TY - JOUR
T1 - A Simple Experimental Setup for Simultaneous Superfluid-Response and Heat-Capacity Measurements for Helium in Confined Geometries
AU - Usami, Jun
AU - Toda, Ryo
AU - Nakamura, Sachiko
AU - Matsui, Tomohiro
AU - Fukuyama, Hiroshi
N1 - Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2022/9
Y1 - 2022/9
N2 - Torsional oscillator (TO) is an experimental technique which is widely used to investigate superfluid responses in helium systems confined in porous materials or adsorbed on substrates. In these systems, heat capacity (HC) is also an important quantity to study the local thermodynamic properties. We have developed a simple method to incorporate the capability of HC measurement into an existing TO without modifying the TO itself. By inserting a rigid thermal isolation support made of alumina and a weak thermal link made of fine copper wires between a standard TO and the mixing chamber of a dilution refrigerator in parallel, we were able to carry out simultaneous TO and HC measurements on exactly the same helium sample, i.e., four atomic layers of 4He adsorbed on graphite, with good accuracies down to 30 mK. The data reproduced very well the previous workers’ results obtained independently using setups optimized for individual measurements. This method is conveniently applicable to a variety of experiments where careful comparisons between results of TO and HC measurements are crucial. We describe how to design the thermal isolation support and the weak thermal link to manage conflicting requirements in the two techniques.
AB - Torsional oscillator (TO) is an experimental technique which is widely used to investigate superfluid responses in helium systems confined in porous materials or adsorbed on substrates. In these systems, heat capacity (HC) is also an important quantity to study the local thermodynamic properties. We have developed a simple method to incorporate the capability of HC measurement into an existing TO without modifying the TO itself. By inserting a rigid thermal isolation support made of alumina and a weak thermal link made of fine copper wires between a standard TO and the mixing chamber of a dilution refrigerator in parallel, we were able to carry out simultaneous TO and HC measurements on exactly the same helium sample, i.e., four atomic layers of 4He adsorbed on graphite, with good accuracies down to 30 mK. The data reproduced very well the previous workers’ results obtained independently using setups optimized for individual measurements. This method is conveniently applicable to a variety of experiments where careful comparisons between results of TO and HC measurements are crucial. We describe how to design the thermal isolation support and the weak thermal link to manage conflicting requirements in the two techniques.
KW - Heat capacity
KW - Helium in confined geometries
KW - Phase transition
KW - Superfluid
KW - Torsional oscillator
KW - Two-dimensional
KW - Two-dimensional helium
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U2 - 10.1007/s10909-021-02658-9
DO - 10.1007/s10909-021-02658-9
M3 - Article
AN - SCOPUS:85123834174
SN - 0022-2291
VL - 208
SP - 457
EP - 466
JO - Journal of Low Temperature Physics
JF - Journal of Low Temperature Physics
IS - 5-6
ER -