A HIGH-TEMPERATURE BONSE-HART ULTRASMALL-ANGLE X-RAY-SCATTERING INSTRUMENT

A Bonse-Hart ultrasmall-angle x-ray scattering (USAXS) instrument has been designed, constructed, and tested employing a synchrotron x-ray s ource. The instrument permits experiments ranging from below 0-degrees -C up to about 400-degrees-C, as well as temperature scanning, jumping , quenching, and annealing experiments. The mechanical elements used S uper Invar as the basic building material in order to minimize the the rmal expansion effect. As the synchrotron beam after the beamline opti cs is already somewhat collimated and monochromatized, a very fine tun ing of the first crystal was necessary. The high-temperature Bonse-Har t instrument increased the performance by a factor of about 10 when co mpared with our earlier room-temperature Bonse-Hart instrument using t he same set of channel-cut germanium crystals. The instrument was test ed by using a suspension of polystyrene latex spheres and by combining the USAXS measurement, for the first time, with measurements of the s ame latex suspension by means of laser light scattering.