弗兰克-赫兹实验条件的优化方法及定量评估  

Optimizing method and quantitatively evaluation on experimental conditions for Frank-Hertz experiment

作　　者：李潮锐 LI Chao-rui(School of Physics,Sun Yat-sen University,Guangzhou,Guangdong 510275,China)

机构地区：[1]中山大学物理学院,广东广州510275

出　　处：《大学物理》2023年第7期28-31,52,共5页College Physics

基　　金：国家自然科学基金(61975244);中山大学2022年度教学质量与教学改革工程项目(教务[2022]91号)资助。

摘　　要：弗兰克-赫兹实验的物理内容丰富,虽然过去已从不同角度对实验条件优化问题进行了广泛讨论.本文系统地分析了实验优化方法及其评估依据,有助于深刻理解实验物理.本文利用实验装置所附的默认参数,得到初步实验结果.根据集电极电流的测量原理,选定集电极电位接近但小于激发电位实验值,进而根据灯丝温度对热电子发射密度的影响规律,调节合适灯丝电压(电流).最后,改变并观察第一栅极电位影响,由峰处和谷处集电极电流均值及其标准偏差为指标,定量评估实验优化水平,寻找最佳实验条件,以期可得到更合理的实验结果.Frank-Hertz experiment has substantial physics content,and the optimization of its experimental conditions has been extensively discussed in the past.It is a right choice to clearly understand experimental physics by introducing experimental optimizing method and its physical judgment.The preliminary experimental results are obtained by using default parameters provided by equipment manufacturer.On the basis of measurement principles,the collector potential is set to be close to but less than the experimental excitation potential.Then,the filament voltage(current)is appropriately adjusted according to the influence of filament temperature on hot electron emission density.Finally,the first grid potential is changed and its influence is observed.The experimental optimization level is quantitatively evaluated with an indicator defined as the mean and standard deviation of collector current values at the peak and the valley.The accurate experimental results can be obtained on the optimal experiment condition.

关 键 词：弗兰克-赫兹实验 激发电位 最佳实验条件 评估依据 

分 类 号：O4-34[理学—物理]