ISSN:0049-8246    

DOI:10.1002/xrs.1300160502

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

年代:1987

数据来源: WILEY

摘要:

AbstractSpectra have been recorded from monochromatized Kα1, Kβ1and Lα1X‐rays in the 3—16 keV energy region incident on an Si(Li) detector. An analytic lineshape consisting of a Gaussian plus two Gaussian‐exponential convolutes fits these well, except at very low energy. The intensities and parameters of these tails are explored in the context of the processes responsible, and the behaviour of the shorter tail is compared with the predictions of a model calculation of Auger and photoelectron escape. The well behaved energy dependence of the tailing parameters improves the prospects for more accurate fitting of complex XRF, EPMA and PIXE

ISSN:0049-8246    

DOI:10.1002/xrs.1300160503

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

年代:1987

数据来源: WILEY

摘要:

AbstractKα and Kβ X‐ray fluorescence cross‐sections were measured for V, Mn, Co, Br, Rb, Mo, In, Sb, I and Cs at nine excitation energies ranging from 8 to 60 keV using energy‐dispersive X‐ray fluorescence spectrometry. The results were in good agreement with the theoretical values calculated using photoionization cross‐sections based on the Hartree‐Fock

ISSN:0049-8246    

DOI:10.1002/xrs.1300160504

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

年代:1987

数据来源: WILEY

摘要:

AbstractRepresentative production cross‐sections for bremsstrahlung, which constitutes an unavoidable spectral background in an X‐ray analysis using electron beam excitation, have been calculated as a function of target and angle for incident electrons in the energy range 0.2—10 MeV. These values, used in conjunction with the corresponding K X‐ray production cross‐sections and non‐fundamental experimental variables particular to each laboratory (detector resolution and ambient background), determine the feasibility of a K X‐ray analysis by direct electron beam excitation, and permit the evaluation of an ideal de

ISSN:0049-8246    

DOI:10.1002/xrs.1300160505

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe effect of the sample grinding time on X‐ray spectrometric results was examined on real samples (limonite iron ore, sinter mixture and blast furnace slag). Comparative results were obtained for X‐ray diffraction analysis and scanning electron microscopic analysis. The optimal grinding time depended on the type of analyte and on the phase composition of the sam

ISSN:0049-8246    

DOI:10.1002/xrs.1300160506

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe source‐sample‐detector efficiency for the recessed source geometry was evaluated, using Monte Carlo techniques, for a variety of samples and sources and found to be superior to that for other geometries in energy‐dispersive X‐ray fluorescence analysis. The samples considered were those with atomic number in the range 14—44 and the radioactive sources were55Fe,244Cm and109Cd. Efficiencies well above 1% can be achieved for the recessed source geometry and samples with atomic number above 20. The values attainable are around four times larger than those for the annular source

ISSN:0049-8246    

DOI:10.1002/xrs.1300160507

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe determination of As making use of the Kα net intensity requires subtraction of the overlapping Pb Lα peak. As the interfering intensity cannot be measured directly, a calculated value has to be obtained from measurement at the Pb Lβ line. A mathematical approach was developed which is based on a typical mean value for the ratio between the Pb Lα and Lβ net intensities. Three measurements per sample are required and the routine calibration procedure is set up with three standard samples. Measurements are fed into a computer programmed to calculate both As and Pb concentrations. The programme corrects for matrix effects by means of one of the measurements that is taken at a chosen background point.The method was devised for fast routine analysis and can be applied to samples of varied composition with the limitation that the As and Pb emission lines are not subjected to significant enhancement. Samples are prepared by grinding the material to a suitable fineness and then pressing it into a tablet. The attainable accuracy and limit of detection for As depend on the Pb level present in each sa

ISSN:0049-8246    

DOI:10.1002/xrs.1300160508

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

年代:1987

数据来源: WILEY

摘要:

AbstractAbsolute values of concentrations of zinc and arsenic for ceramics were obtained using an energy‐dispersive X‐ray fluorescence technique. One hundred and fifteen pieces of Chinese Jingdezhen porcelains from late Ming to 1983, including a few non‐Jingdezhen pieces, were studied. For all pieces of Chinese porcelains made in Jingdezhen from late Ming to the Republic period, the results show that zinc was present in very small quantities (<70 ppm) whereas arsenic was completely absent. However, after World War II, many pieces were found to contain relatively large concentrations of both zinc and/or arsenic. This could then be a simple, non‐destructive method of detecting moder

ISSN:0049-8246    

DOI:10.1002/xrs.1300160509

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

年代:1987

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300160512

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

年代:1987

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300160501

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

年代:1987

数据来源: WILEY