Practical X-Ray Spectrometry

1969
ISBN: 978-1-4684-6284-5
Verlag: Springer

Buch, Englisch, 190 Seiten, Format (B × H): 140 mm x 216 mm, Gewicht: 269 g

X-ray fluorescenct" spectrometry is now widely accepted as a highly versatile and potentially accurate method of instrumental elemental analysis and so it is somewhat surprising that although the volume of published work dealing with the technique is high the number of textbooks dealing exclusively with its application is relatively few. Without wishing to detract from the excellence of the textbooks which are already available we have both felt for some time, that a great need exists for a book dealing with the more practical aspects of the subject. For a number of years we have been associated with the provision and arrangement of X-ray schools for the training of new X-ray spectroscopists as well as in the organisation of conferences and sym­ posia whose aims have been to keep the more experienced workers abreast with the latest developments in instrumentation and techniques. In all of these ventures we have found a considerable dearth of reference work dealing with the reasons why an X-ray method has not succeeded as opposed to the multitude of success stories which regularly saturate the scientific press. In this book, which is based on lecture notes from well established courses in X-ray fluorescence spectrometry, we have tried to cover all of the more usual practical difficulties experienced in the application of the method and we have endeavoured to keep the amount of purely theoretical data at a minimum.

Zielgruppe

Research

Autoren/Hrsg.

Jenkins

Inhaltsverzeichnis

1: Physics of X-Rays.- 1.1 Origin of X-rays.- 1.2 Production of X-rays.- 1.3 Properties of X-rays.- 1.4 Excitation of fluorescence radiation in the sample.- 2: Dispersion.- 2.1 General.- 2.2 Geometric arrangement of the spectrometer.- 2.3 Effective range of the spectrometer.- 2.4 Dispersion efficiency.- 2.5 Broadening of line profile.- 2.6 Collimation requirements of the spectrometer.- 2.7 Reflection efficiency.- 2.8 Filters to increase resolving power.- 2.9 Problems experienced in the application of crystal dispersion.- 2.10 Dispersion of soft X-rays.- 2.11 Comparison of the methods for long wavelength dispersion.- 3: Detection.- 3.1 General.- 3.2 Gas filled detectors.- 3.3 The scintillation counter.- 3.4 Comparison of detectors.- 4: Pulse Height Selection.- 4.1 Principle of pulse height selection.- 4.2 Automatic pulse height selection.- 4.3 Applications of pulse height selection.- 4.4 Theoretical application of pulse height selection.- 4.5 Practical problems arising in pulse height selection.- 4.6 Pulse amplitude shifts.- 4.7 Pulse amplitude distortions.- 5: Counting Statistics.- 5.1 introduction.- 5.2 Definition of statistical terms.- 5.3 Random distribution of X-rays.- 5.4 Choice of fixed time or fixed count.- 5.5 Limit of counting error.- 5.6 Counting error in the net intensity.- 5.7 Selection of optimum counting times.- 5.8 Selection of best conditions for analysis.- 5.9 Selection of best conditions for low concentrations.- 5.10 Errors in using the ratio method.- 5.11 Selection of ratio or absolute counting method.- 5.12 Counting error versus stability.- 5.13 Counting error as a function of total numbers of counts.- 6: Matrix Effects.- 6.1 Errors in X-ray analysis.- 6.2 Elemental interactions.- 6.3 Physical effects.- 7: Quantitative Analysis.- 7.1 General.- 7.2Use of standards.- 7.3 Dilution techniques.- 7.4 Thin film techniques.- 7.5 Mathematical corrections.- 8: Sample Preparation.- 8.1 General.- 8.2 Samples requiring only a simple treatment.- 8.3 Samples requiring significant pre-trcatment.- 8.4 Samples requiring special handling treatment.- 9: Trace Analysis.- 9.1 General.- 9.2 Analysis of low concentrations.- 9.3 Theoretical considerations.- 9.4 Statistical definition.- 9.5 Figure of merit (or quality function).- 9.6 Generator stability.- 9.7 Effect of long term drift.- 9.8 Variation of detection limit with atomic number.- 9.9 Choice of excitation conditions.- 9.10 Effect of background.- 9.11 Removal of background by polarization.- 9.12 Use of filters.- 9.13 Effect of the matrix.- 9.14 Analysis of limited quantities of material.- 9.15 Theoretical considerations I.- 9.16 Ultimate requirements in sample size.- 9.17 Handling of small samples.- Appendix 1(a).- Appendix 2(a).- Appendix 2(b).- Appendix 3(a).- Appendix 3(b).- Appendix 4.