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Frequency-dependent drag from quantum turbulence produced by quartz tuning forks in superfluid He4

Research output: Contribution to journalJournal article

Published

Article number014515
Journal publication date30/01/2014
JournalPhysical Review B
Journal number1
Volume89
Number of pages10
Original languageEnglish

Abstract

We have measured the drag force from quantum turbulence on a series of quartz tuning forks in superfluid helium. The tuning forks were custom made from a 75-μm-thick wafer. They have identical prong widths and prong spacings, but different lengths to give different resonant frequencies. We have used both the fundamental and overtone flexure modes to probe the turbulent drag over a broad range of frequencies f=ω/2π from 6.5 to 300 kHz. Optical measurements show that the velocity profiles of the flexure modes are well described by a cantilever beam model. The critical velocity for the onset of quantum turbulence at low temperatures is measured to be vc≈0.7κω−−−−−√ where κ is the circulation quantum. The drag from quantum turbulence shows a small frequency dependence when plotted against the scaled velocity v/vc

Bibliographic note

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.