Projection Microscopy and Microanalyses*

1961 ◽  
Vol 5 ◽  
pp. 324-334
Author(s):  
Ong Sing Poen
Keyword(s):  
Pulse Height ◽  
Emission Spectra ◽  
Line Radiation ◽  
Pulse Height Analyzer ◽  
Divergent Beam ◽  
X Ray ◽  
Specimen Holder ◽  
Beam Type ◽  
Fluorescent Radiation ◽  
Ray Projection

AbstractResults of recent experiments on microanalyses with an X-ray projection microscope will be reviewed. As the use of monochromatic radiation is imperative, spectral analyses of the point source were carried out. A simple stationary divergent-beam-type transmission spectrograph was used. The shape and size were miniaturized to fit in the specimen holder of the Norelco projection unit. Emission spectra from clean, targets and the fluorescent radiation emerging from a 10- to 50-μ-diameter spot of contaminated targets and of two-layer targets will be shown. The spectra were recorded photographically. In addition, a proportional counter, in combination with the R.C.L. 128-channel pulse-height analyzer, was used for measuring the ratio of “white” to line radiation.

Pulse-Height Selection in X-Ray Fluorescence

1960 ◽  
Vol 4 ◽  
pp. 370-381
Author(s):  
Kurt F.J. Heinrich
Keyword(s):  
Energy Levels ◽  
Pulse Height ◽  
Fluorescence Analysis ◽  
Higher Order ◽  
Pulse Height Analyzer ◽  
X Ray ◽  
Qualitative And Quantitative ◽  
Systematic Application ◽  
Pulse Height Analysis ◽  
Qualitative Work

AbstractPulse-height analysis is a valuable tool in X-ray fluorescence analysis, both for qualitative and quantitative purposes. The elimination of higher order interferences permits determinations that would otherwise be very difficult or impossible, The systematic application of pulse-height analysis in qualitative work greatly simplifies the interpretation of complex spectra. In certain cases one can apply nondispersive analysis, relying on the pulse-height analyzer alone for separating energy levels of X-ray photons. Technique and limitations of pulse-height analysis will be discussed.

Energy Dispersive Analysis for Adjacent Elements Using Two Single Channel Analyzers

1971 ◽  
Vol 15 ◽  
pp. 197-208
Author(s):  
Hubert K. Chow
Keyword(s):  
Single Channel ◽  
Matrix Effects ◽  
Pulse Height ◽  
Silicon Detector ◽  
Emission Spectra ◽  
Empirical Method ◽  
Energy Dispersive ◽  
Standard Samples ◽  
X Ray ◽  
Adjacent Element

Energy dispersive x-ray analysis has become an extremely useful analytical tool. The technique provides for the direct observation of x-ray emission spectra, eliminating the need for a dispersive crystal. The purpose of this reported investigation was to study the use of the technique with a simple pulse height analyzing system and to develop a routine method for correcting Interferences due to adjacent element spectral overlap and matrix effects.The analyzing system consists of a radioisotope source, a lithium drifted silicon detector, a preamplifier, an amplifier, two single channel analyzers and two digital ratemeters. In order to obtain results suitable for quantative measurement, a two-step empirical method was employed for the correction of peak overlapping and matrix effects. If two peaks in a spectrum overlap at their tails, one can set up a channel width of the analyzer to a region where there are no overlapping pulses. It is then possible to calibrate the ratio of the intensity obtained from this channel to that obtained from the whole peak in its pure state, i.e. without the appearance of a neighbor peak. The actual intensity of the peak in the overlapping spectrum is, therefore, the observed counts multiplied by the ratio. The next step is the correction of matrix effect by means of conventional empirical methods using standard samples. Two types of the samples, Zn-Cu powder mixtures and Ee-Cu in aqueous solutions, were studied to illustrate this method. The usefulness of applying the analyzing system and technique to industrial measurements, either on-line or batch, will also be discussed.

