scholarly journals Improving EDS For Low Energy X-Rays Under 1000eV Using an Attachable Detector Optic

2008 ◽  
Vol 16 (2) ◽  
pp. 6-9
Author(s):  
David O’Hara ◽  
Greg Brown ◽  
Eric Lochner
Keyword(s):  
Dead Time ◽  
Beam Current ◽  
High Energy ◽  
Low Energy ◽  
Detector Response ◽  
X Rays ◽  
Ray Optics ◽  
X Ray ◽  
Optics Fabrication ◽  
Made In

Although considerable advances have been made in Energy Dispersive Detectors for microanalysis, low energy analysis under 1000eV is still relatively poor due to detector response and inefficient production of low energy x-rays. X-ray optics fabrication methods by O’Hara and measurements by McCarthy et. al. indicated that it should be possible to fabricate x-ray optics that could be used to significantly increase the low energy x-ray flux seen by an EDS detector without increasing the beam current. Such an optic would be useful to increase low energy counts without moving the detector closer, which would simply increase the high energy counts and dead time.

Sky survey of high-energy cosmic X-rays and spectral information on sources in the Crab nebula, Cygnus, and Scorpius

1968 ◽  
Vol 46 (10) ◽  
pp. S409-S413 ◽  
Author(s):  
Walter H. G. Lewin ◽  
George W. Clark ◽  
William B. Smith
Keyword(s):  
Crab Nebula ◽  
High Energy ◽  
X Rays ◽  
Coma Cluster ◽  
X Ray ◽  
Sky Survey ◽  
Upper Limits ◽  
Intensity Ratios ◽  
The Crab Nebula ◽  
Made In

A complete X-ray survey of the northern sky has been made in the energy range 20–100 keV. Spectra are given for Cyg X-1 and Tau X-1. Intensity ratios (Cyg X-1/Tau X-1) of 0.84 ± 0.10 and 1.30 ± 0.25 were derived in the 20–70 keV range from data obtained on July 19, 1966 and February 13, 1967, respectively. Observations on Sco X-1 and the Coma cluster show upper limits which are quite different from results reported by other groups.

KAONIC HELIUM MEASUREMENTS IN THE SIDDHARTA EXPERIMENT

2011 ◽  
Vol 26 (03n04) ◽  
pp. 601-603
Author(s):  
◽  
D. L. SIRGHI ◽  
M. BAZZI ◽  
G. BEER ◽  
L. BOMBELLI ◽  
...  
Keyword(s):  
Energy Shift ◽  
High Energy ◽  
Low Energy ◽  
Kaonic Hydrogen ◽  
X Rays ◽  
X Ray ◽  
Kaonic Deuterium ◽  
Theoretical Predictions ◽  
First Time ◽  
Hadronic Atom

The SIDDHARTA experiment (SIlicon Drift Detector for Hadronic Atom Research by Timing Application) had the aim to perform kaonic atoms X-ray transitions measurements, to better understand aspects of the low-energy QCD in the strangeness sector. The experiment combined the excellent low-energy kaon beam generated at DAΦNE, allowing to use gaseous targets, with excellent fast X-rays detectors: Silicon Drift Detectors. SIDDHARTA was installed on DAΦNE in autumn 2008 and took data till late 2009. Apart of the kaonic hydrogen and kaonic deuterium measurements, we have performed the kaonic helium transitions to the 2p level ( L -lines) measurements: for the first time in a gaseous target for helium4 and for the first time ever for kaonic helium3. The interest for such type of measurement was rather high, being it triggered by two reasons: the so-called "kaonic helium puzzle" (even if this was solved by KEK-PS E570 experiment, but a cross-check was useful) and some theoretical predictions of possible high energy shift (at the level of 10 eV). In this paper the preliminary results for the measurements to the 2p level ( L -series) for kaonic helium4 and kaonic helium3 are presented.

Oxford HEXameter: Laboratory High Energy X-Ray Diffractometer for Bulk Residual Stress Analysis

2006 ◽  
Vol 524-525 ◽  
pp. 743-748 ◽  
Author(s):  
Alexander M. Korsunsky ◽  
Shu Yan Zhang ◽  
Daniele Dini ◽  
Willem J.J. Vorster ◽  
Jian Liu
Keyword(s):  
Accurate Determination ◽  
High Energy ◽  
Energy Dispersive ◽  
Detector Response ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Instrument ◽  
Synchrotron Beamlines

