L Subshell Fluorescence Yields and Coster–Kronig Transition Rates at Z = 88 and 94

1974 ◽  
Vol 52 (6) ◽  
pp. 488-498 ◽  
Author(s):  
J. L. Campbell ◽  
L. A. McNelles ◽  
J. S. Geiger ◽  
R. L. Graham ◽  
J. S. Merritt
Keyword(s):  
Conversion Electron ◽  
Detection Efficiency ◽  
Transition Probability ◽  
X Rays ◽  
Transition Rates ◽  
Conversion Electrons ◽  
X Ray ◽  
Coincidence Measurements

The L2 and L3 subshell fluorescence yields, ω2 and ω3, and the Coster–Kronig transition probability f23 in 88Ra and 94Pu have been deduced from conversion electron L X-ray coincidence measurements. The Chalk River [Formula: see text]-spectrometer was used to select the conversion electrons. X rays were detected in a Si(Li) counter which was calibrated for absolute X-ray detection efficiency. The results are as follows: [Formula: see text]

scholarly journals Design and Performance of the X-ray Polarimeter X-Calibur

2014 ◽  
Vol 03 (02) ◽  
pp. 1440008 ◽  
Author(s):  
M. Beilicke ◽  
F. Kislat ◽  
A. Zajczyk ◽  
Q. Guo ◽  
R. Endsley ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Detection Efficiency ◽  
Grazing Incidence ◽  
High Energy ◽  
X Rays ◽  
Field Orientation ◽  
Synchrotron Source ◽  
X Ray ◽  
And Performance ◽  
Detector Assembly

X-ray polarimetry promises to give qualitatively new information about high-energy astrophysical sources, such as binary black hole systems, micro-quasars, active galactic nuclei, neutron stars, and gamma-ray bursts. We designed, built and tested a X-ray polarimeter, X-Calibur, to be used in the focal plane of the balloon-borne InFOCμS grazing incidence X-ray telescope. X-Calibur combines a low-Z scatterer with a Cadmium Zinc Telluride (CZT) detector assembly to measure the polarization of 20–80 keV X-rays making use of the fact that polarized photons scatter preferentially perpendicular to the electric field orientation. X-Calibur achieves a high detection efficiency of ≃80%. The X-Calibur detector assembly is completed, tested, and fully calibrated. The response to a polarized X-ray beam was measured successfully at the Cornell High Energy Synchrotron Source. This paper describes the design, calibration and performance of the X-Calibur polarimeter. In principle, a similar space-borne scattering polarimeter could operate over the broader 2–100 keV energy band.

Conversion-electron and gamma–gamma directional correlation measurements in 134Ba

1990 ◽  
Vol 68 (12) ◽  
pp. 1479-1485 ◽  
Author(s):  
Bakhshish Chand ◽  
Jatinder Goswamy ◽  
Devinder Mehta ◽  
Nirmal Singh ◽  
P. N. Trehan
Keyword(s):  
Conversion Electron ◽  
Hpge Detector ◽  
Transition Probability ◽  
Energy Levels ◽  
Electron Spectrometer ◽  
Conversion Electrons ◽  
Conversion Coefficients ◽  
First Time ◽  
Rotor Model

Conversion electrons from the decay of 134Cs have been investigated using a mini-orange electron spectrometer. The electron intensities for the K-conversion of 242.7 keV and L, (M + N … ) conversion of 563.2, 795.9, 801.9, 1038.6, 1167.9, and 1365.2 keV transitions in 134Ba are being reported for the first time. The conversion-electron data have been further used to determine the conversion coefficients for various transitions in, 34Ba. Also, the gamma–gamma directional correlation measurements for seven cascades in 134Ba have been carried out using a HPGe–HPGe detector coincidence setup. The multipole admixtures for the 475.3, 563.2, 569.3, 795.9, 801.9, 1038.6, and 1365.2 keV transitions have been deduced from these measurements. A multipole admixture of M1 + 37% E2 has been obtained for the 1038.6 keV transition in 134Ba. The reduced transition probability ratios for the transitions de-exciting second 2+ and 3+ energy levels in 134Ba have been calculated and compared with the values predicted by the triaxial rotor model for γ = 28.5°. This indicates the softness of the, 134Ba nucleus toward γ deformation.

