MEASUREMENT OF LOW ENERGY DETECTION EFFICIENCY OF A PLASTIC SCINTILLATOR: IMPLICATIONS ON THE LOWER ENERGY LIMIT AND SENSITIVITY OF A HARD X-RAY FOCAL PLANE COMPTON POLARIMETER

2014 ◽  
Vol 212 (1) ◽  
pp. 12 ◽  
Author(s):  
T. Chattopadhyay ◽  
S. V. Vadawale ◽  
M. Shanmugam ◽  
S. K. Goyal
Keyword(s):  
Focal Plane ◽  
Lower Energy ◽  
Plastic Scintillator ◽  
Detection Efficiency ◽  
Energy Detection ◽  
Low Energy ◽  
Energy Limit ◽  
X Ray

Evaluating 30mm2 Si(Li) detectors for light-element x-ray analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 208-209
Author(s):  
Shaul Barkan
Keyword(s):  
Detection Efficiency ◽  
Light Element ◽  
Energy Detection ◽  
Low Energy ◽  
Dead Layer ◽  
Electronic Noise ◽  
Special Effect ◽  
X Ray ◽  
Two Factors ◽  
Detector Crystal

Light element x-ray microanalysis with the Si(Li) detecor is dependent on two detector crystal characteristics. The first is resolution, which has been traditionally standardized to be FWHM at Mn Kα. The second factor is efficiency, which is primarily but not entirely established by the detector area. These two factors effect light element sensitivity in an inverse manner. A premium resolution detector can be produced by minimizing the area, but the efficiency, as previously discussed , is directly proportional to the detector area.A special effect of efficiency degradation exists in the very low energy end of the spectrum where the x-ray energy pulses are approximately equal to the electronic noise level. The detector dead layer plays an important role in the low energy detection efficiency, since good, low energy efficiency is much more important than good manganese resolution or good electronic noise resolution.In a common 10mm2 Kevex detector, ~135 eV resolution at Mn is obtainable and the electronic noise resolution is 65 eV.

A Method to Test the Performance of an Energy-Dispersive X-Ray Spectrometer (EDS)

2014 ◽  
Vol 20 (5) ◽  
pp. 1556-1564 ◽  
Author(s):  
Vasile-Dan Hodoroaba ◽  
Mathias Procop
Keyword(s):  
Software Package ◽  
Detection Efficiency ◽  
Energy Detection ◽  
Energy Scale ◽  
Low Energy ◽  
Energy Dispersive ◽  
Test Material ◽  
X Ray ◽  
Operation Conditions ◽  
Pile Up

AbstractA test material for routine performance evaluation of energy-dispersive X-ray spectrometers (EDS) is presented. It consists of a synthetic, thick coating of C, Al, Mn, Cu, and Zr, in an elemental composition that provides interference-free characteristic X-ray lines of similar intensities at 10 kV scanning electron microscope voltage. The EDS energy resolution at the C-K, Mn-Lα, Cu-Lα, Al-K, Zr-Lα, and Mn-Kα lines, the calibration state of the energy scale, and the Mn-Lα/Mn-Kα intensity ratio as a measure for the low-energy detection efficiency are calculated by a dedicated software package from the 10 kV spectrum. Measurements at various input count rates and processor shaping times enable an estimation of the operation conditions for which the X-ray spectrum is not yet corrupted by pile-up events. Representative examples of EDS systems characterized with the test material and the related software are presented and discussed.

PRELIMINARY MEASUREMENTS OF THE LOW ENERGY DETECTION EFFICIENCY OF A Si(Li) DETECTOR FOR PIXE APPLICATIONS

2002 ◽  
Vol 12 (03n04) ◽  
pp. 71-78
Author(s):  
M. RODRIGUEZ ◽  
T. YONEZAWA ◽  
K. ISHII ◽  
S. MATSUYAMA ◽  
H. YAMAZAKI ◽  
...  
Keyword(s):  
Detection Efficiency ◽  
Energy Detection ◽  
Thick Target ◽  
Incident Electron ◽  
Thin Layers ◽  
Low Energy ◽  
Dead Layer ◽  
Bremsstrahlung Spectrum ◽  
Significant Discrepancy ◽  
The One

The low energy detection efficiency of a Si ( Li ) detector is measured in this work. The continuous bremsstrahlung spectrum produced by bombarding a thick C target with an electron beam is used as the standard radiation source. The bremsstrahlung spectrum for a thick C target is calculated from tabulated data assuming the thick target to consist of an array of thin layers applying the respective attenuation correction for photons emitted in each thin layer. The bremsstrahlung spectra for three incident electron energies (10, 12 and 15 keV) are measured and compared with the calculated ones. The relative efficiency is obtained and compared with a calculated efficiency based on the detector specifications. The efficiency measured for those three incident electron energies on the thick target are consistent with each other. The region limited by 2 keV < k < 6 keV , where k is the X-ray energy, exhibits a significant discrepancy between measurements and calculated efficiencies. A possible explanation of the observed discrepancy is that the real thickness of the Si dead layer is thinner than the one reported by the manufacturer. The obtained efficiency values are valid within the range 0.8 keV < k < 12.5 keV .

