一种新型低温固定点器件——~4Heλ转变密封瓶  

A NEW LOW TEMPERATURE FIXED POINT DEVICE: SEALED ~4He LAMBDA TRANSITION CELL

作　　者：林鹏[1] 毛玉柱[1] 洪朝生[1] 

机构地区：[1]中国科学院低温技术实验中心,北京100080

出　　处：《低温物理学报》2000年第2期149-155,共7页Low Temperature Physical Letters

基　　金：国家自然科学基金资助项目

摘　　要：本文介绍一种高复现性的新型低温固定点器件带毛细管结构的4 Heλ转变密封瓶的制作和使用方法 .使用一般的绝热恒温器 ,只需简单控制平台和密封瓶下池的温度 ,即可方便地观测到不平度小于 0 .0 5mK长达数小时的4 Heλ转变温坪 .实验数据表明 ,通过毛细管的热流对λ转变温度测量值有一定的下压作用 ,其数值为 10 0 μW下压量为 0 .38mK .改变通过毛细管的热流 ,测出多个不同热流下的温坪值 ,外推到零热流 ,就可得到真实的Tλ 温度(2 .176 8K) .The presents a method to realize the\ \+4He lambda transition temperature using a sealed cell with a special capillary tail containing the HeI/HeII interface within it. Because of the self adjusting effect for the height of HeI column within the capillary, the temperature fluctuation on a typical lambda transition plateau is less than 0.05mK. The transition plateau, as measured at the HeII cell, is affected by the heat flux flowing along the helium column within the capillary and the depression by heat flux is 3.8μK/μW in our case. By extrapolating to zero heat flux, the lambda transition temperature has been determined with a reproducibility of 0.08mK.

关 键 词：低温固定点器件 液氦 λ转变 密封瓶 

分 类 号：O513[理学—低温物理]