Evaluation of fast neutron shielding effectiveness in light-element compounds

Fast neutron shielding has important applications in accelerator facilities, reactor technology, space radiation protection programs, and in minimizing the dose in radiation facilities. Due to their ability to reduce neutron energy and their high absorption cross sections, lightweight and low atomic number (Z) materials that contain neutron absorbers are the de facto choice for shielding against fast neutrons. Thus, an optimized concentration of neutron absorbers relative to the hydrogen content may make a difference in the effectiveness of any shielding material. The superiority of such an approach lies in its capability to moderate neutrons via scattering process interaction with hydrogen after a small number of collisions and sooner or later their absorption by the incorporated neutron absorbers. This study aims to investigate the shielding effectiveness against fast neutrons of some relatively new materials such as Borated Polyethylene (BPE) and some innovative materials such as Lithium Hydride (LiH), which contain not only light elements but also incorporate an optimized concentration of hydrogen visa-vis neutron absorbers. The study examines the effect of varying moderator/absorber ratios on the dose transmission factor. A series of experiments were carried out using a 2.5 MeV D-D neutron generator at 106 n/s intensity along with MCNPX and PHITS code simulations. The transmission factor in different experiments was found to vary from 11% up to 34% with increasing thickness. Simulation results were in reasonable agreement with experimental data and supported the conclusion that hydrogen content is the determining factor in reducing dose transmission.

Name thesis:degree_name

Master of Applied Science (MASc)

Discipline thesis:degree_discipline

Nuclear Engineering

Grantor

University of Ontario Institute of Technology

Year dc:date.issued

2024

Author dc:creator

• Tamimi, Eyad

Advisor dc:contributor.advisor

• Machrafi, Rachid

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10155/1907

OAI identifier oai:identifier

oai:ontariotechu.scholaris.ca:10155/1907