Design of Moderator Neutron for Boron Neutron Capture Therapy in Kartini Nuclear Reactor Using Monte Carlo N Particle 5 Simulation

The optimation of moderator design on radial piercing beam port in Kartini Nuclear Reactor using MCNP5 simulation has been carried out. This optimation has been used for obtaining neutron flux according to International Atomic Energy Agency (IAEA) regulation. The methode used in this experiment was combination of shifting methode and filtering methode. Independent variables varied, were material and thickness of collimator wall, moderator, filter and gamma shielding. Optimized epithermal neutron flux of the collimator for BNCT has been achieved 1.20 × 10¹ n/cm²s. The result of beam quality are 0.8 for neutron current component, 0.03 for thermal neutron component, 312 × 10^-13 Gy cm²s/n for fast neutron component and 38.5 × 10^-13 Gy cm²s/n for gamma contamination component. It can be concluded that, the designed moderator is feasible and applicable for BNCT. (paper)