School of Nuclear Science & Engineering, North China Electric Power University, Beijing, China.
Br J Radiol. 2012 Oct;85(1018):e925-32. doi: 10.1259/bjr/68583711. Epub 2012 May 9.
To simulate the neutron-based sterilisation of anthrax contamination by Monte Carlo N-particle (MCNP) 4C code.
Neutrons are elementary particles that have no charge. They are 20 times more effective than electrons or γ-rays in killing anthrax spores on surfaces and inside closed containers. Neutrons emitted from a (252)Cf neutron source are in the 100 keV to 2 MeV energy range. A 2.5 MeV D-D neutron generator can create neutrons at up to 10(13) n s(-1) with current technology. All these enable an effective and low-cost method of killing anthrax spores.
There is no effect on neutron energy deposition on the anthrax sample when using a reflector that is thicker than its saturation thickness. Among all three reflecting materials tested in the MCNP simulation, paraffin is the best because it has the thinnest saturation thickness and is easy to machine. The MCNP radiation dose and fluence simulation calculation also showed that the MCNP-simulated neutron fluence that is needed to kill the anthrax spores agrees with previous analytical estimations very well.
The MCNP simulation indicates that a 10 min neutron irradiation from a 0.5 g (252)Cf neutron source or a 1 min neutron irradiation from a 2.5 MeV D-D neutron generator may kill all anthrax spores in a sample. This is a promising result because a 2.5 MeV D-D neutron generator output >10(13) n s(-1) should be attainable in the near future. This indicates that we could use a D-D neutron generator to sterilise anthrax contamination within several seconds.
使用蒙特卡罗 N 粒子（MCNP）4C 代码模拟基于中子的炭疽污染灭菌。
中子是基本粒子，不带电荷。与电子或γ射线相比，它们在杀死表面和封闭容器内的炭疽孢子方面有效 20 倍。从（252）Cf 中子源发射的中子能量范围为 100keV 至 2MeV。目前技术条件下，2.5MeV 的 D-D 中子发生器可以产生高达 10（13）n s（-1）的中子。所有这些都使杀死炭疽孢子成为一种有效且低成本的方法。
在使用反射器的情况下，当反射器的厚度超过其饱和厚度时，对炭疽样品的中子能量沉积没有影响。在 MCNP 模拟中测试的所有三种反射材料中，石蜡是最好的，因为它的饱和厚度最薄，并且易于加工。MCNP 辐射剂量和通量模拟计算还表明，模拟杀死炭疽孢子所需的 MCNP 模拟中子通量与之前的分析估算非常吻合。
MCNP 模拟表明，来自 0.5g（252）Cf 中子源的 10 分钟中子辐照或来自 2.5MeV D-D 中子发生器的 1 分钟中子辐照可能杀死样品中的所有炭疽孢子。这是一个很有前途的结果，因为在不久的将来应该可以获得输出>10（13）n s（-1）的 2.5MeV D-D 中子发生器。这表明我们可以在几秒钟内使用 D-D 中子发生器来对炭疽污染进行灭菌。