Diffraction of penetrating radiation such as neutrons or high energy X-rays provides a powerful non-destructive method for the evaluation of residual stresses in engineering components. In particular, strain scanning using synchrotron energy-dispersive X-ray diffraction has been shown to offer a fast and highly spatially resolving measurement technique. Synchrotron beamlines provide best available instruments in terms of flux and low beam divergence, and hence spatial and measurement resolution and data collection rate. However, despite the rapidly growing number of facilities becoming available in Europe and across the world, access to synchrotron beamlines for routine industrial and research use remains regulated, comparatively slow and expensive. A laboratory high energy X-ray diffractometer for bulk residual strain evaluation (HEXameter) has been developed and built at Oxford University. It uses a twin-detector setup first proposed by one of the authors in the energy dispersive X-ray diffraction mode and allows simultaneous determination of macroscopic and microscopic strains in two mutually orthogonal directions that lie approximately within the plane normal to the incident beam. A careful procedure for detector response calibration is used in order to facilitate accurate determination of lattice parameters by pattern refinement. The results of HEXameter measurements are compared with synchrotron X-ray data for several samples e.g. made from a titanium alloy and a particulate composite with an aluminium alloy matrix. Experimental results are found to be consistent with synchrotron measurements and strain resolution close to 2×10-4 is routinely achieved by the new instrument.

Polycapillary X-ray optics for microdiffraction

1999 ◽  
Vol 32 (2) ◽  
pp. 160-167 ◽  
Author(s):  
C. A. MacDonald ◽  
S. M. Owens ◽  
W. M. Gibson
Keyword(s):  
Line Emission ◽  
High Energy ◽  
Small Sample ◽  
Quality Data ◽  
Characteristic Line ◽  
X Rays ◽  
Glass Capillary ◽  
Data Set ◽  
Ray Optics ◽  
X Ray

Polycapillary optics,i.e.shaped arrays consisting of hundreds of thousands of hollow glass capillary tubes, can be used to redirect, collimate or focus X-ray beams. X-rays emitted over a large angular range from conventional laboratory-based sources can be transformed into a beam with a small angular divergence or focused onto a small sample or sample area. Convergent beams of X-rays, with convergence angles as high as 15°, have been produced using polycapillary X-ray optics. Focused-spot sizes as small as 20 µm have been achieved, with flux densities two orders of magnitude larger than that produced by pinhole collimation. This results in a comparable decrease in data collection times because of the increase in direct-beam intensity and reciprocal-space coverage. In addition, the optics can be employed to reduce background and provide more convenient alignment geometries. The inverse dependence of the critical angle for total external reflection on photon energy results in suppression of high-energy photons. This effect can be employed to allow the use of higher tube potentials to increase the characteristic line emission and has also been employed to increase significantly theKα/Kβ ratio in Cu radiation. Measurements of X-ray diffraction data and crystallographic analyses have been performed for systems ranging from elemental crystals to proteins. Data from a lysozyme protein `standard' with a slightly convergent beam, taken in 3 min per frame with 2° oscillation with a 2.8 kW source, refined to an intensity variance of 5% compared to a standard data set. High-quality data were also obtained with a 0.03 kW fixed-anode source and a 2° convergent lens in 5 min per frame.

Characterization and interpretation of the quantum efficiencies of multilayer semiconductor detectors using a new theory

1998 ◽  
Vol 5 (3) ◽  
pp. 877-879
Author(s):  
T. Cho ◽  
M. Hirata ◽  
J. Kohagura ◽  
Y. Sakamoto ◽  
T. Okamura ◽  
...  
Keyword(s):  
Heavy Particle ◽  
Current Mode ◽  
High Energy ◽  
Detector Response ◽  
Semiconductor Detectors ◽  
X Rays ◽  
Fusion Plasma ◽  
X Ray ◽  
New Type ◽  
High Bias

On the basis of a new theory of semiconductor X-ray detector response, a new type of multilayer semiconductor detector was designed and developed for convenient energy analyses of intense incident X-ray flux in a cumulative-current mode. Another anticipated useful property of the developed detector is a drastic improvement in high-energy X-ray response ranging over several hundred eV. The formula for the quantum efficiency of multilayer semiconductor detectors and its physical interpretations are proposed and have been successfully verified by synchrotron radiation experiments at the Photon Factory. These detectors are useful for data analyses under strong radiation-field conditions, including fusion-plasma-emitting X-rays and energetic heavy-particle beams, without the use of high-bias applications.

THE DOPPLER FACTORS AT X-RAY BAND OF THE BLAZARS

2005 ◽  
Vol 14 (06) ◽  
pp. 947-956
Author(s):  
D. C. MEI ◽  
L. ZHANG
Keyword(s):  
Synchrotron Radiation ◽  
Energy Range ◽  
High Energy ◽  
Low Energy ◽  
X Rays ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Doppler Factor ◽  
Intrinsic Radiation

