Cameras small-angle

The X-ray instrumentation requires a commercial small angle X-ray camera, a standard fine structure X-ray generator and a sample manipulator if scanning is requested. The essential signal is the relative difference between the refraction level Ir and the absorption level Ia. Both levels are measured simultaneously by two scintillation detectors. At fixed angles of deflection this signal depends solely on the inner surface density factor C and thickness d of the sample [2] ... 

A Siemens Kratky camera system was utilized for small angle x-ray scattering (SAXS) measurements in conjunction with an M. Braun position sensitive detector from Innovative Technology Inc.. Wide angle x-ray diffraction was obtained utilizing a Philips table-top x-ray generator. 

SAXS Small angle diffraction patterns were obtained a room temperature using a "Searle" X-ray camera with Cu Ka (1.54A) radiation (35 kV, 25 mA). The exposure times were about 65 hours. 

For small angle scattering, Statton or equivalent camera... 

Methods. The wide and small angle x-ray patterns were recorded in a flat film camera at controlled relative humidity using Ni-filtered CuKa radiation generated at 40 kV and 15 mA. 

Laue and Warhus cameras were used for the side-angle and small-angle photographs respectively. The stress-strain data were obtained on an electrohydraulic deformation apparatus especially built for Xerox by MTS Systems Corp. (18). Tensile engineering stress-strain data was obtained at 30°C and a strain rate of 0.1 in./in./min. 

The polymerized sample in the capillary was examined with the modified atky Small-Angle X-Ray camera at the UnivCTsity of Minnesota. Due to beam-time limitations (five hours, at 1000 Watts of Cu radiation), the statistics in the data are... 

Types of Synchrotron Radiation Small-Angle Scattering Cameras... 

Fig. 20. Schematic design of an energy-dispersive small-angle scattering camera A Beryllium window separates the vacuum of the storage ring from the experimental section. The polychromatic beam is collimated prior to the sample. The scattered radiation is recorded under a constant 29-angle by a Silicon-detector...

The optics of angular dispersive small angle scattering cameras differ according to the field of application. Thus the double monochromator camera is mainly used for anomalous dispersion experiments (Fig. 21) By varying the Bragg angle of two... 

Hg. 21. Schematic design of a double monochromator small-angle scattering camera. The first monochromator is at 24 m from the source. I denotes two ionization chambers. No focussing elements are used... 

In polymer research the information which can be obtained from small angle and wide angle scattering is often complimentary (see Sect. 4) which suggests to use a small angle scattering camera for both types of experiments. Practical arguments like the... 

Fig. 27. Geometry of a focussing small angle scattering camera after the focussing elements. The resolution is limited by the intense background which is due to scattering from the aperture sUt. The guard slit only limits the diffuse scattering without cutting into the primary beam...

Fig. 28. Calculation of the vertical resolution -L- of a small angle scattering camera. Lj corresponds to the distance of the guard slit to the detector plane (see Fig. 27). The other parameters are indicated in the text...

A considerably higher resolution is expected for a small angle scattering camera at a dedicated source like the NSLS at Brookhaven or the projected ESRF which is due to a smaller source point, a smaller vertical divergence and an optimum location of the optical elements. 

One is limited, however, by the angle of critical reflection as the intensity decreases with increasing angle of total reflection. From this point of view a mirror with heavy atom coating is preferable over a quartz mirror. In view of the use as a small angle scattering camera, low electron density materials have, however, been preferred (Sect. 3.2.2). 

The experimental equipment requires a standard fine structure X-ray generator operated usually with monochromatic K -radiation. The measurements of the refraction effect are taken by using a commercial small angle X-ray camera of the Kratky type in combination with two scintillation detectors for simultaneous detection of X-ray refraction intensity Ir and sample absorption U- A standard DOS-computer handles the scattering intensity data acquisition and the micromanipulator scanning-system. Figure 1 shows the experimental setup. 

Small angle X-ray scattering (SAXS) was measured with a Kratky camera using nickel filtered CuKa radiation. The width of the entrance and detector slits were 20 and 50 pm, respectively. No desmearing procedure was applied to the scattering curves. Absolute measurements were carried out by using a Lupolen standard. 

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