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放射性纳米气溶胶特性行为及过滤研究一直是辐射防护关注的内容,但目前缺乏单分散纳米气溶胶发生器和高灵敏的气溶胶在线检测器。为模拟示踪放射性气溶胶纳米粒子,并适合用质谱仪进行在线检测分析,本文采用蒸发-冷凝原理研制出一种纳米气溶胶发生器,能够利用含低熔点物质(如氯化钠和硝酸银)的溶液,输出准单分散、较高数浓度的纳米气溶胶。用标定后的扫描迁移率粒子谱仪对发生器进行性能测试,结果表明:输出纳米气溶胶的粒度分布符合对数正态分布,在建议工况下,输出粒子的峰位粒径约30 nm,几何标准偏差约1.3,数浓度达106cm-3,数浓度波动小于10%。发生器成本低、性能可靠、使用灵活,能够满足放射性气溶胶特性模拟和过滤净化技术研究等需求。
Radioactive nano-aerosol characteristic behavior and filtration studies have been the focus of radiation protection, but the current lack of monodisperse nano-aerosol generator and highly sensitive on-line aerosol detector. In order to simulate the tracer of radioactive aerosol nanoparticles, and suitable for on-line detection and analysis by mass spectrometer, a nano-aerosol generator was developed by using evaporative-condensation principle, which can make use of materials containing low melting point substances such as sodium chloride and silver nitrate ) Solution, the output quasi-monodisperse, a higher concentration of nano-aerosol. The performance of the generator was tested with a calibrated scanning mobility particle spectrometer. The results show that the particle size distribution of the output nano-aerosol is lognormal distribution. Under the proposed operating conditions, the particle size of the output particle is about 30 nm , The geometric standard deviation of about 1.3, the number of concentrations of 106cm-3, the number of concentration fluctuations of less than 10%. Low generator cost, reliable performance, flexible use, to meet the needs of radioactive aerosol simulation and purification technology research and other needs.