RESONANT INELASTIC SOFT X-RAY SCATTERING OF INSULATING CUPRATES

2002 ◽  
Vol 09 (02) ◽  
pp. 1103-1108 ◽  
Author(s):  
L.-C. DUDA ◽  
T. SCHMITT ◽  
J. NORDGREN ◽  
G. DHALENNE ◽  
A. REVCOLEVSCHI
Keyword(s):  
High Resolution ◽  
Energy Loss ◽  
Lower Energy ◽  
High Energy ◽  
Low Energy ◽  
The Novel ◽  
Excitation Peak ◽  
X Ray ◽  
X Ray Scattering ◽  
Large Spread

We have performed high-resolution inelastic X-ray emission scattering experiments at the Cu 3p-, Cu 3s-, and O 1s-resonances of the insulating cuprates CuGeO 3, CuO, La 2 CuO 4, and SrCuO 2. We introduce the novel low-energy s-edge Cu-RIXS which reveals a dd-excitation peak, which was previously unobserved due to insufficient resolution and intensity in high-energy (Cu 1s RIXS). Also, O 1s-RIXS of all cuprate sample is investigated. Surprisingly, there is a large spread in the energy loss values of the RIXS features for different compounds and we explain this by assigning the larger energy features to the occurrence of a Zhang–Rice singlet while the lower energy feature (only observed for CuGeO 3) is assigned to a dd-excitation.

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.

Crystallographic and Molecular Mechanics Study of Imidooxy Anticonvulsants

1997 ◽  
Vol 53 (6) ◽  
pp. 945-952
Author(s):  
M. Ciechanowicz-Rutkowska ◽  
H. F. Lieberman ◽  
M. B. Hursthouse ◽  
K. R. Scott
Keyword(s):  
Solid State ◽  
Molecular Mechanics ◽  
Crystal Structures ◽  
Low Energy ◽  
Conformational Space ◽  
Energy Limit ◽  
Substitution Pattern ◽  
X Ray ◽  
New Compounds ◽  
Low Energy Conformations

X-ray crystal structures have been determined of five compounds closely related to N-benzyl-2-azaspiro[4.4]-nonane-l,3-dione (1), which is inactive as an anticonvulsant, and N-(benzyloxy)-2-azaspiro[4.4]nonane-1,3-dione (2), which is active. Conformational analyses have been carried out with (1), (2) and the new compounds N-(2′,4′-dichlorobenzyloxy)-2-azaspiro[4.4]nonane-l,3-dione (3), N-(2′-bromobenzyloxy)-2-azaspiro[4.4]nonane-l,3-dione (4), N-(4′-(trifluoromethyl)benzyloxy)-2-azaspiro[4.4]nonane-l,3-dione (5), which are all active anticonvulsants, and N-(4′-chlorobenzyloxy)-2-azaspiro[4.4]nonane-l,3-dione (6) and N-(4′-bromobenzyloxy)-2-azaspiro[4.4]nonane-1,3-dione (7), which are inactive. Regardless of the substitution pattern, the conformations of compounds (2)–(7) in the crystals are very similar. Among the low-energy conformations, which are well distributed in the conformational space, that present in its solid state is dominant. Ortho-substitution considerably cuts down the number of conformations accessible within the set energy limit. The results of these studies alone do not explain the differences in activity.

Combined XRD and XRF Analysis for Portable and Remote Applications

1994 ◽  
Vol 38 ◽  
pp. 319-324
Author(s):  
Jonathan A. Kerner ◽  
Edward D. Franco ◽  
John Marshall
Keyword(s):  
Powder Diffraction ◽  
Tilt Angle ◽  
Single Photon ◽  
Fluorescence Analysis ◽  
Low Energy ◽  
Energy Limit ◽  
Pure Sample ◽  
X Ray ◽  
Diffraction Peaks ◽  
Prototype Instrument

Abstract A prototype instrument, which provides x-ray powder diffraction and x-ray fluorescence analysis in a compact unit, has been developed to support the needs of NASA for planetary exploration. The instrument uses a 9-watt Fe-anodc x-ray tube and CCD in a fixed geometry for recording powder patterns with a 2θ range of 35°. The fluorescence spectrum for elements below Fe is collected simultaneously with the diffraction data. A shuttered Cd-109 isotopic source with emissions at 22 and 80 keV is used to excite higher energy fluorescence. The low-energy limit for discriminating single photon events was found to be ∼1.5 keV. Al-K could be distinguished from a pure sample, but the spectrum below 6 keV was degraded by the read noise of the CCD, which introduced spectral artifacts. Diffraction peaks from halite had a FWHM of ∼1°(2θ), with major contributions to the width from the use of slit collimation on the source and the low tilt angle of the sample.

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