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.

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 .

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.

An Introduction to Low Energy X-Ray and Electron Analysis

1969 ◽  
Vol 13 ◽  
pp. 1-25 ◽  
Author(s):  
Burton L. Henke
Keyword(s):  
Electron Spectroscopy ◽  
Auger Electron ◽  
Light Element ◽  
Low Energy ◽  
X Rays ◽  
Excitation Spectra ◽  
X Ray ◽  
Langmuir Blodgett ◽  
Electrostatic Analyzer ◽  
Introductory Review

This is an introductory review of the physics and applications of low energy x-rays and electrons in the 10-1000 ev region. The basic interactions of these radiations within matter are discussed and typical de-excitation spectra, fluorescent x-ray and photoAuger electron, are presented. Specific examples of spectrographic methods and instruments for the low energy region are described as “based upon the use of long-spaced, Langmuir-Blodgett type of multilayers for ultrasoft x-ray analysis and the use of the hemispherical electrostatic analyzer for photo-Auger electron spectroscopy. Some examples of spectrographic signal, signal/background, and resolution are presented for applications to light element fluorescence, valence emission band, and photo-Auger electron analysis. The special aspects of the low energy x-ray analysis of high temperature plasmas and of x-ray astronomical sources in general are described.

Low Energy X-Ray Transmission Images by using a Microfocus X-Ray Tube and a be-Window X-Ray Image Intensifier(XRII)

1998 ◽  
Vol 4 (S2) ◽  
pp. 494-495
Author(s):  
H. Konuma ◽  
K. Kuroki ◽  
K. Kurosawa ◽  
N. Saitoh
Keyword(s):  
Real Time ◽  
Light Element ◽  
Image Intensifier ◽  
High Energy ◽  
Low Energy ◽  
Absorption Coefficients ◽  
Tube Voltage ◽  
Time Resolved ◽  
X Ray ◽  
Time Resolved Measurements

Photographs of x-ray transmission images by x-ray films have been used for observing the inside nondestructively. Further, Imaging Plates(IP) are used for precise measurements of x-ray diffraction patterns. But, these integrating area detectors are not suitable for real time nor time resolved measurements. For real time and time resolved measurements, the X-Ray Image Intensifier(XRII, a large image tube that converts an x-ray image into a visible image) is used for biological x-ray TV systems, x-ray nondestructive inspection systems etc. These TV x-ray image systems require high energy x-rays, x-ray tube voltage of 30 to 150 kV, and show faint contrast for x-ray images of light element substances owing to its low absorption coefficients. However, light elements have intense x-ray absorption coefficients in a low energy x-ray region, x-ray tube voltage of 5 to 20 kV, and give fine contrast for x-ray images of light element substances.

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.

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.

INFLUENCE OF WINDOW EFFECT OF SEMICONDUCTOR X-RAY DETECTORS ON THE RESPONSE FUNCTION AND DETECTION EFFICIENCY

1992 ◽  
Vol 02 (03) ◽  
pp. 255-262
Author(s):  
K. SHIMA
Keyword(s):  
Response Function ◽  
Detection Efficiency ◽  
Collection Efficiency ◽  
Dead Layer ◽  
Charge Collection ◽  
Charge Collection Efficiency ◽  
X Ray ◽  
Window Effect ◽  
Low Energy Tail ◽  
The Dead

In order to search the dead layer of a Si(Li) x-ray detector, the jump ratio of the detection efficiency observed at the Si-K-edge energy was precisely measured by changing the incident photon energies at around 1.84 keV by using monoenergetic photons provided by SOR. Here, the dead layer is meant to be the Si region where the charge collection efficiency, η, is zero. As the result, the dead layers for two detectors investigated at present turned out to be absent. On the other hand, the Si front layers in which the charge collection is incomplete (0<η<1) were estimated to be 0.26 µm and 0.17 µm from a simple analysis for low energy tail spectrum. From these results, the effect of detector window on the response function and detection efficiency is discussed.

Low Energy X-Ray and Electron Absorption Within Solids (100-1500 ev Region)

1973 ◽  
Vol 17 ◽  
pp. 150-213 ◽  
Author(s):  
Burton L. Henke ◽  
Eric S. Ebisu
Keyword(s):  
Cross Sections ◽  
Energy Region ◽  
Auger Electron ◽  
Light Element ◽  
Low Energy ◽  
Interaction Cross Section ◽  
Interaction Coefficients ◽  
Element Analysis ◽  
X Ray ◽  
Precise Knowledge

AbstractQuantitative analysis by x-ray fluorescence and photoelectron and Auger electron analysis can be effectively extended through a precise knowledge of the total aad subshell photoionization cross sections. Light element and intermediate element analysis, as based upon K and L series fluorescence respectively, involve x-ray interactions in the low energy region, Optimized analysis for essentially all the elements by x-ray induced photoelectron and Auger electron spectroscopy involves both x-ray and electron interactions in the low energy region. Unfortunately, theory and measurement for interaction cross sections in this 100-1500 eV region are difficult, particularly for the heavier elements. Nevertheless, recent advances in experimental and computerized-theoretical techniques for the determination of low energy interaction coefficients do permit establishing appreciatly more complete tabulations of cross sections than are currently available in this energy region.In this paper, the types of interaction cross section data that are needed for quantitative x-ray and electron analysis are defined. Such data that are available from experiment and from theory are reviewed and compared. Some newer techniques for the measurement of cross sections are discussed. And finally, new “state of the art” tables are presented for the mass absorption coefficients of all of the elements and of some special laboratory materials. These are tabulated specifically for twenty-six of the most commonly applied characteristic wavelengths in the 8-110 A region and are based upon the best currently available theoretical and experimental data.

scholarly journals Enhancement of Low Energy / Light Element Energy Dispersive Analysis in the Scanning Electron Microscope Using a Non-Focusing X-Ray Optic

2009 ◽  
Vol 15 (S2) ◽  
pp. 218-219
Author(s):  
RE Edelmann ◽  
V Vasudevan ◽  
D Kohls ◽  
J Ullmer
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Light Element ◽  
Low Energy ◽  
Energy Dispersive ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Dispersive Analysis ◽  
Scanning Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

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