The mass attenuation coefficient values of the elements are available in the literature [46]. Therefore, the mass attenuation coefficient of a compound can be calculated. Thus and (in Eq. 15) can be calculated provided the molecular formulas of components 1 and 2 are known. It is then possible to calculate the intensity ratio, /u/(/ii)o> as a function of xx. This ratio can also be experimentally obtained. The intensity of peak i of a sample consisting of only 1 is determined [(/ii )o] This is followed by the determination of the intensity of the same peak in mixtures containing different weight fractions of 1 and 2. This enables the experimental intensity ratio, /n/(/n)o, to be obtained as a function of xx. The principles discussed above formed the basis for the successful analyses of quartz-beryllium oxide and quartz-potassium chloride binary mixtures [45]. [Pg.202]

The table of mass attenuation coefficients indicates that for aluminium and the Ka of copper, fim — 264cm2/g. Knowing the density of this metal leads us to the linear coefficient [Pg.419]

Figure 17.10 Mass attenuation coefficient for energetic photons in lead. (From Evans, 1955.) |

It is possible to calculate the mass attenuation coefficients of the analyte and the matrix based on their chemical compositions. This enables the calculation of the relative intensity [Ii / In)o as a function of the weight fraction of the analyte in the mixture and thus generate a theoretical curve. This eliminates the need for the preparation of experimental standard curves. An added advantage of this approach is that there is no requirement of an internal standard. [Pg.4109]

Table 1 Weight Fraction of Minor Phases and Mass Attenuation Coefficient of Aluminium Titanate/Zirconia-Alumina Composites as a Function of Sample |

Position of the emitting atom Resonance-absorption cross section Mass attenuation coefficients Line width Isotope abundance [Pg.359]

Figure 7 The atomic number dependence of attenuation in different energy domains. This is illustrated by how the mass attenuation coefficient of the predominating mode (photoelectric (PE) at 50 keV, incoherent (Inc) at 500 keVand pair production (PP) at 5 MeV) varies with Z. |

Note that the order in which the series of materials occurs is immaterial the contribution of each is weighted according to its areal density and mass attenuation coefficient. [Pg.94]

This approach was used to determine the weight fractions of anhydrous carbamazepine and carbamaze-pine dihydrate when they occurred as mixtures. Based on the mass attenuation coefficients of the anhy-drate and the dihydrate, the intensity ratios [/ii/(fii)o] were calculated as a function of the anhydrate content in the mixture (the line in Fig. 10). These were in good agreement with the experimentally obtained values of [fil/CfiOo]- [Pg.4109]

If a piece of nickel is suspended at a depth of 1 cm in an aqueous solution, what fraction of the intensity of the transition Ka, emitted when metal atoms are excited, will reach the surface Mass attenuation coefficients for hydrogen and oxygen are H 0.4 cm2/g O 13.8 cm2/g. [Pg.252]

The evaluation of the various XRF measurements will be discussed for different effects in EDXRS the spectra evaluation is perfonned by different programs with varying assumptions, partially different mass attenuation coefficients are used, the calibration procedures are principally different (e.g., thin foils with given thickness, or, infinitely thick samples), measurement under atmospheric pressure or in vacuum, secondary excitation (enhancement) mainly of Al by Si radiation. [Pg.411]

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