M-SHELL X-RAY TRANSITION RATES FOR HEAVY RARE EARTH ELEMENTS

1998 ◽  
Vol 08 (04) ◽  
pp. 235-251
Author(s):  
K. SERA ◽  
K. ISHII ◽  
H. ORIHARA
Keyword(s):  
Cross Sections ◽  
Production Cross ◽  
X Rays ◽  
Transition Rates ◽  
Heavy Rare Earth ◽  
Crystal Spectrometer ◽  
Pixe Analysis ◽  
X Ray ◽  
Heavy Lanthanides ◽  
Heavy Rare Earth Elements

Partial M-x-ray production cross sections, which have not been well investigated up to the present, were measured in detail for six heavy lanthanides; Dy , Ho , Er , Tm , Yb and Lu . As a result, it is found that intensities of Mα,β lines, which are dominant among all the M-x-rays, and (M1-N2, M1-N3, M2-N4) lines agree well with those predicted by theory. However, clear discrepancy is found for Mζ and Mγ x-rays. Although it was pointed out by a PIXE analysis with a high-resolution crystal spectrometer that special attention must be paid for an analysis of Mζ and Mγ lines, it is found from the present work that it is possible to perform quantitative analysis using Mα,β lines.

scholarly journals Photoluminescence and scintillation characteristics of Bi-loaded PVK-based plastic scintillators for the high counting-rate measurement of high-energy X-rays

RSC Advances ◽  
2021 ◽  
Vol 11 (26) ◽  
pp. 15581-15589
Author(s):  
Atsushi Sato ◽  
Arisa Magi ◽  
Masanori Koshimizu ◽  
Yutaka Fujimoto ◽  
Shunji Kishimoto ◽  
...  
Keyword(s):  
Counting Rate ◽  
Detection Efficiency ◽  
Light Yield ◽  
High Energy ◽  
X Rays ◽  
Rate Measurement ◽  
High Counting Rate ◽  
X Ray ◽  
Plastic Scintillators

Bi-loaded PVK-based plastic scintillators doped with bis-MSB are applicable for high counting-rate measurement of high-energy X-rays. They showed a higher detection efficiency and light yield than EJ-256 under 67.41 keV X-ray irradiation.

Energy dispersive microprobe analysis of intracellular mineral deposits in rat bone

1978 ◽  
Vol 36 (2) ◽  
pp. 666-667
Author(s):  
D.W. Dempster ◽  
W.A.P. Nicholson ◽  
H.Y. Elder ◽  
D.A.S. Smith ◽  
R.P. Ferrier
Keyword(s):  
Microprobe Analysis ◽  
Detection Efficiency ◽  
Thin Foil ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
Small Areas ◽  
System A ◽  
Transmission Electron ◽  
Close Proximity

