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![[Figure 9]](kv5088fig9mag.jpg)
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Figure 9
Example data obtained using the two techniques described in this work. (a) and (b) show, respectively, a detector image after background subtraction and azimuthally integrated data from an unreacted Al3Ni2 foil using the PAD at CHESS. (c) and (d) show, respectively, a raw detector image and azimuthally integrated data from an unreacted Al3Zr foil using the CCD camera and fast shutter at APS. In (c) the pale rectangle and line in the upper portion of the image is the shadow from the tungsten beamstop and the PIN diode arm. The pale rectangle in the lower left portion is the shadow from a lead tape mask placed on the detector face to block a strongly scattering peak from the PIN diode. The dark areas on the right side of the image result from air scattering upstream of the sample cassette. While differences in the experimental details and samples make a direct comparison difficult, the figure shows the improved signal-to-noise ratio, extended q-range collected and higher resolution achievable with the combination of the CCD camera and fast shutter at APS compared with the PAD at CHESS. The azimuthally integrated PAD data (b) are an average of six separate 50 µs exposures while the CCD data (d) are from a single 18 µs exposure. The breadth of the peaks is primarily due to the energy spread (∼2% in both cases) in the incident beams at each source (from the multilayer monochromator used at CHESS and the inherent energy spread in the undulator source at APS). The asymmetric shape of the peaks in the data taken at APS results from the asymmetric energy distribution of the beam from the undulator source at sector 7 at APS (see, for example, Skuza et al., 2007  ). |
![[Figure 9]](kv5088fig9.jpg)
 | JOURNAL OF SYNCHROTRON RADIATION |
ISSN: 1600-5775
