Broad spectrum moderators and advanced reflector filters using (208)pb

• Cold and thermal neutrons used in neutrons scattering experiments are produced in nuclear reactors and spallation sources. The neutrons are cooled to thermal or cold temperatures in thermal and cold moderators, respectively. The present study shows that it is possible to exploit the poor thermalizing property of Pb-208 to design a broad spectrum moderator, i.e. a moderator which emits thermal and cold neutrons from the same position. Using Pb-208 as a reflector filter material is shown to be slightly less efficient than a conventional beryllium reflector filter. However, when surrounding the reflector filter by a cold moderator it is possible to regain the neutrons with wavelengths below the Bragg edge, which are suppressed in the beryllium reflector filter. In both the beryllium and lead case surrounding the reflector filter with a cold moderator increases the cold brightness significantly compared to a conventional reflector filter. (C) 2014 Elsevier B.V. All rights reserved.

Ämnesord

NATURVETENSKAP  -- Fysik -- Acceleratorfysik och instrumentering (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Accelerator Physics and Instrumentation (hsv//eng)

Nyckelord

Spallation

Neutron

Moderators

Reflector filter

Rispectral

Neutronics

Publikations- och innehållstyp

art (ämneskategori)

ref (ämneskategori)