【作者】 边海琴；

【导师】 孙爱民；

【作者基本信息】 西北师范大学 ， 凝聚态物理， 2005， 硕士

【摘要】 本论文首先简要综述了低温技术的发展概况,对获得低温及极低温的主要方法进行了简单的介绍,同时简要评述了低温技术的应用。接着论文主要计算分析了低温测量中热沉的尺寸效应。 利用热沉是为了减小引线导热在温度计上的热负荷,提高温度测量的精确度,所以利用热沉是经常而必用的手段。论文分析了一维、二维热沉的尺寸效应,并且讨论了大电流测量中的一维热沉设计。 论文首先对一维热沉进行了理论分析和计算,获得引线长度越长,所需热沉的长度就越短,而且有效减小了温度计上的热负荷,保证了温度的精确测量。本论文还计算分析了二维椭圆形热沉的尺寸效应,计算结果与分析表明利用二维热沉比一维热沉更可取,在热沉使用中对漏热与尺寸问题进行了比较仔细的讨论。在大电流测量的实验中,计算分析了一维热沉的设计,并讨论了一维热沉长度与电流和引线长度之间的关系,同时指出在设计热沉时必须考虑引线自热(即电流的热效应)和热沉自热。连接热沉段与温度传感器之间的引线要尽量选择的短而粗,这样可以有效的减小由于引线自热传导至温度计上的热负荷。本论文所得出的结论可作为设计实验装置选取热沉尺寸的参考依据。 计算结果与分析表明,在低温物理实验测量中,采用热沉是非常有效而且是必要的,特别是利用二维热沉比一维热沉更可取。热沉能够保证有效地减小温度计上的热负荷,提高温度测量的精确度。更多还原

【Abstract】 First, the development of the low-temperature technology is reviewed in the paper, the most means is simply introduced to obtain the low temperature and infinitesimal temperature, and the application of low-temperature technology is introduced. In succession, the paper calculated and analyzed size effect of heat sink in the low-temperature measurement.To reduce the amount of heat load in the thermometer due to electrical leads of heat conduction and improve the accuracy of temperature measurement, it is very important and virtual to utilize heat sink. The paper analyzed and discussed one-dimensional and two-dimensional heat sink in theory.The result of calculation in one-dimensional heat sink shows that the length of heat sink is reduced with increasing electrical leads. In this way, heat load of thermometer is reduced, so as to guarantee the precision of temperature measurement. In this paper, we analyzed and discussed size effect of two-dimensional heat sink in theory. The result of calculation and analysis indicates that two-dimensional heat sink is better than one-dimensional one. Various kinds of leak heat and size of heat sink are particularly discussed in the use of heat sink. Device of one-dimensional heat sink is calculated and analyzed in big electric current and low-temperature, and the relationship been discussed among the length of one-dimensional heat sink, electric current and the length of electrical leads, self-heating of the electrical leads and the heat sink must be calculated in the device of heat sink, it is much shorter and thicker, it is much better that electrical leads connect temperature sensor and heat sink, so as to reduce the heat load on the thermometer.The result of calculation and analysis indicates that in the low-temperature experimental measurement, it is necessary and effective to use heat sink, especially in two-dimensional heat sink. The heat sink can effectively guarantee the reducing of the heat load on the thermometer, and improve the accuracy of temperature measurement.更多还原