Fraction ◽  
Combustion Process ◽  
Argonne National Laboratory ◽  
Pollutant Emissions ◽  
Detailed Knowledge ◽  
X Rays ◽  
Time Resolved ◽  
X Ray ◽  
Fuel Sprays ◽  
Quantitative Measurements

Abstract A detailed knowledge of the fuel injection process is recognized as a key to the design of clean-burning and efficient combustion engines. As standards for pollutant emissions are tightened worldwide, such knowledge becomes more critical. Computer modeling of the combustion process relies on accurate measurements of the spray throughout its lifetime, and in particular knowledge of the near-nozzle region of the spray is of great importance. A number of techniques have been developed to study the properties of fuel sprays. However, all of these techniques are significantly limited in the region near the nozzle of high-pressure sprays. No mechanical or visible light probe is able to make non-intrusive and quantitative measurements of the spray in this region. We have been developing techniques to study sprays using synchrotron x-rays from the Advanced Photon Source at Argonne National Laboratory. We are using an intense, monochromatic x-ray beam as a probe to make time-resolved, quantitative measurements, of intermittent fuel sprays. These experiments have demonstrated that x-rays overcome many of the limitations of other techniques, allowing quantitative characterization of the spray with high time and position resolution. The x-ray technique enables us to make a time-resolved mapping of the mass distribution near the spray nozzle, even immediately adjacent to the orifice. With such a mapping of the mass a number of spray characteristics can be determined, such as the fuel volume fraction, the injection rate and total mass, the speed of the leading and trailing edges of the spray, etc. These quantitative measurements should allow more realistic computational modeling of sprays with better predictive power.

Synchrotron X-Ray Measurement of Direct Injection Gasoline Fuel Sprays

2001 ◽  
Author(s):  
Y. Yue ◽  
C. Powell ◽  
R. Cuenca ◽  
R. Poola ◽  
J. Wang
Keyword(s):  
Visible Light ◽  
Volume Fraction ◽  
Direct Injection ◽  
X Rays ◽  
Hollow Cone ◽  
Optical Techniques ◽  
Time Resolved ◽  
X Ray ◽  
Direct Measurements ◽  
Strong Asymmetry

Abstract A quantitative and time-resolved radiographic has been used to characterize direct-injection (Dl) gasoline sprays in near-nozzle region. The highly penetrative nature of x-rays promises the direct measurements of dense sprays that are difficult to study by visible-light optical techniques. Appropriate models were developed to determine the fuel volume fraction as a function of time and positions. The results also show quantitatively the strong asymmetry of the hollow-cone sprays studied here.

Mesoscopic structure of SiC fibers by neutron and x-ray scattering

1996 ◽  
Vol 11 (5) ◽  
pp. 1169-1178 ◽  
Author(s):  
Kentaro Suzuya ◽  
Michihiro Furusaka ◽  
Noboru Watanabe ◽  
Makoto Osawa ◽  
Kiyohito Okamura ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Volume Fraction ◽  
X Rays ◽  
X Ray ◽  
Sic Fibers ◽  
X Ray Scattering ◽  
Mesoscopic Structure ◽  
Angle Scattering ◽  
Momentum Transfer Range ◽  
First Time

Mesoscopic structures of SiC fibers produced from polycarbosilane by different methods were studied by diffraction and small-angle scattering of neutrons and x-rays. Microvoids of a size of 4–10 Å in diameter have been observed for the first time by neutron scattering in a medium momentum transfer range (Q = 0.1–1.0 Å−1). The size and the volume fraction of β–SiC particles were determined for fibers prepared at different heat-treatment temperatures. The results show that wide-angle neutron scattering measurements are especially useful for the study of the mesoscopic structure of multicomponent materials.

Structural dynamics of PZT thin films at the nanoscale

2005 ◽  
Vol 902 ◽  
Author(s):  
Alexei Grigoriev ◽  
Dal-Hyun Do ◽  
Dong Min Kim ◽  
Chang-Beom Eom ◽  
Bernhard Adams ◽  
...  
Keyword(s):  
Crystal Lattice ◽  
Lattice Distortion ◽  
Piezoelectric Effect ◽  
Polarization Switching ◽  
X Rays ◽  
Time Resolved ◽  
X Ray ◽  
Converse Piezoelectric Effect ◽  
Ferroelectric Capacitors ◽  
Crystal Lattice Distortion

AbstractWhen an electric field is applied to a ferroelectric the crystal lattice spacing changes as a result of the converse piezoelectric effect. Although the piezoelectric effect and polarization switching have been investigated for decades there has been no direct nanosecond-scale visualization of these phenomena in solid crystalline ferroelectrics. Synchrotron x-rays allow the polarization switching and the crystal lattice distortion to be visualized in space and time on scales of hundreds of nanometers and hundreds of picoseconds using ultrafast x-ray microdiffraction. Here we report the polarization switching visualization and polarization domain wall velocities for Pb(Zr0.45Ti0.55)O3 thin film ferroelectric capacitors studied by time-resolved x-ray microdiffraction.

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.