We study the Doppler factors for a group blazars at soft X-ray band. In our estimates, we have made the assumptions that (i) blazars can be divided into high-energy-peaked (HEP) objects whose synchrotron peak frequencies νp > 1014.7 Hz , and the low-energy-peaked (LEP) objects whose synchrotron peak frequencies νp≤1014.7 Hz , and (ii) the intrinsic radiation from a blazar in the energy range from radio to soft X-ray bands is the synchrotron radiation for HEP objects and the soft X-ray emission comes from inverse Compton scattering for LEP objects. Under the above assumptions, we estimate Doppler factors at optical (δO) and X-rays (δx) for 54 blazars by using the known radio Doppler factors and the observed flux densities in radio, optical and X-ray bands, and Doppler factors [Formula: see text] at X-ray band in which X-rays are assumed to be produced only by the synchrotron radiation. We get [Formula: see text] . The Doppler factors are different in various wavebands, and on average, the Doppler factor decreases with frequency from radio to X-ray bands.

scholarly journals Requirement of HE-PIXE at High Z Elements in Charnockite Matrix Composition

2020 ◽  
Author(s):  
Avupati Venkata Surya Satyanarayana ◽  
Mokka Jagannadha Rao ◽  
Byreddy Seetharami Reddy
Keyword(s):  
Gamma Rays ◽  
Analytical Techniques ◽  
High Energy ◽  
Low Energy ◽  
Matrix Composition ◽  
X Rays ◽  
X Ray ◽  
Analytical Technique ◽  
Analytical Tools ◽  
Ray Series

Abstract. The maximum of Proton Induced X-ray Emission analytical technique on metamorphic rocks in geology has used 3 MeV range proton beams for excitation of thick targets. Protons of such energies do not accurately excite K-X–rays for high Z elements in matrix geological compositions like charnockite. In this analysis, low-energy PIXE (LE-PIXE) uses K-X-rays of Low Z elements and L-X-ray series for high Z elements. The resulting spectra between K-X-rays of light elements and L-X-rays of heavy elements can require striping techniques to resolve overlap difficulties in matrix composition. The results high Z elements in charnockite are to be expected, as the cross section for K-shell ionization of high-Z elements have greater values in the proton energy range of greater than 3 MeV in case of charnockite matrix composition. It has been suggested that the overlap of these discrete, gamma-rays with the X-ray spectrum may be serious problem in charnockite high energy PIXE (HE-PIXE) work, sufficient to preclude its use as a viable analytical technique. The conclusion proves that for a very complex matrix charnockite material of unknown chemistry, a HE-PIXE analytical spectrum may contain various X-ray and gamma peaks, some of which may overlap, making the analysis of line identities and the evaluation of X-ray counts intractable. It does not however represent any intrinsic drawback in HE-PIXE, nor does it mean that HE-PIXE is any more or less intractable than many other nuclear analytical techniques. Alternatively, the same analytical tool use could be made of gamma-rays in HE-PIXE as in low energy analytical tools like PIGE, NRA or INAA to obtain the results of charnockite at high Z completely.

Prospects for X-Ray Analysis of Rough Surfaces in the SEM

2000 ◽  
Vol 6 (S2) ◽  
pp. 918-919
Author(s):  
P.J. Statham
Keyword(s):  
Rough Surface ◽  
Beam Current ◽  
Low Energy ◽  
X Rays ◽  
X Ray ◽  
Beam Voltage ◽  
Gradual Loss ◽  
Characteristic Lines ◽  
Lower Beam ◽  
Key Aspects

Some of the key aspects affecting analysis of a rough surface are described in Fig. 1. If a hypothetical sample consisting of 96% Si, 1% O, 1% Na, 1% Al and 1% Fe is analysed at 20kV at constant beam current with an x-ray detector elevated at 30deg from horizontal then the measured intensities of the various characteristic lines will vary with tilt. While absorption of low energy x-rays is reduced as the sample tilts towards the detector, there is also a gradual loss of intensity due to increased backscatter. At the lower beam voltage of 5kV, absorption of x-rays at zero tilt is already small and Fig.2 shows that variation in intensity with positive tilts is substantially reduced, although absorption still becomes significant if the sample is tilted away from the detector.

The Energy Flow of X-Rays in Germanium Single Crystals

1973 ◽  
Vol 28 (5) ◽  
pp. 577-580
Author(s):  
L. Gerward
Keyword(s):  
Absorption Edge ◽  
Energy Flow ◽  
High Energy ◽  
Low Energy ◽  
X Rays ◽  
Angular Divergence ◽  
Wave Fields ◽  
X Ray ◽  
Set Up ◽  
Energy Side

The energy flow of the X-ray wave fields set up by diffraction in a germanium single crystal has been studied by shadow sharpness measurements. The shadow has been produced by an absorbing wire close to the X-ray entrance surface of the crystal. Intensity profiles have been observed in the wavelength range from 1.541 Å to 0.709 Å, including the K absorption edge of germanium at 1.117 Å. It is shown that the angular divergence of the energy flow is almost independent of the wavelength on each side of the absorption edge. The angular divergence is considerably reduced when passing the absorption edge from the low-energy side to the high-energy side, the thickness of the crystal being kept constant.

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