K shell absorption jump ratios and jump factor measurements for some elements in the range of 40 ≤ Z ≤ 50

2019 ◽  
Vol 97 (7) ◽  
pp. 786-790
Author(s):  
A. Turşucu

In this study, K shell absorption jump ratios (JK) and jump factors (rK) of specimens in the atomic number range of 40 ≤ Z ≤ 50 were measured using the energy dispersive X-ray fluorescence (EDXRF) technique. Related specimens were excited using 59.54 keV γ-photons that were radiated from a 241Am point source. Typical K X-rays emitting from specimens were detected from silicon drifted lithium (Si(Li)) semiconductor detector. Derived JK and rK values of related specimens were compared with calculated theoretical and other experimental values. The agreement of measured values was reasonable with theoretical calculations.

1994 ◽  
Vol 51 (2) ◽  
pp. 197-206 ◽  
Author(s):  
S.M. Simabuco ◽  
V.F. Nascimento Filho

Three certified samples of different matrices (Soil-5, SL-1/IAEA and SARM-4/SABS) were quantitatively analysed by energy dispersive X-ray fluorescence with radioisotopic excitation. The observed errors were about 10-20% for the majority of the elements and less than 10% for Fe and Zn in the Soil-5, Mn in SL-1, and Ti, Fe and Zn in SARM-4 samples. Annular radioactive sources of Fe-55 and Cd-109 were utilized for the excitation of elements while a Si(Li) semiconductor detector coupled to a multichannel emulation card inserted in a microcomputer was used for the detection of the characteristic X-rays. The fundamental parameters method was used for the determination of elemental sensitivities and the irradiator or transmission method for the correction of the absorption effect of characteristic X-rays of elements on the range of atomic number 22 to 42 (Ti to Mo) and excitation with Cd-109. For elements in the range of atomic number 13 to 23 (Al to V) the irradiator method cannot be applied since samples are not transparent for the incident and emergent X-rays. In order to perform the absorption correction for this range of atomic number excited with Fe-55 source, another method was developed based on the experimental value of the absorption coefficients, associated with absorption edges of the elements.


1994 ◽  
Vol 51 (2) ◽  
pp. 207-215 ◽  
Author(s):  
S.M. Simabuco ◽  
V.F. Nascimento Filho

The distribution of S, Cl, K and Ca along the profiles of two soils of different texture (Red Yellow Podzolic and Dark Red Latosol) treated with amounts of vinasse equivalent to 4000 m³/ha were studied using energy dispersive X-ray fluorescence, observing a significant increase in the contents of these elements. The same effect was observed for Cu, Zn, Rb and Sr contents in soils treated with vinasse as compared to the control. The concentrations of Al, Si, Ti, Mn, Fe and Zr could also be evaluated but no significant variation was observed due to the high soil initial concentrations of these elements as compared to the low concentrations in the vinasse. Annular radioactive sources of Fe-55 and Cd-109 were employed for the excitation of these elements in the soil samples, treated or not with vinassse. For the detection of the characteristic X-rays, a Si (Li) semiconductor detector was used, coupled to a multichannel emulation card inserted in a microcomputer.


1973 ◽  
Vol 21 (6) ◽  
pp. 580-586 ◽  
Author(s):  
E. W. DEMPSEY ◽  
F. J. AGATE ◽  
M. LEE ◽  
M. L. PURKERSON

X-ray emission spectra have been recorded from several biologic tissues using a multichannel energy-dispersive analyzer with a retractible semiconductor detector coupled to a Cambridge Mark II scanning electron microscope. Particular attention has been given to the detection of silver in experimental argyria, of calcium in dermoid scales and in experimental necrosis of the kidney and of sulfur in the inner and outer portions of reptilian skin. Sulfur and chlorine have been found associated with silver in argyria. Phosphorus was associated with calcium both in the dermal scales and in necrotic areas. In addition to these elements, trace amounts of copper, zinc, lead, sodium, potassium, iron, arsenic, osmium and uranium have been detected in various normal and experimental situations. The applicability of the combined instrument to cytochemical problems is briefly discussed.


