ISSN:0049-8246    

DOI:10.1002/xrs.1300120102

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

年代:1983

数据来源: WILEY

摘要:

AbstractTwo common methods of applying dead‐time corrections in EDS systems, both of which are carried out internally in the electronics, are examined. The Barnhart method shows serious discrepancies when making dead‐time corrections and in certain cases no correction is made at all. The problem is associated with the reliance on the fast amplifier to count all x‐rays collected by the detector. In practice, however, the fast amplifier does not always succeed in carrying out this function since x‐rays with energies<1500 eV may fall below its threshold level. The problems become worse when a formvar window is substituted for beryllium since a greater proportion of low energy x‐rays can now reach the detector. The magnitude of the discrepancy is shown also to be a function of specimen and electron accelerating voltage. Similar experiments with an EDS system using the Covell method show that no such discrepanc

ISSN:0049-8246    

DOI:10.1002/xrs.1300120103

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

年代:1983

数据来源: WILEY

摘要:

AbstractA new procedure of powder sample preparation for x‐ray emission analysis by melting has been worked out in detail. The mixture sample‐flux was melted and cooled in graphite crucible. The resulting glass disk was ready for direct measurement. The re‐fused graphite electrode of an electric arc furnace was used as the material for the graphite crucible. The dimension and shape of the crucible bottom were determined on the basis of sample holder dimension and sample behaviour during the cooling step. The reproducibility of Kα line measurement was below 1%. Resistance of the crucible to handling and the influence of graphite on Fe Kα, Ca Kα, SKα, Si Kα and Mg Kα line intensities also were i

ISSN:0049-8246    

DOI:10.1002/xrs.1300120104

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

年代:1983

数据来源: WILEY

摘要:

AbstractIt is shown that when a narrow x‐ray beam is used in energy dispersive fluorescence analysis of thick, low‐Z samples large deviations from the predictions of the commonly used fundamental parameter model occur. A simple method by which the effects can be studied empirically is described. An approximate model allowing a direct calculation of the effécts is introduced. The validity of the model has been confirmed experiment

ISSN:0049-8246    

DOI:10.1002/xrs.1300120105

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

年代:1983

数据来源: WILEY

摘要:

AbstractA non‐destructive method for the analysis of materials using gamma ray‐induced fluorescent x‐ray emission has been developed. In this method, special preparation of very thin samples in which the absorption of the incident gamma rays and the emitted fluorescent x‐rays is negligible, is not needed, and the absorption correction is determined experimentally. A suitable choice of the incident gamma ray energies is made to minimise enhancement effects through selective photoionization of the elements in the sample. The method is applied to the analysis of a typical sample of the soldering material using 279 keV and 59.5 keV gamma rays from203Hg and241Am radioactive sources respectively. The results of the analysis are found to agree well with those obtained from the chemical a

ISSN:0049-8246    

DOI:10.1002/xrs.1300120106

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

年代:1983

数据来源: WILEY

摘要:

AbstractIn the Japanese Industrial Standard for the x‐ray fluorescence analysis of steels, the ‘estimated binary calibration curve’ method has been adopted. In this method, the calibration curve for the binary system, consisting of an analyte and the principal constituent elements is estimated and derived by using multicomponent standard samples. The measured x‐ray intensity is first converted into a tentative analytical value from this calibration curve, and then the analytical result is derived from this tentative value using the correction procedure. In this paper, some methods and standard samples of making the estimated binary calibration curve are compared and discussed, also, the characteristics of the JIS method are de

ISSN:0049-8246    

DOI:10.1002/xrs.1300120107

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe rigorous relationship existing between effective fundamental coefficients, as expressed by Tertian's identities, and Sherman's basic equations for x‐ray fluorescence intensities is recalled. The properties of these coefficients in the case of binary systems are described, for usual as well as for some anomalous situations, and a general, accurate hyperbolic equation is suggested to account for coefficient variation with composition. The properties of effective coefficients in the general case of multicomponent systems (alloys, etc.) are then examined, and illustrated on the typical FeNiCr ternary system, confirming the essential exactness of this approach. As a consequence, the authors propose to make use of calculated effective coefficients to apply mathematical matrix corrections, and give a first outline of the analytical proc

ISSN:0049-8246    

DOI:10.1002/xrs.1300120108

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe stoichiometry and thickness of TiNxOyfilms has been determined by electron microprobe and nuclear microanalysis. The difficulty arising in the electron microprobe from the interference between NKα and TiLI lines has been overcome by using a suitable Monte Carlo computing scheme. This procedure takes into account the SiKα intensity which was found to be sensitive to composition and thickness of the overlying TiNxOyfilm. The good agreement between electron microprobe and nuclear microanalysis results indicate the validity of the metho

ISSN:0049-8246    

DOI:10.1002/xrs.1300120109

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe usual method of polishing the surface of a solid sample for examination using the x‐ray microprobe technique cannot be adopted for clay minerals. A modified method is suggested and its validity is tested using vermiculite mineral. It is observed that precision of quantitative elemental analysis increases significantly according to the present pretreatment procedure; variation from values obtained by wet chemical method is<1% for SiO2, MgO and Fe2O3and 2–3% for the rest. However, values obtained with the x‐ray microprobe technique vary enormously from point to point and this non‐uniformity is explained in terms of the structural characteristics of the clay mineral. The variation increases with the rise in temperature of treatment due to structural modifications occurring during heat treatment. The x‐ray microprobe technique has been found to be quite effective in determination of trace elements such as

ISSN:0049-8246    

DOI:10.1002/xrs.1300120110

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

年代:1983

数据来源: WILEY

摘要:

AbstractA new crystal‐type x‐ray spectrometer is described, which employs a position‐sensitive detector for simultaneous radiation detection in a certain energy range given by the spectrometer design. The main specifications are (a) better energy resolution and (b) longer data collection times compared with an energy‐dispersive spect

ISSN:0049-8246    

DOI:10.1002/xrs.1300120111

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

年代:1983

数据来源: WILEY