Tagging fast neutrons from a 252 Cf fission-fragment source

Abstract

Coincidence and time-of-flight measurement techniques are employed to tag fission neutrons emitted from a Cf source sealed on one side with a very thin layer of Au. The source is positioned within a gaseousHe scintillator detector. Together with α particles, both light and heavy fission fragments pass through the thin layer of Au and are detected. The fragments enable the corresponding fission neutrons, which are detected in a NE-213 liquid-scintillator detector, to be tagged. The resulting continuous polychromatic beam of tagged neutrons has an energy dependence that agrees qualitatively with expectations. We anticipate that this technique will provide a cost-effective means for the characterization of neutron-detector efficiency in the energy range 1-6MeV.

GEANT4-based calibration of an organic liquid scintillator

“…The operating voltage of the detector was set at −2 kV, a voltage employed for this detector in previous VME setups [13][14][15][16][17]. At this voltage, a 1 MeV ee signal had a risetime of ∼5 ns, an amplitude of ∼900 mV and a falltime of ∼60 ns.…”

From micro- to macro- neutron sources: The Lund Broad-band Neutron Facility

“…At the LBNF, these beams have been successfully used for response characterizations of neutron detectors [2,3,4] and their data-acquisition systems [5]. Using a technique called "tagging" and the infrastructure present at the LBNF, it is even possible to study attenuation and detector responses as function of the neutron energy even with standard radioactive sources [6,7,8]. Based on coincidence measurements between prompt gamma-ray emissions and the neutron in the reaction α + 9 Be → 12 C * + n → 12 C + γ + n which are present in around 55% of all decays, one can determine the time of flight of the neutron on an event-by-event basis.…”

Development and characterization of detectors for large area application in neutron scattering and small area application in neutron reflectometry

“…For incident neutron in the thermal energies, only the s-wave capture will occur, for which I = I ± 1 2 and π = π. A very interesting radiative capture process is the one of Gadolinium; the cross section for thermal neutron capture is about 2.5 • 10 5 barns in 157 Gd, one of the largest nuclear cross section in any material. This isotope is 15.7% abundant in natural Gadolinium, and upon neutron absorption in Gd, γ-rays over a wide keV energy range, and a cascade of conversion electrons with an energy spectrum extending from 20-30 keV up to ∼250 keV, with a main peak at about 70 keV [28,29,30], are emitted.…”