PHYS01200804001 Sohrab Abbas - Homi Bhabha National Institute

CONTENTS
Page No.
SYNOPSIS
I-V
LIST OF FIGURES
Fig.1 Change in thermal neutron flux with time. Since 1970s, the neutron flux in research
Reactors got stagnated due to technical limitations over the achievable power
density, forcing to look for new types of neutron sources like spallation, fusion etc.
[14]. 2
Fig.2 The distribution of scattering lengths as a function of atomic mass number A
[5,119]. 14
Fig.3 Reciprocal space representation of the Bragg diffraction in a single crystal. 18
Fig.4 Asymmetric (a) Bragg and (b) Laue configurations of neutron incidence on a single
crystal. 20
Fig.5 Reciprocal space diagram of the Laue diffraction in a single crystal. 25
Fig.6 The intensities of the forward (I O ) and diffracted (I H ) beams exiting a parallel face
crystal slab in the symmetric Laue configuration as a function of the reduced
incidence angle y for the slab thickness t = 20.25 Δ S [4]. 30
Fig.7 Operating principle of a symmetric LLL IFM. 31
Fig.8 Intensities of the forward (O) anddiffracted (H) beams emerging from a symmetric
LLL interferometer (t S =t M =t A =t=20.25Δ S ) as a function of the reduced incidence
angle y for χ = 0 (solid curves) and χ = π (dashed curves) [4]. 34
Fig.9 Neutron propagation through amorphous and single crystal prisms. For the single
crystal prism, additional beams emerge from
front and side faces and the
transmitted beam undergoes a significant lateral displacement. 36