基于双LED光源积分球的硅探测器宽动态范围响应线性定标

Linear Calibration of Wide Dynamic Range Response of Silicon Detectors Based on Double LEDs Light Source Integrating Sphere

介绍了一种硅探测器宽动态范围线性测量系统,系统以光通量叠加为基础,通过时间逻辑控制LED点亮、熄灭和采集数据,在2.2×10-6~0.57A的LED注入电流调节范围内,标定了硅探测器响应电流在3.92×10-11~10-2 A范围内近9个量级的线性。实验结果表明,硅探测器在9个量级的动态范围内测量时探测器非线性引入的误差可达0.23%,通过非线性修正因子对其测量值进行修正很有必要,并给出了非线性修正因子,其数值范围为1~1.0023。分析了测量结果的测量不确定度,列出影响系统测量精度的因素,并定量分析了LED光源的光谱漂移对系统测量精度的影响。给出了线性测量系统的相对合成不确定度,硅探测器响应电流范围分别为39.2pA^0.326nA、0.326~81.6nA、81.6nA^20.4μA、20.4μA^10.2 mA时的测量不确定度分别为0.269%、0.0116%、0.00536%和0.00320%。结果表明该系统可以用于高精度硅探测器的宽动态范围响应线性定标。

A wide dynamic range linear measurement system of silicon detector is introduced. The system is based on flux addition, which controls the LEDs to turn on, off and the collector to collect data through time logic. In the adjustment range of LED injection current of 2.2×10^-6-0.57 A, nearly nine orders linearity of silicon detector response current within the range of 3.92×10^-11-10^-2 A is calibrated. The experimental results show that the error introduced by the nonlinearity of the detector can reach 0.23% when the silicon detector is measuring in the dynamic range of nine orders and it is necessary to correct the measured value by the nonlinearity correction factor. In the end, a nonlinearity correction factor is given, ranging from 1 to 1.0023. The measurement uncertainty of the measurement results is analyzed, and the factors that affect the measurement accuracy of the system are listed. The influence of the spectral drift of the LED light source on the measurement accuracy of the system is analyzed quantitatively. The measurement uncertainties are 0.269%, 0.0116%, 0.00536% and 0.00320%, when the response current ranges of the silicon detector are 39.2 pA-0.326 nA, 0.326-81.6 nA, 81.6 nA-20.4 μA and 20.4 μA-10.2 mA respectively. The result shows that the system can be used in wide dynamic range response of high accuracy silicon detectors.