Optimizing the moderator geometry and thickness for a reactor-based slow positron source

Effect of neutron–photon converter materials (Cd, Gd, and Sm) on the positron production in a reactor-based slow positron beamline

“…Therefore, the operation and/or the new construction of intense slow positron beam facilities using nuclear reactors as a positron source are being promoted in many countries [13,14,15,16,17,18,19,20,21,22,23,24]. Experimental and simulation studies on positron moderation for a reactor-based positron source were also conducted [16,25]. In reactor-based slow positron beamlines, a neutron-photon converter made of cadmium (Cd) is commonly used to improve the intensity of gamma-ray photons required for the positron pair production [13,14,15,16,17,18,19,20,21].…”