EPJ Web Conf.
Volume 247, 2021PHYSOR2020 – International Conference on Physics of Reactors: Transition to a Scalable Nuclear Future
|Number of page(s)||8|
|Section||Research Reactors and Facilities|
|Published online||22 February 2021|
FACILITIES FOR NANO MATERIALS EXAMINATION AT THE PULSTAR REACTOR
Nuclear Reactor Program, Department of Nuclear Engineering North Carolina State University, Raleigh, NC 27695, USA
Published online: 22 February 2021
The PULSTAR is a 1-MWth nuclear research reactor located at North Carolina State University. It is fueled by uranium dioxide assemblies enriched to 4% or 6% in U-235 and is currently under licensing for operation at 2-MWth power. The PULSTAR is a center for irradiation testing and pre/post irradiation examination of materials. Among its unique capabilities are positron annihilation spectroscopy (PAS) and neutron powder diffraction (NPD) facilities. The PAS facility provides an intense positron beam reaching 6 × 108 e+/s, which drives two spectrometers; the e+-PAS and the Ps-PAS, used for studies of defects in thin film materials. A Na-22 bulk PAS system is also operational, which is used for studying millimeter scale materials. All spectrometers are capable of performing Doppler Broadening Spectroscopy (DBS) and Positron Annihilation Lifetime Spectroscopy (PALS). To date, the PAS systems have been used to characterize various materials (unirradiated and irradiated) that include graphite, soft matter, and metal-organic frameworks (MOF). The NPD facility uses a double focusing single crystal silicon rotating monochromator producing neutron beams with different energies. A position sensitive detection bank covers a scattering angle of 5°-125°. The facility is used in the examination of unirradiated and irradiated materials including graphitic materials, magnetic materials without rare-earth elements, and anode materials used in lithium batteries. The collected diffraction patterns can be processed to produce atomic pair distribution functions. The PAS and NPD facilities are available through user programs including the US DOE’s Nuclear Science User Facilities (NSUF) and the US NSF’s Research Triangle Nanotechnology Network (RTNN).
Key words: PULSTAR / nuclear reactor / positron annihilation / neutron diffraction / nanotechnology
© The Authors, published by EDP Sciences, 2021
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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