JAEA：核材料无损检测：低成本可疑物体检测
-开发低成本、高便携性的核材料探测器-
JAEA：
机场等交通相关设施需要检测隐藏在行李中的核材料。
核材料探测器价格昂贵：
用放射线照射物体进行检查的有源装置性能最高。
但是，有源器件存在价格昂贵、体积大的问题。
有源设备昂贵的原因是它需要结合辐射发生器。
辐射发生器的成本降低：
如果能降低辐射发生器的成本，就可以降低有源器件本身的成本。
所以，
高速旋转辐射源，
改变辐射强度，
我们开发了放射线发生器（旋转照射装置）。
价格低廉的旋转辐照装置：
开发了一种比传统有源装置更便宜和更小的旋转辐照装置。
此外，我们还制作了一个包含此功能的有源器件原理演示器。
确认的核材料检测性能：
我们通过实验证实，它具有与传统有源器件相同的检测性能。
使用领域：
从现在开始，
不仅是交通相关设施的检查等。
预计它还将用于大型活动中的可疑物体检查。
日本原子能厅：新闻稿
https://www.jaea.go.jp/02/press2021/p21060402/
A reliable and robust non-destructive detection method for nuclear materials using a neutron source
2021.06.07
With the increase of today’s global terrorist threat,
a large-scale terrorist attack using nuclear materials
that can cause enormous damages can actually occur.
Consequently,
devices for nuclear security that are used to detect nuclear materials
have grown increasingly important.
The detection method called the active neutron method is the most potential candidate for it.
In the active neutron method,
neutrons are irradiated into a container containing nuclear materials and then measures the emitted fission neutrons.
Though a conventional active method using a D-T tube
has high performance to detect small nuclear materials, it has significant drawbacks of being massive and quite expensive.
We therefore developed a new active neutron method that does not use a D-T tube.
The new method that we call rotation method
is a novel method for detecting nuclear materials using a neutron source such as californium.
In this method,
while a neutron source is rotated rapidly nearby a measurement object, neutron measurement is carried out by synchronizing the rotation motion.
If the object contains a nuclear material, as the rotation speed increases,
the larger deformation of time distribution of neutron counts is observed, which in turn resulted to the detection of the nuclear material.
In addition to its features of low cost and portability,
this method is capable of detecting uranium that emits very few spontaneous fission neutrons.
We presented the fundamental principle of this method and its effectiveness for detecting nuclear materials through the experimental verifications.
The results of this study have been published in the Annals of Nuclear Energy entitled as “First demonstration experiment of the neutron rotation method for detecting nuclear material”.
JAEA HP Press release (Japanese only)
Press Release – JAEA Nuclear Science and Engineering Center