Gaussian line element

The net result of these considerations is that, for a spectrum of Gaussian lines, one should sample 10 times per resolution element ( FWHM of isolated lines) and that the scan rate should be adjusted to yield a scan rate of 10 times constants to scan one resolution element (Blass, 1976a). 

The results in Table 8 indicate that the chemical effect on the KP/Ka ratios is in order of several %. This means that the experimental studies on this effect should be made very carefully. In all experiments except for two, Paci-Mazzilli and Urch [20] and Mukoyama et al [26], Si(Li) detectors were used to observe x-ray spectra. Owing to poor energy resolution of the solid-state detectors, K(3 satellite peaks cannot be resolved from the K 3, z diagram line and the presence of these peaks should be taken into account in the data analysis of the experimental spectra. However, a single Gaussian shape has often been used for the Kf3 composite peak in most experiments. In order to compare with the present theoretical values, it is hoped that more systematic studies for the chemical effect on the K /Ka ratios for 3d elements be performed with high... 

The present results seems to indicate that the dependence of the excitation mode on the K 0 /K oc ratios is difficult to observe experimentally. However, it should be noted that all the experimental values discussed above were measured with SSD, such as Si(Li) and Ge(Li) detectors, and obtained by assuming single Gaussian shape for Ka and K 0 x-ray peaks. We have already pointed out (15) that the chemical effect on the K0 Ka intensity ratios in 7>d elements is sensitive to the intensities of K0 and K0peaks, which cannot be observed separately with SSD. This means that if these peaks are measured separately from the K013 diagram line, it may be possible to detect the difference due to excitation modes more clearly. 

Figure 10.26. Experimental excitation profiles for the double pulsed field gradient spin-echo excitation sequences in which the element S is either a 180° Gaussian pulse (truncated at 1%) or a 180° Q3 pulse of the durations shown. Line spacings are 5 Hz.

Fig. 4. Coding power for a URA-based mask with square elements of size m viewed by a detector with square pixels of side d as a function of the ratio Q = mid. The corresponding curve for a continuous detector is plotted as a dotted line, using Q = m/(2 /3u ) where w is the a of the Gaussian function describing the detector resolution. The numerical factor l(2y/Z) is the rms uncertainty in a variable which is known to plus or minus half a pixel.

A system of coordinates, i.e. x, y, is defined on the middle surface, so that the lines X = const meets lines y = const at right angles (Gaussian coordinates). The element is out from the shell along pairs of adjacent coordinates lines, and the cuts are made so that four sides of the element are normal to the middle surface. The coordinates z is measured positive inwards, x, y, z, from a right-handed triad. 

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