First X-Ray Microprobe and Microspectroscopy Results From The Gsecars Sector At The Advanced Photon Source

1997 ◽  
Vol 3 (S2) ◽  
pp. 905-906
Author(s):  
Mark L. Rivers ◽  
Stephen R. Sutton ◽  
Peter Eng ◽  
Matthew Newville
Keyword(s):  
National Laboratory ◽  
Argonne National Laboratory ◽  
Third Generation ◽  
X Rays ◽  
Environmental Sciences ◽  
X Ray ◽  
State Determination ◽  
X Ray Absorption ◽  
The Magnetic Field ◽  
Photon Source

The Advanced Photon Source (APS) at Argonne National Laboratory is a third-generation synchrotron x-ray source, optimized for producing x-rays from undulators. Such undulator sources provide extremely bright, quasi-monochromatic radiation which is ideal for an x-ray microprobe. Such microprobes can be used for trace element quantification with x-ray fluorescence, or for chemical state determination with x-ray absorption spectroscopy. The GeoSoilEnviroCARS (GSECARS) sector at the APS is building an x-ray microprobe for research in earth, planetary, soil and environmental sciences.The GSECARS undulator source is a standard APS Undulator “A” which is a 3.3 cm period device with 72 periods. The energies of the undulator peaks can be varied by adjusting the gap, and hence the magnetic field of the undulator. The energy of the first harmonic can be varied in this way from approximately 3.1 keV to 14 keV. A measured undulator spectrum is shown in Figure 1.

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.

scholarly journals Time-Resolved Macromolecular Crystallography at Pulsed X-ray Sources

2019 ◽  
Vol 20 (6) ◽  
pp. 1401 ◽  
Author(s):  
Marius Schmidt
Keyword(s):  
Structural Biology ◽  
Free Electron ◽  
Reaction Dynamics ◽  
X Rays ◽  
Free Electron Lasers ◽  
Macromolecular Crystallography ◽  
Time Resolved ◽  
X Ray ◽  
Methodological Aspects

The focus of structural biology is shifting from the determination of static structures to the investigation of dynamical aspects of macromolecular function. With time-resolved macromolecular crystallography (TRX), intermediates that form and decay during the macromolecular reaction can be investigated, as well as their reaction dynamics. Time-resolved crystallographic methods were initially developed at synchrotrons. However, about a decade ago, extremely brilliant, femtosecond-pulsed X-ray sources, the free electron lasers for hard X-rays, became available to a wider community. TRX is now possible with femtosecond temporal resolution. This review provides an overview of methodological aspects of TRX, and at the same time, aims to outline the frontiers of this method at modern pulsed X-ray sources.

scholarly journals Experimental and numerical study of ultra-short laser-produced collimated Cu Kα X-ray source

2017 ◽  
Vol 35 (3) ◽  
pp. 442-449 ◽  
Author(s):  
R. Rathore ◽  
V. Arora ◽  
H. Singhal ◽  
T. Mandal ◽  
J.A. Chakera ◽  
...  
Keyword(s):  
Laser Intensity ◽  
Numerical Study ◽  
Low Cost ◽  
Laser Pulses ◽  
Photon Flux ◽  
X Rays ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Short Laser Pulses

AbstractKα X-ray sources generated from the interaction of ultra-short laser pulses with solids are compact and low-cost source of ultra-short quasi-monochromatic X-rays compared with synchrotron radiation source. Development of collimated ultra-short Kα X-ray source by the interaction of 45 fs Ti:sapphire laser pulse with Cu wire target is presented in this paper. A study of the Kα source with laser parameters such as energy and pulse duration was carried out. The observed Kα X-ray photon flux was ~2.7 × 108 photons/shot at the laser intensity of ~2.8 × 1017 W cm−2. A model was developed to analyze the observed results. The Kα radiation was coupled to a polycapillary collimator to generate a collimated low divergence (0.8 mrad) X-ray beam. Such sources are useful for time-resolved X-ray diffraction and imaging studies.

Time-Resolved X-ray Shadowgraphy Experiment of Laser Ablation of Aluminum using Laser-Induced Picosecond Pulsed X-rays

1999 ◽  
Vol 38 (Part 2, No. 3A) ◽  
pp. L242-L244 ◽  
Author(s):  
Yoichiro Hironaka ◽  
Tomoharu Inoue ◽  
Yasushi Fujimoto ◽  
Kazutaka G. Nakamura ◽  
Ken-ichi Kondo ◽  
...  
Keyword(s):  
Laser Ablation ◽  
X Rays ◽  
Time Resolved ◽  
X Ray

scholarly journals Measurements of the ablation-front trajectory and low-mode nonuniformity in direct-drive implosions using x-ray self-emission shadowgraphy

2015 ◽  
Vol 3 ◽  
Author(s):  
D.T. Michel ◽  
A.K. Davis ◽  
W. Armstrong ◽  
R. Bahr ◽  
R. Epstein ◽  
...  
Keyword(s):  
Plasma Phys ◽  
X Rays ◽  
Direct Drive ◽  
Time Resolved ◽  
X Ray ◽  
Laser Facility ◽  
Omega Laser ◽  
Control Fusion ◽  
Pm 10 ◽  
Ablation Front

Self-emission x-ray shadowgraphy provides a method to measure the ablation-front trajectory and low-mode nonuniformity of a target imploded by directly illuminating a fusion capsule with laser beams. The technique uses time-resolved images of soft x-rays ( ${>}1$  keV) emitted from the coronal plasma of the target imaged onto an x-ray framing camera to determine the position of the ablation front. Methods used to accurately measure the ablation-front radius ( ${\it\delta}R=\pm 1.15~{\rm\mu}\text{m}$ ), image-to-image timing ( ${\it\delta}({\rm\Delta}t)=\pm 2.5$  ps) and absolute timing ( ${\it\delta}t=\pm 10$  ps) are presented. Angular averaging of the images provides an average radius measurement of ${\it\delta}(R_{\text{av}})=\pm 0.15~{\rm\mu}\text{m}$ and an error in velocity of ${\it\delta}V/V=\pm 3\%$ . This technique was applied on the Omega Laser Facility [Boehly et al., Opt. Commun. 133, 495 (1997)] and the National Ignition Facility [Campbell and Hogan, Plasma Phys. Control. Fusion 41, B39 (1999)].

Sign in / Sign up

Export Citation Format

Share Document