Factors influencing x-ray scintillation-counter metrological-characteristic stability

AbstractA portable, battery-operated X-ray fluorescence analyzer weighing 15 lb is described, consisting of a Nal(Tl) scintillation-counter probe and an electronic unit with a single-channel pulse-height analyzer and reversible scaler. Radioisotope X-ray sources are used for excitation of the sample and, where necessary, balanced filters for resolution of neighboring characteristic X-rays. Emphasis has been placed on designing and producing an instrument that is easy and convenient to operate in laboratory, factory, or field conditions and that can equally well be used to measure extended surfaces, such as rock faces, or finite samples in the form of powders, briquettes, or liquids. The feasibility of the following analyses has been studied by using for each determination the appropriate radioisotope source and filters: sulfur in coal; calcium and iron in cement raw mix; copper in copper ores; and vanadium, chromium, molybdenum, and tungsten in steels. Detection limits, based on counting statistics obtained in count times of 10 to 100 sec, range from 0.03% for copper in ores to 0.2% for sulfur in coal. Both matrix absorption and enhancement effects were encountered and were eliminated or reduced substantially by suitable choice of source energy, by the use of nomograms, or by semiempirical correction factors based on attenuation or scattering coefficients.

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X-ray photoelectron spectroscopy analysis as a tool to assess factors influencing magnetic anisotropy type in Co/MgO system with gold interlayer

Scripta Materialia ◽

10.1016/j.scriptamat.2017.10.006 ◽

2018 ◽

Vol 145 ◽

pp. 50-53 ◽

Cited By ~ 5

Author(s):

Iraida N. Demchenko ◽

Yevgen Syryanyy ◽

Yevgen Melikhov ◽

Laurent Nittler ◽

Leszek Gladczuk ◽

...

Keyword(s):

Magnetic Anisotropy ◽

Photoelectron Spectroscopy ◽

Spectroscopy Analysis ◽

X Ray ◽

Factors Influencing

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The Fabrication of Mercuric Iodide Detectors for Use in Wavelength Dispersive X-Ray Analysers and Backscatter Photon Measurements

MRS Proceedings ◽

10.1557/proc-16-207 ◽

1982 ◽

Vol 16 ◽

Cited By ~ 10

Author(s):

John H. Howes ◽

John Watling

Keyword(s):

Room Temperature ◽

Gamma Ray ◽

Surface Passivation ◽

Electrical Contact ◽

Scintillation Counter ◽

Radiation Detectors ◽

Nuclear Radiation ◽

Gamma Ray Spectrometry ◽

Mercuric Iodide ◽

X Ray

ABSTRACTThis paper describes the fabrication of mercuric iodide nuclear radiation detectors suitable for X and gamma ray spectrometry at room temperature. The active area of the detectors studied are between 0.2 and 1.5cm sq and they are up to 0.5mm thick. The method of producing a stable electrical contact to the crystal using sputtered germanium has been studied. The X-ray resolution of a 1.5cm sq. area detector at 32 keV is 2.3 keV FWHM when operated at room temperature in conjunction with a time variant filter amplifier. A factor which is important in the fabrication of the detector is the surface passivation necessary to achieve a useful detector life.This type of detector has been used on a wavelength dispersive X-ray spectrometer for energy measurements between 10 and 100 keV. The advantages over the scintillation counter, more commonly used, is the improved resolution of the HgI2 detector and its smaller size. The analyser is primarily used for the detection of low levels of heavy metals on particulate filters. The detectors have also been used on an experimental basis for gamma ray backscatter measurements in the medical field.

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An X-Ray Small-Angle Scattering Instrument

Advances in X-ray Analysis ◽

10.1154/s0376030800004961 ◽

1967 ◽

Vol 11 ◽

pp. 332-338 ◽

Cited By ~ 2

Author(s):

Donald M. Koffman

Keyword(s):

Small Angle ◽

Scintillation Counter ◽

Small Angle Scattering ◽

High Angular Resolution ◽

X Ray Diffraction ◽

Multiple Diffraction ◽

Double Crystal ◽

X Ray ◽

Angle Scattering ◽

Diffraction Patterns

AbstractAn X-ray small-angle scattering instrument is described which is used for recording X-ray diffraction patterns or small-angle X-ray scattering curves in an angular region very close to the direct beam. The measurement of X-ray intensity is accomplished with standard geiger or scintillation counter techniques. The instrument is designed for use with a spot-focus or vertical-line X-ray source, In essence, it is a multiple-reflection double-crystal diffractometer, based on a concept developed by Bonse and Hart, employing two grooved perfect germanium crystals arranged in the parallel position. Multiple diffraction from these crystals produces a monochromated X-ray beam which can be several millimeters wide while still exhibiting extremely high angular resolution. As a result, effective sample volumes can be employed with maximum volume-to-thickness ratios. The principal features of the instrument are discussed with emphasis on the advantages of this device over those employing complex slit systems and film-re cording techniques, Data are presented to illustrate the operation, intensity, and resolution of the unit.

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The Gas Proportional Scintillation Counter as a Room-Temperature Detector For Energy-Dispersive X-Ray Fluorescence Analysis

Advances in X-ray Analysis ◽

10.1154/s0376030800009496 ◽

1981 ◽

Vol 25 ◽

pp. 39-44 ◽

Cited By ~ 1

Author(s):

C. A. N. Conde ◽

L. F. Requicha Ferreira ◽

A. J. de Campos

Keyword(s):

Room Temperature ◽

Scintillation Counter ◽

Fluorescence Analysis ◽

Energy Dispersive ◽

X Rays ◽

Mercuric Iodide ◽

X Ray ◽

Temperature Detector ◽

Portable Instruments ◽

Physical Principles

AbstractA review of the basic physical principles of the gas proportional scintillation counter is presented. Its performance is discussed and compared with that of other room-temperature detectors in regard to applications to portable instruments for energy-dispersive X-ray fluorescence analysis. It is concluded that the gas proportional scintillation counter is definitely superior to all other room-temperature detectors, except the mercuric iodide (HgI2) detector. For large areas or soft X-rays it is also superior to the HgI2 detector.

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