Determination of the detection limit and decision threshold for continuously radioactive iodine monitoring;
放射性碘连续监测系统判断阈和探测限的确定
Two test methods, natural radioactive background method and decay method, used to verify the detection limit of radioactive aerosol monitors are studied.
两种方法不仅可检测监测仪的探测限 ,而且对各种监测仪探测限指标的物理意义能给以正确判断。
Results are that the absolute value of ～10 -10 g has been measured for elements of Ti and Cu in thin sample, the detection limit is about 1-10ppm order of magnitude for Cr in the substance of light base, and a well proportional relation exists between the counts of net integrated area and the concentration of Cr in the samples of homogenized solut.
其结果是 :对含Ti和Cu的薄样品 ,绝对检测量可达 10 - 10 g级 ;对轻基体样品 ,Cr的探测限可达 1— 10ppm ;并且在含Cr的均匀液体样品中Cr峰面积积分净计数与其含量有良好的正比关系 。
At passive assay mode, the detection limit is about 1 mg 240 Pu eff .
无源工作方式下的探测下限为 1mg2 40 Pueff。
So,we put forward a device for promoting the low-light level imaging system detection limit in which a magnetic mirror structure is coupled between the photocathode and the photoelectron acceptor(screen target),viz.
阐述了提高微光成像系统低照度探测极限的本质是需保证成像系统对光信号足够的积累时间,从理论上指出降低CCD温度实现低照度探测的局限性和实现技术的复杂性后,提出在光阴极与光电子接收器(屏靶)之间耦合一个磁镜装置(即微通道电子瓶板结构)作为一种新的光电子接收器,即可有效保证图像信号的积分时间,提高成像系统的探测信噪比,达到拓展微光成像系统低照度探测极限的目的。