2015 ◽  
Vol 21 (5) ◽  
pp. 1327-1340 ◽  
Author(s):  
Dale E. Newbury ◽  
Nicholas W. M. Ritchie

AbstractA scanning electron microscope with a silicon drift detector energy-dispersive X-ray spectrometer (SEM/SDD-EDS) was used to analyze materials containing the low atomic number elements B, C, N, O, and F achieving a high degree of accuracy. Nearly all results fell well within an uncertainty envelope of ±5% relative (where relative uncertainty (%)=[(measured−ideal)/ideal]×100%). Quantification was performed with the standards-based “k-ratio” method with matrix corrections calculated based on the Pouchou and Pichoir expression for the ionization depth distribution function, as implemented in the NIST DTSA-II EDS software platform. The analytical strategy that was followed involved collection of high count (>2.5 million counts from 100 eV to the incident beam energy) spectra measured with a conservative input count rate that restricted the deadtime to ~10% to minimize coincidence effects. Standards employed included pure elements and simple compounds. A 10 keV beam was employed to excite the K- and L-shell X-rays of intermediate and high atomic number elements with excitation energies above 3 keV, e.g., the Fe K-family, while a 5 keV beam was used for analyses of elements with excitation energies below 3 keV, e.g., the Mo L-family.


Author(s):  
Werner P. Rehbach ◽  
Peter Karduck

In the EPMA of soft x rays anomalies in the background are found for several elements. In the literature extremely high backgrounds in the region of the OKα line are reported for C, Al, Si, Mo, and Zr. We found the same effect also for Boron (Fig. 1). For small glancing angles θ, the background measured using a LdSte crystal is significantly higher for B compared with BN and C, although the latter are of higher atomic number. It would be expected, that , characteristic radiation missing, the background IB (bremsstrahlung) is proportional Zn by variation of the atomic number of the target material. According to Kramers n has the value of unity, whereas Rao-Sahib and Wittry proposed values between 1.12 and 1.38 , depending on Z, E and Eo. In all cases IB should increase with increasing atomic number Z. The measured values are in discrepancy with the expected ones.


Author(s):  
Marc H. Peeters ◽  
Max T. Otten

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.


Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.


Author(s):  
Y. Sato ◽  
T. Hashimoto ◽  
M. Ichihashi ◽  
Y. Ueki ◽  
K. Hirose ◽  
...  

Analytical TEMs have two variations in x-ray detector geometry, high and low angle take off. The high take off angle is advantageous for accuracy of quantitative analysis, because the x rays are less absorbed when they go through the sample. The low take off angle geometry enables better sensitivity because of larger detector solid angle.Hitachi HF-2000 cold field emission TEM has two versions; high angle take off and low angle take off. The former allows an energy dispersive x-ray detector above the objective lens. The latter allows the detector beside the objective lens. The x-ray take off angle is 68° for the high take off angle with the specimen held at right angles to the beam, and 22° for the low angle take off. The solid angle is 0.037 sr for the high angle take off, and 0.12 sr for the low angle take off, using a 30 mm2 detector.


2009 ◽  
Vol 19 (03n04) ◽  
pp. 167-173 ◽  
Author(s):  
B. B. TRIPATHY ◽  
T. R. RAUTRAY ◽  
SATYA R. DAS ◽  
MANAS R. DAS ◽  
V. VIJAYAN

The analysis of some of the Indian silver coins during British rule were analysed by Energy Dispersive X-Ray Fluorescence Technique. Eight elements namely Cr , Fe , Ni , Cu , Zn , As , Ag and Pb were estimated in this study which also seems to indicate the fragmentation as well as the impoverishment of the power for the regimes that had produced the studied coins. While Cu and Ag were present as major elements, other elements were found to be present in minor concentration.


2004 ◽  
Vol 14 (03n04) ◽  
pp. 133-139 ◽  
Author(s):  
T. R. RAUTRAY ◽  
V. VIJAYAN ◽  
P. K. NAYAK ◽  
S. JENA

Coins are important archaeological objects that can provide useful information regarding preparation methodology and provenance. Their classification plays a fundamental role in dating historical events, in constructing trade routes and in establishing the welfare of population. Several Indian copper coins of different periods have been studied using Energy Dispersive X-ray Fluorescence (EDXRF) spectroscopic technique. The method is rapid, efficient, multi elemental and non-destructive in nature. Concentrations of the major and trace elements like Ca , Ti , V , Cr , Mn , Fe , Co , Ni , Cu , Zn , As and Pb have been estimated in these copper coins. In the present investigation, an attempt has been made to characterize some Indian copper coins of different periods using EDXRF technique.


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