Schulz transmission method

The Schulz transmission method [9.10] involves the use of a divergent, rather than a parallel, incident beam and a counter slit narrow enough to intercept only the central portion of the diffracted beam. For these conditions Schulz derived an equation, analogous to Eq. (9-9), relating the intensity diffracted by a random specimen (for brevity random specimen will be written for specimen with randomly oriented grains ) to the angular setting a. He also showed that the intensity diffracted by a random specimen was constant within a few percent up to an a value of about 30° for a sufficiently thin specimen nt = 0.4 to 0.7) and small values of 6 (less than about 20°) under these conditions the correction equation is not needed. 

Figure 9-17 shows a specimen holder suitable for either transmission method and for the Schulz reflection method. 

Fig. 9-17 Pole-figure goniometer. The specimen shown is positioned for measurements by the transmission method, and a simple change in the orientation of the specimen holder allows measurements by the Schulz reflection method. The x-ray tube is seen here end-on. This instrument is designed for automatic operation. (Courtesy of Siemens Corporation.)...

In 1971 a new variation on the transmission method was introduced by Sanche and Schulz (13). The technique incorporated the trochoidal monochromator of Stamatovlc and Schulz (14) and a modulation scheme to obtain the derivative of the electron current transmitted through a gas cell. This combination provides a relatively simple and very sensitive means of locating resonances as they appear in the total scattering cross section. In particular the energy resolution (20-50 meV), which is substantially better than that found in most trapped electron and SFg scavenger studies, is sufficient to observe the vibrational structure possessed by anions long lived enough to... 

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