主 题: Neutron Phase Imaging with Gratings
报告人: Seung Wook LEE, Ph.D. (Korea Atomic Energy Research Institute)
时 间: 2009-09-15 下午15:00
地 点: 理科一号楼 1568
Recently, it has been demonstrated that a shearing type interferometer,
using precision silicon gratings, enables one to image the gradient of
neutron phase shift through an object and retrieve the phase via a
simple one-dimensional integration of the gradient. To fully explore
this new technique for potential future cold neutron imaging stations at
the National Institute of Standards and Technology and the Korea Atomic
Energy Research Institute, we have developed a prototype phase imaging
station at a monochromatic cold neutron beamline in the NCNR neutron
guide hall [1] and at the ex-core neutron irradiation facility at
HANARO. We have designed the silicon gratings for a neutron wavelength
of 0.44 nm and fabricated them using the state-of-the-art
nanofabrication facility at the NIST Center for Nanoscale Science and
Technology.
In this talk, we will discuss the experimental apparatus, as well as the
recent experimental results obtained with this prototype apparatus. We
will also present the data analysis method used for the phase retrieval,
and discuss the accuracy of the method as well as the measurement
sensitivity obtained using this method. A possibility to apply this new
technique to visualize the magnetic domain structure in electrical
steels will be presented with a few preliminary data.
[1] S.W. Lee, D.S. Hussey, D.L. Jacobson, C.M.Sim, M. Arif, “Development
of the grating phase neutron interferometer at a monochromatic beam
line”, Nuclear Instruments and Methods in Physics Research Section A:
Accelerators, Spectrometers, Detectors and Associated Equipment (2009),
doi:10.1016/j.nima.2009.01.225
