量子化霍尔电阻国家标准的研究  

A Study on the National Standard of Quantum Hall Resistance

作　　者：张钟华[1] 贺青[1] 李正坤[1] 刘勇[1] 

机构地区：[1]中国计量科学研究院,北京100013

出　　处：《计量学报》2005年第2期97-101,共5页Acta Metrologica Sinica

基　　金：国家自然科学基金(60076031);国家科技部基金(2001DEA20013)

摘　　要：中国计量科学研究院在2003年建成了量子化霍尔电阻标准装置。成功研制了系统的核心器件—量子化霍尔器件。并通过对低温电流比较仪系统及运行过程的研究,发现了氦气气压波动引起的冻结磁通蠕动导致的附加噪声是限制系统不确定度的主要原因。进而提出了一种新型的气压滤波器,消除了这些干扰因素。还改进了电路动态特性,改善了前馈补偿环节,把匝数比提高了8倍,信噪比也因而提高了8倍。完成的量子化霍尔电阻标准装置的综合不确定度为2.4×10-10(k=1)。A Quantum Hall Resistance (QHR) standard was established at NIM in 2003. The QHR samples used are designed and fabricated successfully. A Cryogenic Current Comparator (CCC) is developed to disseminate the QHR value to the decimal resistances. It is found that the main source of uncertainty in the system is the additional noise from the movement of the frozen flux by the pressure fluctuation in the cryostat, which disturbs the system during the dynamic process. Thus a new type of helium gas filter is designed to solve this problem. In addition, a series of measures are taken to improve the dynamic characteristic and feed-forward unit. Then a ratio with higher turn numbers about 8 times more than the former is attend and the S/N is improved correspondingly too. The total uncertainty of the QHR standard established at NIM is only several parts in 10^(-10)(k=1).

关 键 词：计量学 电阻标准 量子化霍尔电阻 低温电流比较仪 信噪比 不确定度 

分 类 号：TB971[一般工业技术—计量学]