Laser based neutron spectroscopy

Abstract

Great progress has been made in recent years in realizing compact, laser-based neutron generators. These devices, however, were inapplicable for conducting neutron absorption spectroscopy because of the electromagnetic noise produced by the interaction of a strong laser field with matter. To overcome this limitation, we developed a novel neutron time-of-flight detector, largely immune to electromagnetic noise. The detector is based on a plastic scintillator, only a few-millimeters in size, coupled with a silicon photo-multiplier by a long light-guiding fiber. Using this detector, we demonstrated for the first time laser-based fast neutron spectroscopy. This achievement paves the way to realizing compact neutron radiography systems for research, security, and commercial applications, and introduces new prospects for probing the temperature of matter under extreme conditions and for inertial confinement fusion diagnostics.