Escape Peaks in X-Ray Diffractometry*

1964 ◽  
Vol 8 ◽  
pp. 118-133 ◽  
Author(s):  
William Parrish
Keyword(s):  
Absorption Edge ◽  
Pulse Height ◽  
Pulse Amplitude ◽  
Silicon Powder ◽  
X Rays ◽  
Pulse Height Analyzer ◽  
Escape Peak ◽  
X Ray ◽  
Absorption Edge Energy ◽  
Detector Element

AbstractEscape peaks occur when the incident X-ray quantum, energy exceeds the absorption edge energy of the detector element and the resulting X-ray fluorescence is lost from the detector. The most common escape peaks result from 1 K-fluorescence in NaI-scintillation counters and Xe K-, Xe L-, and Kr K-fluorescence in proportional counters. The average pulse amplitude of the escape peak is proportional to the difference of the Energies of the incident and fluorescent X-rays. If the intensity of the escape peak is high as in the case of Mo Kα and a kryptoopreportional counter, and the lower level of the pulse height analyzer is raised to reject the escape peak, the quantum counting efficiency may be reduced by a factor of two. When the pulse height analyzer is set for characteristic incident radiation, escape peaks appear in powder patterns at small diffraction angles. These broad low-intensity peaks are often mistakenly identified as resulting from misalignment, scattering, etc. Each powder reflection can produce its own escape peak which occurs at an angle slightly smaller than the absorption edge of the detector element. In a silicon powder pattern the three strongest reflections produce three resolved escape peaks whose peak intensities are about 4% of their corresponding Cu Kα peaks when the X-ray tube is operated at 50 kV. The escape peak intensities decrease with decreasing X-ray tube voltage and disappear when the voltage is lower than the absorption edge energy of the detector element. Absorption edge peaks observed without the upper level of the pulse height analyzer are similar in appearance, intensity, and diffraction angle to the escape peaks. In complex powder patterns the escape peak pattern is unresolved and may produce a number of very broad peaks.

Evaluation of the Energy Dispersive Detector as a Detector-Filter System for the X-Ray Diffractometer

1972 ◽  
Vol 16 ◽  
pp. 322-335 ◽  
Author(s):  
Davis Carpenter ◽  
John Thatcher
Keyword(s):  
Scintillation Detector ◽  
Pulse Height ◽  
Good Deal ◽  
Energy Dispersive ◽  
Maximum Efficiency ◽  
Height Distribution ◽  
Pulse Height Distribution ◽  
Pulse Height Analyzer ◽  
X Ray ◽  
Detector Pulse

AbstractA comparison of the relative merits of the energy dispersive derector-pulse height analyzer, scintillation detector-graphite monochromator, and proportional detector-pulse height analyzer combinations.Typical energy dispersive detectors are not configured for maximum efficiency on the diffractometer. Being only on the order of 3 mm diameter, a good deal of the available information is not collected by the detector. This is especially true with the Wide optics found in modern diffractometers. The energy dispersive detector incorporated into this system is optimized for the x-ray diffractometer. Its detection area is a 1.25 X 0.25 inch rectangle. The resolution is only sufficient to remove the Kβ portion of the spectrum.Conventional diffractometer techniques incorporate either a scintillation detector-crystal monochromator, or a proportional detector-pulse height analyser combination. The question posed is “what are the advantages in signal to noise ratio and pulse height distribution of the energy dispersive-pulse height analyzer over the more conventional arrangements.”

