The process that the alpha particles emitted by the nuclear pollutants react with the nitrogen molecules in the air will produce ultraviolet photons with wavelengths of 280-390 nm, which can be detected by a photomultiplier tube. In this paper, a set of nuclear pollutant detection system based on photon counting detection system is designed. Firstly, the principle and development of nuclear pollution detectors and the development status of single photon detection technology are introduced. Then the overall system structure is introduced, the system is mainly composed of mechanical baffle, filter, photomultiplier, photon counter and upper computer software. The photon counter is composed of the preamplifier module, the signal discriminating circuit module and the pulse counting module. Finally, the detection experiment of the nuclear standard source is carried out, and the experimental results are analyzed. The analysis results show that the system can be used for the detection of nuclear pollutants in alpha particle sources.
Microchannel plates (MCP) are devices that achieve electronic multiplication in the low-light intensifier system. MCP have the advantages of high gain, small size and light weight, being widely used in modern low-light, infrared, and ultraviolet image detection fields. In this paper, the fatigue and damage of MCP caused by strong input current are studied. The fatigue and damage of MCP are mainly reflected by the change of gain and body resistance. Experiments show that the gain of the MCP decreases under the condition of strong electron flow (2nA), and the body resistance decreases sharply after being damaged.
With the development of the state grid, there is a great demand for equipments to detect the corona discharge on high-voltage transmission lines. The uncooled infrared image and solar-blind UV image fusion camera is supposed to achieve the purpose. Image fusion is an important method to integrate the features from images of different band spectrum into a single frame for enhanced visual perception. The image fusion camera consists of infrared channel, solar-blind UV channel, imaging processing module and display module. An image fusion rule based on the Laplacian pyramid decomposition is proposed. The fusion methodology is divided into several steps: image preprocessing, Gaussian pyramid decomposition, Laplacian pyramid decomposition, image fusion and reconstruction. The algorithm is implemented on the image fusion camera. The camera is verified to detect the corona discharge for fault diagnosis of high-voltage power system. Keywords: uncooled infrared FPA, image fusion, solar-blind UV, corona discharge