Enhanced directional extraction of very cold neutrons using a diamond nanoparticle powder reflector

For more than a decade, detonation nanodiamond (DND) powders have been actively studied as a material for efficient reflectors of very cold neutrons (VCNs) and cold neutrons. In this work, we experimentally demonstrate, for the first time, the possibility of enhanced directional extraction of a VCN beam using a reflector made of fluorinated DND powder. With respect to the theoretical flux calculated from an isotropic source at the bottom of the reflector cavity, the gain in the VCN flux density along the beam axis is similar to 10 for the neutron velocities of similar to 57 and similar to 75 m/s. The use of such reflectors for enhanced directional extraction of VCN from neutron sources will make it possible to noticeably increase the neutron fluxes delivered to experiments and expand the scope of VCN applications.

Automated summary

This study demonstrates, for the first time, the possibility of enhanced directional extraction of very cold neutron beams using a reflector made of fluorinated detonation nanodiamond (DND) powder. This could significantly increase neutron fluxes in experiments and expand the applications of very cold neutrons.