Simulation on Neutron Imaging Facility Based on 30 MeV Cyclotron Dian Adi Prastowo, Fahrurrozi Akbar, Andeka Tris Susanto, Rissa Damayanti, Anas Fahmi Imron, Haryo Seno, Rasito, Ridwan, Mujamilah, Abu Khalid Rivai
Research Center for Nuclear Beam Analysis Technology
National Research and Innovation Agency of Indonesia
Abstract
A new research facility based on 30-MeV cyclotron is now being developed at the National Research and Innovation Agency (BRIN) of Indonesia. One of the instruments at this facility will be neutron imaging (NI). This study aims to design an optimal neutron delivery system for NI using the Particle and Heavy Ion Transport code System (PHITS). The cyclotron accelerates 30 uA protons up to 30 MeV and then subsequently bombarded these protons onto a beryllium target. The neutrons then are moderated by high-density polyethylene. The beamtube is 1-meter long and is constructed based on the refined version of the existing neutron imaging facility at BRIN^s G.A. Siwabessy Research Reactor. Through simulations, we investigated the influence of different reflector and filter materials on the neutron flux. At the start of the beam tube, the overall neutron flux is 3.74 x 10^6 neutrons/(cm^2.s), of which 42.7% are thermal. Our findings suggest that an aluminium reflector coupled with a 5-cm thick graphite filter is the most effective configuration for minimizing neutron flux loss. This configuration delivers 1.5 x 10^4 thermal neutrons/(cm^2.s), which is 69.02% of overall neutrons exiting the beam tube. This number is comparable to other thermal neutron radiography facilities worldwide.
