电子辐照在核技术应用产业中成为重要的一部分，低能电子束在废水处理、食品保鲜等方面应用越来越广，辐照的计量参数对于辐照质量至关重要。由于低于300keV的电子束剂量学相关标准尚未建立，参数测量都溯源至10MeV电子直线加速器，测量对象的不一致带来了系统性的偏差。本论文针对低于300keV的低能电子，开展了测试与模拟计算相结合的电子束能量测量方法研究，研制了基于量热法的吸收剂量测量装置，探究了吸收剂量与束流强度、位移速度等参数的关系。结果表明：通过阶梯叠层法剂量实验结合能量沉积曲线模拟的方式实现了低能电子能量参数的测量，通过量热法实现了低能电子吸收剂量参数的测量，测量不确定度为11%（k=2）。本研究为低能电子辐照工艺提供了可靠的计量保障。

With the rapid development of the nuclear industry, the amount of waste to be treated and monitored increases, and the potential emissions will also increase, and C-14 needs to be monitored. C-14 produced by nuclear facilities is mainly combined with CO2, so sensitive monitoring of 14CO2 gas is of great significance. In this paper, cavity ring-down spectroscopy (CRDS) is used to detect the CO2 absorption spectrum by selecting the center wave number of 14CO2 absorption line around 2209.11 cm−1. A CO2 detection system based on mid-infrared cavity ring-down spectroscopy is developed by using a quantum cascade laser in mid-infrared band, an optical resonator, and a reasonable optical path design and gas pipeline design. Based on the developed system, different concentrations of CO2 (0.5%-1.3%) were detected, and the experimental data were fitted and analyzed, and the results were found to be consistent with the theoretical formula, which confirmed the feasibility of the developed mid-infrared cavity ring-down spectrum system. The system has successfully realized the accurate measurement of different concentrations of CO2 gas in the mid-infrared band, the absorption spectrum of 14CO2 was measured by mid-infrared cavity ring-down technique, which provides an important technical support and foundation for the future study of laser spectral detection of 14CO2.

Based on traditional alpha radiation detection technology for detecting nearby distances, using the principle of alpha radiation particles inducing air fluorescence, remote measurement of alpha radiation activity can be achieved. By establishing a model for alpha activity measurement based on point sources, and using photomultiplier tubes to measure the photons induced by alpha radiation, an empirical formula relating the source activity to the net photon counting rate of the photomultiplier tube was developed. The study investigated the factors influencing fluorescence conversion efficiency by changing radiation sources of different energies, altering media, and varying pressures. The results showed that the fluorescence conversion efficiency of 241Am source in air to be 3.24×10−6 -7.83×10−6. Sources with higher energy exhibit higher fluorescence conversion efficiency. Pressure shows a linear positive correlation with fluorescence conversion efficiency. Among air, nitrogen, and argon, argon gas was found to effectively enhance the fluorescence efficiency The empirical formula can be used for calculating the activity of radioactive sources. Investigating the factors influencing fluorescence conversion efficiency provides data references for improving the efficiency and accuracy of remote α radiation detection.

During the decommissioning of nuclear facilities and spent fuel reprocessing, conventional alpha particle detectors are insufficient for accurately measuring the emissivity of alpha particles due to their high radiation intensity and complex nuclide types. The air fluorescence method is developed to detect the alpha particle emissivity through measuring the intensity of ultraviolet fluorescence generated by the interaction between alpha particles and nitrogen or other inert gas mediums. This method offers advantages such as long detection range and immunity to gamma radiation interference. The measurement results are primarily influenced by factors including alpha particle energy, detection distance, and gas medium composition, with photon noise and detection distance determining the detection limit. The obtained results indicate that: In the condition of measured in darkness, measurement time for 1000s, and distance for 1 m, The minimum detection limit for alpha sources is 7.6 kBq with a relative standard uncertainty of 10%.

电离室型氚监测仪是监测空气中氚气浓度水平最重要的在线监测设备,为解决国内流气式电离室型氚监测仪的量值传递问题,开展了电离室型氚监测仪校准技术研究.根据质量流量方法建立氚监测仪的实验室校准装置,通过控制充入校准装置标准氚气体积,采用稀释法配制校准用的参考氚气,用于对电离室型氚监测仪进行校准测试;同时在研制的实验室校准装置上开展校准过程影响因素对校准结果影响研究;采用实验室校准装置配制的参考氚气浓度的扩展不确定度为 3.2%～3.6%(k=2);SP1400 氚监测仪对活度浓度为3.10×103～1.98×105 Bq/L范围内氚气响应线性良好(r2 =0.999 3),校准因子为 0.97,标准合成不确定度为 4.3%～5.0%.氚监测仪实验室校准装置可配制不同活度浓度的氚气,对氚监测仪进行校准操作性较好,易于推广,准确度高.

为满足核设施及涉氚场所氚监测仪现场校准需求,开展氚监测仪现场校准技术研究.根据国际标准推荐的校准方法,组建便携式校准装置,采用质量流量法稀释配制校准用的参考氚气,在校准回路中引入参考电离室,对现场氚监测仪进行校准测试.结果表明,在便携式校准装置上,可配制不同活度浓度的参考氚气,用于不同量程的氚监测仪校准.经校准,M347氚监测仪校准因子为1.09,合成标准不确定度为5.6％(k=2).用于现场校准的便携式校准装置可利用浓度已知的氚标准源配制三个不同量级活度浓度的氚气,对氚监测仪进行校准可操作性较好、易于推广、准确度高.

In order to solve the problem which is quantity traceability of ionization chamber tritium monitor,the calibration method of ionization chamber tritium monitor was studied.The laboratory calibration device of the tritium monitor was established.Tritium gas standard source and ionization chamber tritium monitor are used as research objects,the influencing factors in the calibration process are studied,including the gas pressure and humidity in the calibration circuit,the retention effect of tritium in the calibration circuit and the surrounding environment γ Radiation,etc.Finally,the appropriate calibration conditions are determined.The calibration tritium gas with different activity concentrations is obtained by controlling the volume of tritium gas standard source filled into the calibration device,and the response of tritium monitor to tritium activity concentration is measured.The ionization chamber tritium monitor has a good linear response to tritium gas activity（R~2=0.999 4）,the calibration factor is 1.17,and the expanded uncertainty（k=2） is 8.0%

氚是涉氚场所中辐射防护监测的重点核素,对涉氚场所中的气态氚浓度进行有效监测具有重要的意义.根据GB/T 7165.5-2008第5部分要求,氚活度监测校准应使用与被测对象成分一致的参考源,即标准氚气.解决该难题需要研究并建立标准氚气的制备方法和定值方法,确保氚气活度量值源头的有效性.基于稀释法研制了气载氚标准源,通过长度补偿法进行氚活度浓度定值,并进行了不确定度的分析和评定.氚气标准源的研制填补了国内该领域的空白,为氚监测仪的量值溯源提供了重要支撑.