ISSN:0049-8246    

DOI:10.1002/xrs.1300210103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300210104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractCompton scatter corrections are widely used for trace element determinations in geological materials where elements heavier than iron commonly occur only in low concentrations and whose effects on matrix absorption are usually ignored. Problems with the Compton correction for absorption can be seen if the concentrations of these trace elements become anomalously large, perhaps up to a few percent, although the effects can actually become significant at only a few hundred parts per million. When this occurs the simple absorption relationship, estimated at the Compton wavelength, becomes distorted. An iterative algorithm is presented that corrects absorption ratios at any wavelength as absorption edges are encountered during processing and in turn extends the Compton method to the accurate determination of anomalously high trace element concentrations.

ISSN:0049-8246    

DOI:10.1002/xrs.1300210105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractA Monte‐Carlo model was developed for the simulation of x‐ray fluorescence (XRF) from spherical micro‐samples including primary and secondary fluorescence events. The interelement and geometrical effects in XRF microanalysis of individual mineral grains were studied. Calculations were performed for grains of Fe2O3containing minor concentration of Ti and for ZnS grains. The results of calculation indicated that the intensities of excited characteristic x‐rays depend strongly on the diameter of the irradiated particle, the incident microbeam profile and its d

ISSN:0049-8246    

DOI:10.1002/xrs.1300210106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractA method was developed for the determination of major, minor and trace elements in a submarine polymetallic nodule by x‐ray fluorescence spectrometry. Fusion of the sample was performed in gfraphite crucibles using a 1:3 dilution ratio with an Li2B4O7Li2CO3LiNO3flux. Calibration was carried out with synthetic standards. The absorption‐enhancement effects for 28 analytes were each corrected using influence coefficients generated by the COLA equation. The results obtained were in relatively good agreement with the recommended values for the Chinese reference material GSPN‐1. The technique of sample preparation and the use of synthetic standards can also be extended to the analysis of other polymeta

ISSN:0049-8246    

DOI:10.1002/xrs.1300210107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractA method is described for the estimation of relative intensities of weak diagram lines from the microphotometer records of x‐ray emission spectra registered on photographic films. The method is based on first correlating the experimentally determined relative intensities of two intense diagram lines with the theoretically calculated relative intensities. The experimental relative intensities of weak diagram lines are then interpolated to yield the corrected experimental relative intensities. These interpolated experimental relative intensities are found to be in good agreement with the theoretical relative intensities. The method has been applied to some recently reported weak lines in the L‐emission spectra of the rare earth57La to6

ISSN:0049-8246    

DOI:10.1002/xrs.1300210108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractA new correction method for obtaining quantitative electron probe microanalysis results is described. It utilizes data provided by Monte Carlo simulations and tracer measurements to obtain a detailed picture of the way in which the x‐ray emission process is influenced by the relevant experimental parameters. Then empirical equations are derived which model the intensity of x‐ray emission for an extremely wide range of experimental conditions, encompassing electron beam energies from 5 to 40 keV, characteristic x‐ray wavelengths from 11.4 to 0.08 nm, angles of electron incidence from 90° to 40° and elements ranging from beryllium to uranium in the Periodic Table. The method treats separately, as with the traditional approach, the effects of atomic number difference in specimen and standard, x‐ray absorption and x‐ray fluorescence. The correction method was tested on an extensive range of microanalysis data and shown to work well under all conditions, providing chemical compositions which are accutate to within a few percent relative. The capability of handling ultra‐light element (beryllium to sodium) analysis is particularly impressive and the r.m.s. error of 3.8% for carbon analysis on carbides is very close to the errors incurred in measuring actual x‐ray intensities. The correction program is currently being developed for commercial use on IBM‐compatible computers and the final stage in the evolution of the universal correction will be to extend it to deal with the analysis of t

ISSN:0049-8246    

DOI:10.1002/xrs.1300210109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractA knowledge of the spectral distribution method emitted by an x‐ray tube is important for all calculations in quantitative x‐ray fluorescence analysis. A simple way of directly measuring the primary spectrum of an x‐ray tube with a solid‐state detector is presented. For samples which meet thin‐film criteria sensitivity factors based on the measured primary spectrum were calculated and compared with experiment

ISSN:0049-8246    

DOI:10.1002/xrs.1300210110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractUp till now, the well known effective coefficient method was used by referring to a single standard. The SFP (Siemens fundamental parameter) program additionally allows this method to be employed with several standards and to analyse samples containing an element that is not analysed. A modified algorithm, called the trace model, yields an improvement in the precision of the trace element analysis. The different variants are illustrated by practical applications.

ISSN:0049-8246    

DOI:10.1002/xrs.1300210111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300210112

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY