title: Improvement of beamline 4B9A and results of an X-ray diffraction experiment.
abstract: 4B9A is a focusing and monochromatic photon beam at the BSRF, which was constructed in 1990. During the second phase of the BSRF program, the surface of the cylindrical mirror has been coated with Pt, covering the original Ni, and the monochromator has been upgraded. The maximum photon energy extends to 11 keV and the intensity has increased about tenfold with respect to the previous intensity at 6 keV. Synchrotron X-ray diffraction patterns for the Hg-1223 (HgBa(2)Ca(2)Cu(3)O(8+delta)) superconducting bulk and thin film have been measured at 1.54014 A. Results indicate that the bulk and film can be indexed as possessing tetragonal symmetry; lattice parameters a = 3.856 A and c = 15.851 A for the bulk Hg-1223 compound, and a = 3.8517 A and c = 15.8511 A for the film. Their structures are similar.
authors.affiliation: BSRF, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039, People's Republic of China.
authors.forename: D W
authors.initials: DW
authors.lastname: Wang
authors.forename: H Y
authors.initials: HY
authors.lastname: Jiang
authors.forename: Z H
authors.initials: ZH
authors.lastname: Wu
authors.forename: X S
authors.initials: XS
authors.lastname: Wu
authors.forename: S S
authors.initials: SS
authors.lastname: Jiang
authors.forename: X X
authors.initials: XX
authors.lastname: Yao
authors.forename: H M
authors.initials: HM
authors.lastname: Shao
authors.forename: Y M
authors.initials: YM
authors.lastname: Cai
authors.forename: L J
authors.initials: LJ
authors.lastname: Shen
authors.forename: Z
authors.initials: Z
authors.lastname: Wu