Propagation of gamma rays and production of free electrons in air
Propagation of gamma rays and production of free electrons in air
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伽马射线在空气中的传播和自由电子的产生
DOI：
10.1063/1.4762007
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
V. Granatstein
中科院分区：
文献类型：
--
作者：
Y. Dimant;G. Nusinovich;P. Sprangle;J. Peñano;C. Romero;V. Granatstein
最近提出了一种远程探测隐藏放射性物质的新概念\cite{Gr.Nusin.2010} - \cite{NusinSprangle}。它是基于太赫兹回旋管产生的高功率电磁波束的焦点在空气中的击穿。为了引发雪崩击穿，在电磁脉冲期间，种子自由电子应该存在于这个焦点区域。本文对放射性物质泄漏的伽马射线产生自由电子进行了分析。在离辐射源100米范围内，自由电子的波动速率可能大大超过自然本底电离速率。在大约10微秒长度的回旋加速器脉冲期间，这些电子可能为电击穿埋下种子，并在焦点区域产生足够密集的等离子体，从而作为隐藏的放射性物质的明确效应被检测到。
A new concept of remote detection of concealed radioactive materials has been recently proposed \cite{Gr.Nusin.2010}-\cite{NusinSprangle}. It is based on the breakdown in air at the focal point of a high-power beam of electromagnetic waves produced by a THz gyrotron. To initiate the avalanche breakdown, seed free electrons should be present in this focal region during the electromagnetic pulse. This paper is devoted to the analysis of production of free electrons by gamma rays leaking from radioactive materials. Within a hundred meters from the radiation source, the fluctuating free electrons appear with the rate that may exceed significantly the natural background ionization rate. During the gyrotron pulse of about 10 microsecond length, such electrons may seed the electric breakdown and create sufficiently dense plasma at the focal region to be detected as an unambiguous effect of the concealed radioactive material.