Monochromator hybrid

Henshall, M. and P. Held. 2008. Assay hybrid bridges microplate reader gap Synergy 4 combines features of filter- and monochromator-based systems. Genet. Eng. Biotechnol. News 28 (2). http//genengnews.com/ chtitem.aspx tid=2332 chid=l. 

As the heading implies, acquisition methods discussed in this section involve hybrids of multichannel and scanning techniques. Physically, they amount to a CCD on a scanning monochromator without an exit slit. As such, they are quite... 

For some specific applications, they can be associated with traditional monochromators. An illustration of a typical configuration of this kind is shown in Figure 2.16a. A parabohc artificial crystal is irradiated by a divergent source, and the beam diffracted by this element is then diffracted by a monochromator comprised of two or four plane crystals [SCH 95]. The beam resulting from this system, sometimes referred to as a hybrid monochromator, is perfectly monochromatic and much more intense than in the absence of a parabolic artificial crystal. Note, however, that this beam is much wider than the initial beam produced by the source. Therefore, this monochromator is only used for particular types of configurations and these hybrid monochromators are essentially used for certain studies of epitaxial thin films [STO 97]. 

Diffractometer in parallel geometry. Hybrid front monochromator and flat analyzer crystal... 

To determine the structural parameters of these M-plane MQWs by HRXRD, we follow the same procedure as employed in Ref. 67. Symmetric X-ray o)-20 scans were taken with a Philips X Pert PRO triple-axis diffractometer with a GuXai source, a Ge(220) hybrid monochromator, and a Ge(220) three-bounce analyzer crystal. We first analyzed the angular positions of the satellite peaks kinematically based on the nominal growth times to obtain the structural parameters of the sample, implicitly assuming that segregation does not occur. Next, we employed simulations based on the dynamical diffraction theory [67] and varied the kinematically obtained parameters, until the intensity of the satellites matched the experiment in addition to their position. The simulations were performed for perfect interfaces and are convoluted with the instrumental resolution (25 ) only. As an example. Figure 6.15 shows (o-20 scans for sample MQW-A across the (a) GaN(nOO) and (h) GaN(2200) reflection. 

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