title: Interference fringes in multiple Bragg-Laue mode.
abstract: Interference fringes in multiple Bragg-Laue mode have been measured from the lateral surface of an Si plane-parallel crystal by changing the distance L between the incident point of X-rays and the crystal edge for two sample crystals with different thicknesses H. The period of the interference fringes becomes large when the distance L becomes large or the thickness H becomes small. When the ratio L/H is larger than 15, a shorter period of oscillation appears in addition to the interference fringes. These variations are explained by considering the beams in multiple Bragg-Laue modes based on the dynamical theory of diffraction. When L/H is less than 15, the measured fringes are well reproduced by taking account of interference between beams in the Bragg-Laue and the Bragg-Bragg-Laue modes. The short period of the oscillations observed for L/H > 15 is reproduced by adding the intensities of the beams in higher-order Bragg-Laue mode. The interference fringes calculated by taking the visibility into account show good agreement with the measured ones.
authors.affiliation: Saitama Institute of Technology, 1690 Fusaiji, Fukaya, Saitama 369-0293, Japan. tomoe@sit.ac.jp
authors.forename: Tomoe
authors.initials: T
authors.lastname: Fukamachi
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirano
authors.forename: Riichirou
authors.initials: R
authors.lastname: Negishi
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Kanematsu
authors.forename: Sukswat
authors.initials: S
authors.lastname: Jongsukswat
authors.forename: Keiichi
authors.initials: K
authors.lastname: Hirano
authors.forename: Takaaki
authors.initials: T
authors.lastname: Kawamura