Characteristic radiation wavelength table

XRF spectra were broadly studied by H.G. J. Moseley who confirmed, in 1913-1914, the relationship between the wavelength of characteristic radiation and the atomic number, Z, of the radiation of the emitting anode material (see Table 4.6). Moseley found experimentally that the Ka lines for various anode materials exhibit the empirical relationship ... 

Table 1 depicts the main light sources used in artificial weathering tests and their characteristic wavelengths. Table 2 shows typical photochemical terms and their corresponding measurement units. Table 3 gives a detailed global radiation spectral distribution. 

The basis of this technique is absorption of ir radiation by molecules over a wide spectrum of wavelengths to give a characteristic fingerprint spectrum providing both qualitative and quantitative data on the substance. This versatile technique owes its success in occupational hygiene to the development of a portable spectrometer. Table 9.8 lists some compounds detectable by one type of portable ir analyser. 

X-ray fluorescence analysis is a nondestructive method to analyze rubber materials qualitatively and quantitatively. It is used for the identification as well as for the determination of the concentration of all elements from fluorine through the remainder of the periodic table in their various combinations. X-rays of high intensity irradiate the solid, powder, or liquid specimen. Hence, the elements in the specimen emit X-ray fluorescence radiation of wavelengths characteristic to each element. By reflection from an analyzing crystal, this radiation is dispersed into characteristic spectral lines. The position and intensity of these lines are measured. 

Vol. III. Physical and Chemical Tables (1962). Includes data on characteristic wavelengths, absorption coefficients, atomic scattering factors, Compton scattering, etc. Also treatments of intensity measurements, texture determination, particle size broadening, small angle scattering, and radiation hazards. 

In fluorescence spectrometry, the intensity of fluorescence is proportional to the intensity of the radiation source (see Section 16.15). Various continuum UV sources are used to excite fluorescence (see below). But the use of lasers has gained in importance because these monochromatic radiation sources can have high relative intensities. Table 16.5 lists the wavelength and power characteristics of some common laser sources. Only those that lase in the ultraviolet region are generally useful for exciting fluorescence. The nitrogen laser (337.1 nm), which can only be operated in a pulsed mode (rather than continuous wave, or CW, mode), is useful... 

Armed with the empirical knowledge that each element in the periodic table has a characteristic spectmm, and that heating materials to a sufficiently high temperature dismpts all interatomic interactions, Bunsen and Kirchoff invented the spectroscope, an instrument that atomizes substances in a flame and then records their emission spectmm. Using this instmment, the elemental composition of several compounds and minerals were deduced by measuring the wavelength of radiation that they emit. In addition, this new science led to the discovery of elements, notably caesium and mbidium. 

The shortest wavelength K lines are usually used for analysis, that is, K = 6.155 A, Kp = 5.804 A and Cr K radiation (2.29 A) is a suitable source of excitation. The K lines of P are easily distinguished from those of Si or S (Table 14.5). The sensitivity of the method is generally quite high, but it varies considerably depending upon the nature of the matrix. The latter can affect the intensity of characteristic x-ray emission and appropriate corrections have to be made. In the case of an iron matrix, the limits of detection are about 300 ppm, but in mineral oils the element can be detected in... 

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