In-Situ Analysis of Corrosion Products in Molten Salt: X-ray Absorption Reveals Both Ionic and Metallic Species.

Understanding and controlling the chemical processes between molten salts and alloys is vital for the safe operation of molten-salt nuclear reactors. Corrosion processes in molten salts are highly dependent on the redox potential of the solution that changes with the presence of fission and corrosion processes, and as such, reactor designers develop electrochemical methods to monitor the salt. However, electrochemical techniques rely on the deconvolution of broad peaks, a process that may be imprecise in the presence of multiple species that emerge during reactor operation.

Design of a neutron microscope based on Wolter mirrors.

The predominant geometry for a neutron imaging experiment is that of a pinhole camera. This is primarily due to the difficulty in focusing neutrons due to the weak refractive index, which is also strongly chromatic. Proof of concept experiments demonstrated that neutron image forming lenses based on reflective Wolter mirrors can produce quantitative, high spatial resolution neutron images while also increasing the time resolution compared to the conventional pinhole camera geometry.

Design of Neutron Microscopes Equipped with Wolter Mirror Condenser and Objective Optics for High-Fidelity Imaging and Beam Transport.

We present and compare the designs of three types of neutron microscopes for high-resolution neutron imaging. Like optical microscopes, and unlike standard neutron imaging instruments, these microscopes have both condenser and image-forming objective optics. The optics are glancing-incidence axisymmetric mirrors and therefore suitable for polychromatic neutron beams.

High-resolution neutron depolarization microscopy of the ferromagnetic transitions in NiAl and HgCrSe under pressure.

We performed neutron imaging of ferromagnetic transitions in NiAl and HgCrSe crystals. These neutron depolarization measurements revealed bulk magnetic inhomogeneities in the ferromagnetic transition temperature with spatial resolution of about 100 μm. To obtain such spatial resolution, we employed a novel neutron microscope equipped with Wolter mirrors as a neutron image-forming lens and a focusing neutron guide as a neutron condenser lens.

Demonstration of a novel focusing small-angle neutron scattering instrument equipped with axisymmetric mirrors.

Small-angle neutron scattering (SANS) is the most significant neutron technique in terms of impact on science and engineering. However, the basic design of SANS facilities has not changed since the technique's inception about 40 years ago, as all SANS instruments, save a few, are still designed as pinhole cameras. Here we demonstrate a novel concept for a SANS instrument based on axisymmetric focusing mirrors.