医学直线加速器中子能谱的研究。

A study of neutron spectra from medical linear accelerators.

作者信息

Facure A, Falcão R C, Silva A X, Crispim V R, Vitorelli J C

机构信息

Comissão Nacional de Energia Nuclear, R. Gal. Severiano 90, sala 405, 22294-900, Rio de Janeiro, RJ, Brazil.

出版信息

Appl Radiat Isot. 2005 Jan;62(1):69-72. doi: 10.1016/j.apradiso.2004.05.072.

DOI:10.1016/j.apradiso.2004.05.072

PMID:15498687

Abstract

Medical accelerators with photon energies over 10 MeV generate an undesired fast neutron contamination in the therapeutic beam. In this work, the Monte Carlo code MCNP was used to simulate the transport of these photoneutrons across the head of various medical accelerators of high energy. The average and most probable neutron energies were obtained from these spectra, before and after crossing the accelerator shielding. The degradation of these spectra, when they cross concrete barriers with thickness which vary between 25 and 100 cm, was also studied.

摘要

光子能量超过10兆电子伏特的医用加速器会在治疗束中产生不需要的快中子污染。在这项工作中，使用蒙特卡罗代码MCNP来模拟这些光中子在各种高能医用加速器头部的传输。在穿过加速器屏蔽前后，从这些能谱中获得了平均中子能量和最可能的中子能量。还研究了这些能谱在穿过厚度在25至100厘米之间变化的混凝土屏障时的退化情况。