Radiotherapy Research Today is a free monthly online journal that collates and summarizes the latest research about Radiotherapy, including details on cancer treatment, side effects.

Benchmark experiments for cyclotron-based neutron source for BNCT.

Yonai S, Itoga T, Baba M, Nakamura T, Yokobori H, Tahara Y

Cyclotron and Radioisotope Center, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan. yonai@cyric.tohoku.ac.jp

In the previous study, we found the feasibility of a cyclotron-based BNCT using the Ta(p,n) neutrons at 90 degrees bombarded by 50 MeV protons, and the iron, AlF(3), Al and (6)LiF moderators by simulations using the MCNPX code. In order to validate the simulations to realize the cyclotron-based BNCT, we measured the epithermal neutron energy spectrum passing through the moderators with our new spectrometer consisting of a (3)He gas counter covered with a silicon rubber loaded with (nat)B and polyethylene moderator and the depth distribution of the reaction rates of (197)Au(n,gamma)(198)Au in an acrylic phantom set behind the rear surface of the moderators. The measured results were compared with the calculations using the MCNPX code. We obtained the good agreement between the calculations and measurements within approximately 10% for the neutron energy spectra and within approximately 20% for the depth distribution of the reaction rates of (197)Au(n,gamma)(198)Au in the phantom. The comparison clarified a good accuracy of the calculation of the neutron energy spectrum passing through the moderator and the thermalization in a phantom. These experimental results will be a good benchmark data to evaluate the accuracy of the calculation code.

Published 13 August 2004 in Appl Radiat Isot, 61(5): 997-1001.
Full-text of this article is available online (may require subscription).

© 2004-2008 Radiotherapy Research Today. All Rights Reserved.