CCD相机对14MeV和2.5MeV中子瞬态响应特性

从理论上分析了中子在CCD相机拍摄图像中引起的瞬态干扰噪声的机理,并针对两种不同类型的CCD相机,在能量为14MeV和2.5MeV的低强度稳态中子源上开展了实验研究,分析了噪声特征与入射中子能量、入射角度、注量及CCD相机结构的关系。实验结果表明中子瞬态干扰噪声主要表现为脉冲噪声,且出现斑点现象,与理论分析结果相吻合。研究得出了噪声特征随入射中子注量变化的规律,比较了不同能量及不同入射角条件下的噪声特性,并分析了两种不同结构的CCD相机响应特性的差别。

Transient response of CCD cameras to 14 MeV and 2.5 MeV neutrons

The mechanism of transient noise of CCD cameras induced by neutrons was analyzed. On the neutron beams of 14 MeV and 2.5 MeV, the transient noise of two different CCD cameras was measured at different fluences and different incidence angles. The preliminary results were drawn from the experiment. Transient noise induced by neutron usually appears as sharp spikes or impulses affecting one or a small cluster of pixels. The results are consistent with theoretical estimates. We also obtained the variation characteristics of transient noise induced by neutrons of different fluences, or different energies, or different incidence angles. In addition, we investigated the transient noise as a function of the size of CCD pixel.