Multiple-wavelength neutron holography with pulsed neutrons
نویسندگان
چکیده
Local structures around impurities in solids provide important information for understanding the mechanisms of material functions, because most of them are controlled by dopants. For this purpose, the x-ray absorption fine structure method, which provides radial distribution functions around specific elements, is most widely used. However, a similar method using neutron techniques has not yet been developed. If one can establish a method of local structural analysis with neutrons, then a new frontier of materials science can be explored owing to the specific nature of neutron scattering-that is, its high sensitivity to light elements and magnetic moments. Multiple-wavelength neutron holography using the time-of-flight technique with pulsed neutrons has great potential to realize this. We demonstrated multiple-wavelength neutron holography using a Eu-doped CaF2 single crystal and obtained a clear three-dimensional atomic image around trivalent Eu substituted for divalent Ca, revealing an interesting feature of the local structure that allows it to maintain charge neutrality. The new holography technique is expected to provide new information on local structures using the neutron technique.
منابع مشابه
Measurement of the Deli,.yed Neutron Fraction and Correction of Small Angle Scattering Data from a Pulsed Spallation Source
The fraction of delayed neutrons in a moderated beam from the enriched uranium, pulsed spallation source at the intense pulsed neutron source at Argonne National Laboratory has been measured and found to be 0.0283 for 450-MeV protons. Delayed neutrons produce a sample-dependent background in time-of-flight instruments . Because of the distribution of neutron wavelengths in the prompt pulse, the...
متن کاملFinal design of the Energy-Resolved Neutron Imaging System “RADEN” at J-PARC
A new pulsed-neutron instrument, named the Energy-Resolved Neutron Imaging System “RADEN”, has been constructed at the beam line of BL22 in the Materials and Life Science Experimental Facility (MLF) of J-PARC. The primary purpose of this instrument is to perform energy-resolved neutron imaging experiments through the effective utilization of the pulsed nature of the neutron beam, making this th...
متن کاملNeutron-optical gratings from nanoparticle-polymer composites
The preparation of neutron-optical phase gratings with light-optical holography is reviewed. We compare the relevant concepts of: (i) Kogelnik’s theory for Bragg diffraction of light by thick volume gratings, which can be used to analyze holographic gratings with both light and neutrons, and (ii) the dynamical theory of neutron diffraction. Without going into mathematical detail, we intend to i...
متن کاملParameters of the NERA spectrometer for cold and thermal moderators of the IBR-2 pulsed reactor
The inverted geometry time-of-flight spectrometer NERA designed for simultaneous investigation of elastic and inelastic neutron scattering was constructed on a 100 meter long flight path of the IBR-2 reactor at JINR, Dubna, Russia. Spectrometer parameters were optimized for the thermal neutron spectrum of a water moderator at 330 K. Recently, a new type of cold neutron source operating at 30 K ...
متن کامل