The use of an energy dispersive X-ray microanalytical system (EDX) attached to a conventional transmission electron microscope (TEM) allows images of good morphological resolution from ultra-thin specimens and spectra of all detectable elements to be obtained simultaneously at radiation doses which are low compared to wavelength dispersive detectors. For reasons of detection efficiency the solid angle subtended from the specimen to the detector is maximised (∼0.l sterad) in our system, a LINK SYSTEMS 290 with a 30mm2Si(Li) crystal fitted to a JEOL JEM lOOC. However, with this type of system the recorded spectrum has contributions not only from the small areas which can be probed but also from scattered electrons, and X-rays originating in the surrounding specimen, the specimen support system and the microscope environment of the specimen. The problem is particularly acute in projects, such as the present, where it is necessary to detect and determine the ratios of elements (Ca and P) in small quantities in close proximity to relatively massive concentrations of the same elements.Modifications to our system have been described (Nicholson et al., 1977a;Biddlecombe et al., 1977) which greatly improve the peak/background ratios for quantitative analysis and eliminate all of the specific peaks of non-specimen origin. For ease of maintenance the JEOL 100C is fitted with thin foil condenser apertures (10μm thick molybdenum) as standard. At the accelerating voltage used in this study (80 keV) a considerable number of electrons are transmitted by these apertures and with the electron probe placed adjacent to fully mineralized bone the scattered electrons were responsible for generation of sizeable Ca and P signals. We have replaced the standard foils with thick (0.25 mm) molybdenum apertures.

A Comparison of Detection Systems for Trace Phase Analysis

1984 ◽  
Vol 28 ◽  
pp. 361-365
Author(s):  
Stephen B. Robie ◽  
Thomas R. Scalzo
Keyword(s):  
Dead Time ◽  
Detection Efficiency ◽  
Total System ◽  
Semiconductor Detectors ◽  
X Rays ◽  
X Ray Diffraction ◽  
X Ray ◽  
Detection Systems ◽  
Sufficient Energy ◽  
Graphite Monochromator

Since the introduction of semiconductor detectors with sufficient energy resolution to resolve K-alpha X-rays from the K-beta X-rays for first row transition metals, there have been several attempts (1,2) to replace traditional detector systems (scintillation detector/graphite monochromator or proportional counter/nickel filter) in X-ray diffraction with semiconductor detectors. The goal of these experiments was to increase the total system detection efficiency by combining the K-beta discrimination and X-ray detection into a single operation. These early attempts showed that the semiconductor detector based system was more efficient, however, the problem of large dead-time losses hampered development in this area.

Recent Developments in Txrf of Light Elements

1995 ◽  
Vol 39 ◽  
pp. 771-779 ◽  
Author(s):  
Christina Streli ◽  
V. Bauer ◽  
P. Wobrauschek
Keyword(s):  
Absorption Edge ◽  
Detection Efficiency ◽  
Fluorescence Analysis ◽  
Total Reflection ◽  
Low Energy ◽  
X Rays ◽  
Light Elements ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Recent Developments

Total Reflection X-ray Fluorescence Analysis (TXRF) has been proved to be well suited for the energy dispersive analysis of light elements, as B, C, N, O, F, Na, Mg,.,. using a special spectrometer. It is equipped with a Ge(HP) detector offering a sufficient detection efficiency from 180 eV upwards. The obtainable detection limits especially of the light elements are mainly influenced by the excitation source, which should provide a large number of photons with an energy near the K-absorption edge of these elements (from 200 eV upwards). Commercially available X-ray tubes do not offer characteristic X-rays in that range. In former experiments a windowless X-ray tube was built to prevent the low energy X-rays from being attenuated in the Be window. Experiments have been performed using Cu as anode material.

scholarly journals Design of the Telescope Truss and Gondola for the Balloon-Borne X-ray Polarimeter X-Calibur

2017 ◽  
Vol 06 (02) ◽  
pp. 1740003 ◽  
Author(s):  
Fabian Kislat ◽  
Banafsheh Beheshtipour ◽  
Paul Dowkontt ◽  
Victor Guarino ◽  
R. James Lanzi ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Focal Length ◽  
X Rays ◽  
Aluminum Composite ◽  
Photon Detection ◽  
X Ray ◽  
Systematic Uncertainties ◽  
X Ray Imaging ◽  
Photon Detection Efficiency ◽  
Stratospheric Balloon

