title: Non-Destructive Study of Bulk Crystallinity and Elemental Composition of Natural Gold Single Crystal Samples by Energy-Resolved Neutron Imaging.
abstract: Energy-resolved neutron imaging enables non-destructive analyses of bulk structure and elemental composition, which can be resolved with high spatial resolution at bright pulsed spallation neutron sources due to recent developments and improvements of neutron counting detectors. This technique, suitable for many applications, is demonstrated here with a specific study of ~5-10 mm thick natural gold samples. Through the analysis of neutron absorption resonances the spatial distribution of palladium (with average elemental concentration of ~0.4 atom% and ~5 atom%) is mapped within the gold samples. At the same time, the analysis of coherent neutron scattering in the thermal and cold energy regimes reveals which samples have a single-crystalline bulk structure through the entire sample volume. A spatially resolved analysis is possible because neutron transmission spectra are measured simultaneously on each detector pixel in the epithermal, thermal and cold energy ranges. With a pixel size of 55 μm and a detector-area of 512 by 512 pixels, a total of 262,144 neutron transmission spectra are measured concurrently. The results of our experiments indicate that high resolution energy-resolved neutron imaging is a very attractive analytical technique in cases where other conventional non-destructive methods are ineffective due to sample opacity.
authors.affiliation: Space Sciences Laboratory, University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720, USA.
authors.forename: Anton S
authors.initials: AS
authors.lastname: Tremsin
authors.affiliation: Department of Geology and Environmental Earth Science, Miami University, 250 South Patterson Ave., Oxford, OH 45056, USA.
authors.forename: John
authors.initials: J
authors.lastname: Rakovan
authors.affiliation: Japan Atomic Energy Agency, 2-4 Shirakata-shirane Tokai-mura, Naka-gun Ibaraki 319-1195, Japan.
authors.forename: Takenao
authors.initials: T
authors.lastname: Shinohara
authors.affiliation: STFC-Rutherford Appleton Laboratory, ISIS Facility, Didcot, OX11 0QX, UK.
authors.forename: Winfried
authors.initials: W
authors.lastname: Kockelmann
authors.affiliation: Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
authors.forename: Adrian S
authors.initials: AS
authors.lastname: Losko
authors.affiliation: Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
authors.forename: Sven C
authors.initials: SC
authors.lastname: Vogel