Abstract. The HANARO ex-core neutron irradiation facility was developed for various applications in the boron neutron capture therapy (BNCT) field, and its characteristics have been investigated. In order to obtain a sufficient thermal neutron flux with a low level contamination of fast neutrons and gamma-rays, a radiation filtering method is adopted. The radiation filter has been designed by using a silicon single crystal cooled by liquid nitrogen and a bismuth crystal. The installation of the main components of the irradiation facility and the irradiation room are finished. Experimental measurements of the neutron beam characteristics have been performed by using bare and cadmium covered gold foils and wires. The in-phantom neutron flux distribution was measured for a flux mapping inside the phantom. The gamma-ray dose was determined by using TLD-700 thermoluminescence dosimeters. The thermal and fast neutron fluxes and the gamma-ray dose were calculated by using the MCNP code, and they were compared with experimental data. The thermal neutron flux and Cd ratio which can be obtained at this facility are 1.49×10 9 n/cm 2 s and 152, respectively. The maximum neutron flux inside the phantom was measured to be 2.79×10 9 n/cm 2 s at a depth of 3 mm in the phantom. The two-dimensional in-phantom neutron flux distribution was determined, and the significant neutron irradiation was observed within 20 mm from the phantom surface. The gamma-ray dose rate for the free beam condition is expected to be about 80 cGy/hr. These experimental results are reasonably well supported by the calculated values of the facility design code. This HANARO thermal neutron facility can be used not only for a clinical trial but also for various basic irradiation researches of the BNCT field.
The HANARO operated by KAERI(Korea Atomic Energy Research Institute) has two neutron radiography facilities which are called as the Neutron Radiography Facility(NRF) and the Boron Neutron Capture Therapy(BNCT) facility, respectively. For the researches on HANARO, the NRF was used to find a weld defect in the irradiation rig made from Al for NTD in HANARO. Also, the neutron radiography inspection at the NRF was very useful to find the root causes of a defect in the HANARO fuel. As for the use of the BNCT facility for dynamic neutron radiography, a calibration curve showing the relationship between the extent of the neutron attenuation and the thickness of the liquid in the channel is important and this curve was obtained experimentally and from a computer simulation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.