X-ray polarimetry has seen a growing interest in recent years. Improvements in detector technology and focusing X-ray optics now enable sensitive astrophysical X-ray polarization measurements. These measurements will provide new insights into the processes at work in accreting black holes, the emission of X-rays from neutron stars and magnetars, and the structure of AGN jets. X-Calibur is a balloon-borne hard X-ray scattering polarimeter. An X-ray mirror with a focal length of 8[Formula: see text]m focuses X-rays onto the detector, which consists of a plastic scattering element surrounded by Cadmium-Zinc-Telluride detectors, which absorb and record the scattered X-rays. Since X-rays preferentially scatter perpendicular to their polarization direction, the polarization properties of an X-ray beam can be inferred from the azimuthal distribution of scattered X-rays. A close alignment of the X-ray focal spot with the center of the detector is required in order to reduce systematic uncertainties and to maintain a high photon detection efficiency. This places stringent requirements on the mechanical and thermal stability of the telescope structure. During the flight on a stratospheric balloon, X-Calibur makes use of the Wallops Arc-Second Pointer (WASP) to point the telescope at astrophysical sources. In this paper, we describe the design, construction, and test of the telescope structure, as well as its performance during a 25-h flight from Ft. Sumner, New Mexico. The carbon fiber–aluminum composite structure met the requirements set by X-Calibur and its design can easily be adapted for other types of experiments, such as X-ray imaging or spectroscopic telescopes.

scholarly journals Design and Tests of the Hard X-ray Polarimeter X-Calibur

2014 ◽  
Vol 1 (1) ◽  
pp. 293-297 ◽  
Author(s):  
M. Beilicke ◽  
R. Cowsik ◽  
P. Dowkontt ◽  
Q. Guo ◽  
F. Kislat ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Detection Efficiency ◽  
Grazing Incidence ◽  
High Energy ◽  
X Rays ◽  
Order Unity ◽  
Field Orientation ◽  
X Ray ◽  
New Information ◽  
High Detection Efficiency

X-ray polarimetry promises to give qualitatively new information bout high-energy astrophysical sources, such as binary black hole  systems, micro-quasars, active galactic nuclei, and gamma-ray bursts. We designed, built and tested ahard X-ray polarimeter, X-<em>Calibur</em>, to be used in the focal plane of the InFOCuS grazing incidence hard X-ray telescope.X-<em>Calibur</em> combines a low-Z Compton scatterer with a CZT detector assembly to measure the polarization of 20−60 keV X-rays making use of the fact that polarized photons Compton scatter preferentially perpendicular to the electric field orientation; in principal, a similar space-borne experiment could be operated in the 5−100 keV regime. X-<em>Calibur</em> achieves a high detection efficiency of order unity.

Determination of the detection efficiency of an UTW detector and modelling of spectra used for the quantification of EDS analyses of light elements

1992 ◽  
Vol 50 (2) ◽  
pp. 1234-1235
Author(s):  
Pierre Hovington ◽  
Gilles L'Espéiance
Keyword(s):  
Data Processing ◽  
Detection Efficiency ◽  
Light Element ◽  
X Rays ◽  
Routine Laboratory ◽  
Light Elements ◽  
Characteristic Peak ◽  
Laboratory Procedure ◽  
X Ray

The increased use of Si(Li) energy dispersive x-ray spectrometers (EDS) with a windowless (WL) or ultra thinwindow (UTW) detectors has made the detection of light elements down to Be a routine laboratory procedure. The quantification of EDS spectra implies that the net intensity of the characteristic peak of interest must be determined accurately. For light-element x-rays for which the background is non linear and for which the Kα lines can often overlap with the L and M lines of transition metals, the simple determination of the characteristic intensity is not a straightforward operation and often requires sophisticated data processing. The use of a conventional least-squares fitting technique with prefiltering of standard spectra for deconvolution is made difficult by the non-linearity of the background, the presence of the triggered noise peak below 0.3 KeV, and the lack of appropiate standards. In addition to the difficulty associated with the determination of the net intensity, the uncertainties for the detection efficiency below 1 Kev has limited the use of standardless procedures for quantification.

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