A Technique for Studying Coprecipitated Chromia-Alumina Catalysts by X-Ray Diffraction

1960 ◽  
Vol 4 ◽  
pp. 117-129
Author(s):  
W. L. Kehl
Keyword(s):  
Background Radiation ◽  
Pulse Height ◽  
Chromium Concentration ◽  
White Background ◽  
X Ray Diffraction ◽  
Pulse Height Analyzer ◽  
X Ray ◽  
Gas Proportional Counter ◽  
Diffraction Patterns ◽  
Alumina Catalysts

AbstractA diffractometer equipped with a gas proportional counter and pulse-height analyzer provides a very satisfactory means of recording the X-ray diffraction patterns of chromium-containing materials with Cu Kα radiation. The fluorescent chromium K radiation can be rejected along with much of the white background radiation without appreciable loss of Cu Kα intensity, and the advantages of copper over chromium or molybdenum radiation can be fully utilized. This is illustrated by an X-ray diffraction study of coprecipitated chromia-alumina catalysts, in which the chromium concentration varies between 0 and 37 w, %. At each chromium concentration the precipitate was studied in the washed and dried state, as well as after calcination at 500, 750, and 1400°C. X-ray diffraction patterns are presented to show the phase transformations and sample inhomogenelties that were observed.

scholarly journals Impurity Transport Study of Medium-Z Argon by Means of Soft X-Ray Pulse Height Analyzer in LHD

2007 ◽  
Vol 2 ◽  
pp. S1069-S1069 ◽  
Author(s):  
Sadatsugu MUTO ◽  
Shigeru MORITA ◽  
LHD Experimental Group
Keyword(s):  
Pulse Height ◽  
Pulse Height Analyzer ◽  
X Ray ◽  
Transport Study ◽  
Impurity Transport

High-speed FPGA-based pulse-height analyzer for high resolution X-ray spectroscopy

2005 ◽  
Vol 52 (4) ◽  
pp. 854-860 ◽  
Author(s):  
S. Buzzetti ◽  
M. Capou ◽  
C. Guazzoni ◽  
A. Longoni ◽  
R. Mariani ◽  
...  
Keyword(s):  
High Resolution ◽  
High Speed ◽  
Pulse Height ◽  
Pulse Height Analyzer ◽  
X Ray

Tokamak Fusion Test Reactor prototype x‐ray pulse‐height analyzer diagnostic

1985 ◽  
Vol 56 (5) ◽  
pp. 840-842 ◽  
Author(s):  
K. W. Hill ◽  
M. Bitter ◽  
M. Diesso ◽  
L. Dudek ◽  
S. von Goeler ◽  
...  
Keyword(s):  
Pulse Height ◽  
Pulse Height Analyzer ◽  
X Ray ◽  
Test Reactor

A Combined Focusing X-Ray Diffractometer and Nondispersive X-Ray Spectrometer for Lunar and Planetary Analysis

1965 ◽  
Vol 9 ◽  
pp. 221-241 ◽  
Author(s):  
K. Das Gupta ◽  
Herbert W. Schnopper ◽  
Albert E. Metzger ◽  
Rex A. Shields
Keyword(s):  
Pulse Height ◽  
High Dispersion ◽  
Powdered Sample ◽  
X Rays ◽  
Dual Purpose ◽  
X Ray ◽  
Specimen Holder ◽  
Energy Discrimination ◽  
Line Focus ◽  
Laboratory Analyzer

AbstractAn instrument is described which is intended to perform a dual purpose (elemental-structural) analysis consistent with the environmental conditions implied by lunar or planetary operation. The dififractometer section is based on a modified Seeman-Bohlin focusing principle in which a sharp-line focus target, a powdered sample, and a movable detector slit all lie on the focusing circle. The convolution of the projections on the focal circle, of a narrow receiving slit on the detector, the line focus target, combined with a high dispersion produce higher resolution and intensity than is common with Bragg focusing diflfractorneters with simitar instrumental parameters. The range of d-spacings covered is from 1 to 7 Å (chromium target). The chemical analysis section of the instrument utilizes the fluorescent X-rays produced in the specimen by the primary beam. A proportional counter and pulse-height anaiyzer accomplish detection and energy discrimination. Resolution is low, but the analysis can distinguish between elements in the range of atomic numbers 11 to 29. Data from a breadboard model is presented. The entire unit, although primarily intended to meet the requirements of space, performs equally well as a routine laboratory analyzer. The horizontal, stationary nature of the specimen holder suggests several specific applications.

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