Long Horizontal Parallel Slits with 0.03° Angular Resolution for Powder Diffraction Using Synchrotron Radiation

Long horizontal parallel slits with angular apertures of 0.032 and 0.065° were constructed for powder diffraction experiments with synchrotron radiation. They have been tested at the BL-4B experimental station at the Photon Factory by using a monochromated beam with a wavelength of 1.528 Å. The horizontal parallel slits with the smaller aperture gave a full-width at half-maximum of 0.030 (1)° for the (200) reflection from CeO₂ and an intensity about one order of magnitude higher than that obtained with a receiving slit in the same angular resolution, demonstrating the finest horizontal parallel slits developed so far. The misalignment of the horizontal parallel slits does not affect the intensity whilst it shifts the Bragg-peak positions systematically.