Study of waves and inertia mass of quantized vortices in superfluid helium-4

2014 Fiscal Year Final Research Report

• Project/Area Number: 23340108
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Osaka City University
• Principal Investigator: YANO Hideo 大阪市立大学, 大学院理学研究科, 准教授 (70231652)
• Project Period (FY): 2011-04-01 – 2015-03-31
• Keywords: 流体力学 / 超流動ヘリウム / 量子渦 / 量子乱流 / 量子流体力学

Outline of Final Research Achievements

We report the results obtained in the present study as follows, for the purpose of investigating vortex motions in superfluid helium by using novel characteristics of a quantized vortex.
(1) Quantized vortex rings can be produced by vibrating motions of an object immersed in superfluid helium, emitting in random directions. (2) The diameters of vortex rings, estimated from the velocities of the rings, are distributed from 0.2 to 1 micro meter, suggesting that vortex rings cascade to smaller rings by reconnection between vortices. (3) Vortex rings are emitted radially from a point source. (4) The diameters of vortex rings are limited to sizes smaller than a vibrating amplitude of an object. (5) Simulations of vortex emissions by an oscillating sphere reveal that vortex rings are emitted anisotropically in directions. (6) The direct measurements of vortex wave spectrums require new methods of attaching vortices between a vibrating object and a probe.

Free Research Field

超低温物理学