Slit system vs. radial collimators; Experimental study on KOWARI

Vladimir, L.*; Suzuki, Hiroshi  

The aim of our experimental research was to compare performance of the two systems, slit system and radial collimator, in typical applications. The study was carried out on Kowari diffractometer (OPAL research reactor, ANSTO) using two radial collimators temporary removed from RESA diffractometer (JRR-3, JAEA). A standard residual stress experiment was performed using both the radial collimators system with gauge volume 0.5, 3 and 5 mm and the slit system with the same gauge volume parameters. The performance of the both system was judged by comparing statistics precision, resolution and the effect of partial illumination in near-to-surface positions of the gauge volume. As a result, the large type radial collimator system is advantage in strain measurements of large samples to prevent bumping sample to optical devices, while the slit system is advantage in strain measurements in small samples to have good counting statistics.