Time-of-flight measurements of vortices emitted from quantum turbulence in superfluid 4He

H. Kubo, Yusuke Nago, A. Nishijima, K. Obara, H. Yano, O. Ishikawa, T. Hata

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

An oscillating obstacle generates quantum turbulence in superfluids, when vortices remained attached to obstacle surfaces or vortex rings collided with it during oscillation. Turbulence provides a source of vortices; however, the characteristics of these vortices are not clear. In the present work, we report the flight of vortices emitted from quantum turbulence in superfluid 4He at low temperatures, using vibrating wires as a generator and a detector of vortices. A vortex-free vibrating wire can detect only the first colliding vortex ring, though it will be refreshed after low vibration and be able to detect a vortex ring again. By measuring a period from the start of turbulence generation to the vortex detection repeatedly, we find an exponential distribution of time-of-flights with a non-detection period t 0 and a mean detection period t 1, suggesting a Poisson process. Both periods t 0 and t 1 increase with increasing distance between a generator and a detector. A vortex flight velocity estimated from period t 0 suggests that the sizes of the emitted vortex rings distribute to a range smaller than a generator thickness or a generator vibration amplitude. Vortices are emitted radially from a turbulence region, at least in the direction of oscillator vibration.

Original languageEnglish
Pages (from-to)466-472
Number of pages7
JournalJournal of Low Temperature Physics
Volume171
Issue number5-6
DOIs
Publication statusPublished - 2013 Jun

Fingerprint

Vortex flow
Turbulence
turbulence
vortices
vortex rings
generators
vibration
flight
wire
poisson process
detectors
Wire
Detectors
Gas generators
oscillators
oscillations
rings

Keywords

  • Quantized vortex
  • Quantum turbulence
  • Superfluid He

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Atomic and Molecular Physics, and Optics
  • Materials Science(all)

Cite this

Time-of-flight measurements of vortices emitted from quantum turbulence in superfluid 4He. / Kubo, H.; Nago, Yusuke; Nishijima, A.; Obara, K.; Yano, H.; Ishikawa, O.; Hata, T.

In: Journal of Low Temperature Physics, Vol. 171, No. 5-6, 06.2013, p. 466-472.

Research output: Contribution to journalArticle

Kubo, H. ; Nago, Yusuke ; Nishijima, A. ; Obara, K. ; Yano, H. ; Ishikawa, O. ; Hata, T. / Time-of-flight measurements of vortices emitted from quantum turbulence in superfluid 4He. In: Journal of Low Temperature Physics. 2013 ; Vol. 171, No. 5-6. pp. 466-472.
@article{c62fb0f841a7454697adf5ad1c912467,
title = "Time-of-flight measurements of vortices emitted from quantum turbulence in superfluid 4He",
abstract = "An oscillating obstacle generates quantum turbulence in superfluids, when vortices remained attached to obstacle surfaces or vortex rings collided with it during oscillation. Turbulence provides a source of vortices; however, the characteristics of these vortices are not clear. In the present work, we report the flight of vortices emitted from quantum turbulence in superfluid 4He at low temperatures, using vibrating wires as a generator and a detector of vortices. A vortex-free vibrating wire can detect only the first colliding vortex ring, though it will be refreshed after low vibration and be able to detect a vortex ring again. By measuring a period from the start of turbulence generation to the vortex detection repeatedly, we find an exponential distribution of time-of-flights with a non-detection period t 0 and a mean detection period t 1, suggesting a Poisson process. Both periods t 0 and t 1 increase with increasing distance between a generator and a detector. A vortex flight velocity estimated from period t 0 suggests that the sizes of the emitted vortex rings distribute to a range smaller than a generator thickness or a generator vibration amplitude. Vortices are emitted radially from a turbulence region, at least in the direction of oscillator vibration.",
keywords = "Quantized vortex, Quantum turbulence, Superfluid He",
author = "H. Kubo and Yusuke Nago and A. Nishijima and K. Obara and H. Yano and O. Ishikawa and T. Hata",
year = "2013",
month = "6",
doi = "10.1007/s10909-012-0723-3",
language = "English",
volume = "171",
pages = "466--472",
journal = "Journal of Low Temperature Physics",
issn = "0022-2291",
publisher = "Springer New York",
number = "5-6",

}

TY - JOUR

T1 - Time-of-flight measurements of vortices emitted from quantum turbulence in superfluid 4He

AU - Kubo, H.

AU - Nago, Yusuke

AU - Nishijima, A.

AU - Obara, K.

AU - Yano, H.

AU - Ishikawa, O.

AU - Hata, T.

PY - 2013/6

Y1 - 2013/6

N2 - An oscillating obstacle generates quantum turbulence in superfluids, when vortices remained attached to obstacle surfaces or vortex rings collided with it during oscillation. Turbulence provides a source of vortices; however, the characteristics of these vortices are not clear. In the present work, we report the flight of vortices emitted from quantum turbulence in superfluid 4He at low temperatures, using vibrating wires as a generator and a detector of vortices. A vortex-free vibrating wire can detect only the first colliding vortex ring, though it will be refreshed after low vibration and be able to detect a vortex ring again. By measuring a period from the start of turbulence generation to the vortex detection repeatedly, we find an exponential distribution of time-of-flights with a non-detection period t 0 and a mean detection period t 1, suggesting a Poisson process. Both periods t 0 and t 1 increase with increasing distance between a generator and a detector. A vortex flight velocity estimated from period t 0 suggests that the sizes of the emitted vortex rings distribute to a range smaller than a generator thickness or a generator vibration amplitude. Vortices are emitted radially from a turbulence region, at least in the direction of oscillator vibration.

AB - An oscillating obstacle generates quantum turbulence in superfluids, when vortices remained attached to obstacle surfaces or vortex rings collided with it during oscillation. Turbulence provides a source of vortices; however, the characteristics of these vortices are not clear. In the present work, we report the flight of vortices emitted from quantum turbulence in superfluid 4He at low temperatures, using vibrating wires as a generator and a detector of vortices. A vortex-free vibrating wire can detect only the first colliding vortex ring, though it will be refreshed after low vibration and be able to detect a vortex ring again. By measuring a period from the start of turbulence generation to the vortex detection repeatedly, we find an exponential distribution of time-of-flights with a non-detection period t 0 and a mean detection period t 1, suggesting a Poisson process. Both periods t 0 and t 1 increase with increasing distance between a generator and a detector. A vortex flight velocity estimated from period t 0 suggests that the sizes of the emitted vortex rings distribute to a range smaller than a generator thickness or a generator vibration amplitude. Vortices are emitted radially from a turbulence region, at least in the direction of oscillator vibration.

KW - Quantized vortex

KW - Quantum turbulence

KW - Superfluid He

UR - http://www.scopus.com/inward/record.url?scp=84878011423&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84878011423&partnerID=8YFLogxK

U2 - 10.1007/s10909-012-0723-3

DO - 10.1007/s10909-012-0723-3

M3 - Article

VL - 171

SP - 466

EP - 472

JO - Journal of Low Temperature Physics

JF - Journal of Low Temperature Physics

SN - 0022-2291

IS - 5-6

ER -