基于纳米改性液闪能谱技术的湿法放射性气溶胶测量及其能量分辨增强机制研究

The high-precision and high-stability monitoring of radioactive aerosols is an important requirement safety technology for the new generation of nuclear submarines. This project combines the high efficiency/homogeneity collection of the mist-spray process with the high detection efficiency of liquid scintillation radioactivity measurement, a new wet-process radioactive aerosol measurement technology with high resolution for special purposes such as radioactive monitoring in nuclear submarine cabins is proposed. In order to promote the aerosols collection efficiency, improve the luminescent properties of nano-modified liquids, and optimize the accuracy of energy spectrum analysis algorithms, some research should be focused on. The research contents include: 1) Revealing physical mechanism of high-efficiency wet aerosol collection based on the properties of the two-phase interface; 2) Quantum dot/nano-metal particle modified liquid scintillator make a breakthrough improvement of detection accuracy and energy resolution; 3) New system liquid scintillator performance degradation mechanism and environmental applicability assessment; 4) The algorithm developed here is based on deconvolution and deep learning, with the aim of analyzing nuclear signal and energy spectrum measured under low noise and energy circumstance. This project is a cross-disciplinary research project integrating radiation detection, environmental engineering, nanomaterials, signal processing and electronics. The research results achieved will provide advanced theory and technological foundation for the development of accurate and intelligent radioactive aerosol monitoring instruments in China’s new generation of nuclear submarines.

放射性气溶胶的高精度、高稳定监测是新一代核潜艇安全技术的重要需求。本项目结合湿法喷淋采集的高效/均一性与液闪放射性测量的高探测效率，提出了一种面向核潜艇舱内放射性监测等特殊用途的新型高分辨率湿法放射性气溶胶测量技术，并针对其湿法气溶胶采集效率提升、纳米改性液闪发光性能改善、能谱解析算法精度优化等关键技术开展重点研究。研究内容包含：1）基于两相界面性质揭示湿法气溶胶采集高效率的物理机制；2）量子点/纳米金属颗粒改性液体闪烁体对探测精确度与能量分辨率的提升突破；3）新体系液体闪烁体性能退化机制与环境适用性评估；4）去卷积联合深度学习算法实现低噪声、低能耗下的核信号处理与能谱解析。本项目是集辐射探测、环境工程、纳米材料、信号处理与电子学等多学科内容交叉的研究课题，其研究成果将为研发我国新一代核潜艇舱内精确、智能的放射性气溶胶监测装置奠定良好的理论与技术基础。

针对气溶胶湿法采集液闪探测技术开展了湿法气溶胶采集技术、液闪数字化技术与荧光增强技术的研究，重点针对气溶胶采集系统与液闪测量系统进行了设计与开发。主要研究成果有：1）建立了湿法放射性气溶胶采集系统的结构模型，精确模拟了气溶胶微粒在采集系统的输运过程，构建了各项参量与采集性能的响应关系，在调整入射参数与加入双喷雾系统后，收集效率达到86%；2）制备测试了两种碘离子富集材料，研究发现只需几克20%- Ag2O-Ag2O3@ZIF-8材料，即可完成对捕获液中碘离子的快速去除；3）制备了掺杂CdSe/ZnS量子点的新型液体闪烁体，研究发现新型液闪的荧光强度与溶剂种类有较大的关系，Ultima Gold液闪在加入量子点后整体发光强度有了轻微提升，Emulsifier-Safe液体闪烁体掺杂量子点后大部分蓝紫荧光被转移，但发光强度有了轻微下降，使用时需要结合光电转换效率综合考虑；4）项目搭建了液闪探测平台系统，制备了基于FPGA的双通道数字化谱仪，实现了粒子甄别功能，开发了GAN网络解谱算法，研究了系统在多核素存在条件下的解谱性能；5）在质子辐照闪烁体后，发光强度有了一定下降，随着辐照射线能量的增大，下降幅度也逐渐增大；6）发表SCI学术论文4篇；中文核心期刊论文2篇；申请国家发明专利2项；获得江苏省微课教学比赛二等奖；培养研究生4名，博士生2名。