Resonant frequency change of torsional oscillator induced by solid4He in torsion rod

Yuki Aoki, Izumi Iwasa, Takeru Miura, Daisuke Takahashi, Akira Yamaguchi, Satoshi Murakawa, Yuichi Okuda

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The contribution of solid 4He contained in the torsion rod of a torsional oscillator to its resonant frequency is investigated using a modified torsional oscillator. The purpose of the present study is to discriminate between two possible contributions to the resonant frequency of the torsional oscillator, which abruptly increases below ∼0.2 K. The first possible contribution is the elastic property change of solid 4He in the torsion rod (i.e., shear modulus increase), and the second possible contribution is mass decoupling by the supersolid transition of solid 4He in the oscillating body (i.e., a decrease in the momentum inertia). A torsional oscillator that has no hollow space for solid 4He in the body was constructed, and its resonant frequency and Q-factor were compared to those of the conventional oscillator. The shear modulus contributions of solid 4He in the torsion rod were identical, but the momentum inertias of solid 4He in the oscillating body were quite different between the two oscillators. Surprisingly, the observed frequency behavior and magnitude of the two oscillators were comparable. This finding indicates that the resonant frequency increase observed in the torsional oscillator originates from the increase in the shear modulus of solid 4He in the torsion rod, rather than from the momentum inertia decrease of the solid 4He in the oscillating body. The temperature dependence of the increase in the shear modulus of solid 4He was well reproduced by the dislocation-vibration model with a much lower 3He impurity concentration than that of commercially available 4He gas.

Original languageEnglish
Article number084604
JournalJournal of the Physical Society of Japan
Volume83
Issue number8
DOIs
Publication statusPublished - 2014 Aug 15

Fingerprint

torsion
resonant frequencies
rods
oscillators
inertia
shear
momentum
decoupling
Q factors
hollow
elastic properties
impurities
vibration
temperature dependence
gases

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Aoki, Y., Iwasa, I., Miura, T., Takahashi, D., Yamaguchi, A., Murakawa, S., & Okuda, Y. (2014). Resonant frequency change of torsional oscillator induced by solid4He in torsion rod. Journal of the Physical Society of Japan, 83(8), [084604]. https://doi.org/10.7566/JPSJ.83.084604

Resonant frequency change of torsional oscillator induced by solid4He in torsion rod. / Aoki, Yuki; Iwasa, Izumi; Miura, Takeru; Takahashi, Daisuke; Yamaguchi, Akira; Murakawa, Satoshi; Okuda, Yuichi.

In: Journal of the Physical Society of Japan, Vol. 83, No. 8, 084604, 15.08.2014.

Research output: Contribution to journalArticle

Aoki, Y, Iwasa, I, Miura, T, Takahashi, D, Yamaguchi, A, Murakawa, S & Okuda, Y 2014, 'Resonant frequency change of torsional oscillator induced by solid4He in torsion rod', Journal of the Physical Society of Japan, vol. 83, no. 8, 084604. https://doi.org/10.7566/JPSJ.83.084604
Aoki, Yuki ; Iwasa, Izumi ; Miura, Takeru ; Takahashi, Daisuke ; Yamaguchi, Akira ; Murakawa, Satoshi ; Okuda, Yuichi. / Resonant frequency change of torsional oscillator induced by solid4He in torsion rod. In: Journal of the Physical Society of Japan. 2014 ; Vol. 83, No. 8.
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