ISSN:0049-8246    

DOI:10.1002/xrs.1300180302

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

年代:1989

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300180303

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe response of white radiation, expressed as the number of photons per second and energy interval versus energy, is an essential quantity in quantitative x‐ray fluorescence analysis using fundamental parameters. Our investigations gave the best fit of experimental results obtained from ten elements (6 ≤ Z ≤ 82) in the energy range of photons from 3 to 30 keV by the eq

ISSN:0049-8246    

DOI:10.1002/xrs.1300180304

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

年代:1989

数据来源: WILEY

摘要:

AbstractIn general, the application of the fundamental parameter method in quantitative x‐ray fluorescence analysis is restricted to specimens with plane and smooth surfaces. For such surfaces, the correlation of path lengthsxof incident tube photons andyof escaping fluorescent photons is well defined. For rough surfaces this correlation is described by distribution functions. Thus, forx1≤x≤x2a probability density Ø(y)x1, x2allows the probability ofyvalues to be described within the rangeyA≤y≤yB. From the results it is now possible to describe probability distributions of rough surfaces by means of Monte Carlo ca

ISSN:0049-8246    

DOI:10.1002/xrs.1300180305

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

年代:1989

数据来源: WILEY

摘要:

AbstractMetallic shred obtained by turning bulk copper, brass and steel was embedded in resin and count rates were measured from these specimens and from the original bulk material. The specimens were then sliced into 0.5 mm thick sheets parallel to the plane of the x‐ray beams and the distribution of the metal within each cut was mapped by an optical scanner. Fundamental parameter calculations were applied to compute the count rates from the shred specimens pixel by pixel according to the map and also the count rate ratios relative to the bulk material of the same composition. Whereas count rates between different measurement positions may vary by more than an order of magnitude owing to the statistical distribution of the metal grains, the computed values agree to within (typically) 10% (relative) with the experimental data from matching specimen area

ISSN:0049-8246    

DOI:10.1002/xrs.1300180306

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

年代:1989

数据来源: WILEY

摘要:

AbstractBy using the total reflecting properties of x‐rays inside glass capillary tubes, intense fine or microbeams of x‐rays can be obtained. In combination with conventional diffraction x‐ray tubes, microbeams with a diameter of a few micrometres and with an intensity sufficient for trace element analysis can be achieved. The basic physics behind the capillary technique is reviewed and an energy‐dispersive x‐ray fluorescence microbeam spectrometer for trace element analysis is described. Examples of applications of the microbeam spectrometer are given and the future perspectives of the capillary technique are

ISSN:0049-8246    

DOI:10.1002/xrs.1300180307

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

年代:1989

数据来源: WILEY

摘要:

AbstractComputers have been used in quantitative x‐ray spectroscopy since the 1950s. The algorithms first used were usually based on non‐physical models and were dependent on a large number of calibration data from standard samples. In parallel with the development of the energy‐dispersive x‐ray fluorescence (EDXRF) technique, new software algorithms have been developed based on realistic physical models (e.g. fundamental parameter programs). A review of the basic properties of these programs is given and different methods for peak fitting are discussed. In order to handle and to obtain a survey of the large number of data generated by multi‐element methods such as EDXRF, various ‘post‐processing’ techniques have been developed, and examples of these kinds of techn

ISSN:0049-8246    

DOI:10.1002/xrs.1300180308

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

年代:1989

数据来源: WILEY

摘要:

AbstractThe x‐ray fluorescence intensity of a sample contains the product of two angular‐dependent factors: the first describes the angular dependence of the absorption of both incident and emitted radiation and the second is a geometrical factor accounting for the angular variation of irradiated and detected surface area. Theory for the angular dependence of x‐ray intensities is presented. Good agreement is found with experimental data, measured with a novel focusing spectrometer using a small silicon detector. Measurement of the angular dependence of intensities is especially promising for the analysis of multi‐layer

ISSN:0049-8246    

DOI:10.1002/xrs.1300180309

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

年代:1989

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300180310

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

年代:1989

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300180311

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

年代:1989

数据来源: WILEY