Radiation Shielding calculations using MCNPX transport code for cost optimization of the shielding material to be used at iThemba LABS.

Abstract
At iThemba Laboratory for Accelerator Based Sciences (iThemba LABS), the shared use of the Separated Sector Cyclotron has reached the point where further advancement of the respective disciplines cannot be realised. The new facility is proposed to respond to the demands of these, specifically a phased development of Radioactive Ion Beam (RIBs). This facility will include a 70 MeV negative-ion cyclotron with the development of 5 Radioisotope production stations and two production stations for RIBs for nuclear physics and materials science research. The RIB Demonstrator project is suggested to test and demonstrate the advantages of the overall RIB project. The new cyclotron accelerator, which will provide currents of up to 350 μA of 70 MeV protons, has a potential of producing strong sources of ionising radiation. The most challenging entities, which are part of the indirect ionising radiation, are neutral neutrons and photons. There is a need to protect humans and materials from ionising radiation by providing adequate shielding to attenuate these particles, thus bringing their flux to acceptably low levels determined by the International Commission on Radiation Protection (ICRP) for designated personnel accessing this facility. The Monte Carlo for Neutral Particles eXtended (MCNPX) code was used for the purpose of investigating the correct thickness of the shielding of the cyclotron vault and the RIB Demonstrator vault. Results obtained confirmed that 4m and 3m thicknesses of concrete shielding will be adequate in the proposed cyclotron vault and RIB Demonstrator vault respectively.
Description
A Dissertation submitted for partial fulfilment of the requirements for the degree of Master of Science at the University of Zululand in the Department of Physics and Engineering at the University of Zululand, South Africa, 2012.
Keywords
Separated Sector Cyclotron, Radioactive Ion Beam
Citation