Free Surface of a Rotating HeII Film

1973 ◽  
Vol 51 (21) ◽  
pp. 2283-2286 ◽  
Author(s):  
E. Vittoratos ◽  
M. W. Cole ◽  
P. P. M. Meincke
Keyword(s):  
Thin Films ◽  
Free Surface ◽  
Superfluid Helium ◽  
Vortex Line ◽  
Rotational Frequency ◽  
Experimental Results ◽  
Quantized Vortex ◽  
Bulk Liquid ◽  
Vapor Interface ◽  
Vortex Lines

Stimulated by recent conflicting experimental results, we have investigated the properties of quantized vortex lines in thin films of superfluid helium. The shape of the liquid–vapor interface in the presence of a single line is calculated. The depression of the interface ("dimple") that results is considerably smaller for the film than for the bulk liquid. The critical rotational frequency for the appearance of the first vortex line is only slightly reduced below the bulk value.

Condensation ofHe3Atoms onto Quantized Vortex Lines in Superfluid Helium

1975 ◽  
Vol 35 (14) ◽  
pp. 957-960 ◽  
Author(s):  
R. M. Ostermeier ◽  
E. J. Yarmchuk ◽  
W. I. Glaberson
Keyword(s):  
Superfluid Helium ◽  
Quantized Vortex ◽  
Vortex Lines

scholarly journals Quantized Vortex Rings and Loop Solitons

2020 ◽  
Vol 201 (1-2) ◽  
pp. 11-17
Author(s):  
P. J. Green ◽  
M. J. Grant ◽  
J. W. Nevin ◽  
P. M. Walmsley ◽  
A. I. Golov
Keyword(s):  
Vortex Ring ◽  
Vortex Line ◽  
Quantum Turbulence ◽  
Temperature Limit ◽  
Quantized Vortex ◽  
Vortex Rings ◽  
Zero Temperature ◽  
Vortex Lines ◽  
Small Vortex ◽  
Vortex Filament Model

Abstract The vortex filament model is used to investigate the interaction of a quantized vortex ring with a straight vortex line and also the interaction of two solitons traveling in opposite directions along a vortex. When a ring reconnects with a line, we find that a likely outcome is the formation of a loop soliton. When they collide, loop solitons reconnect as they overlap each other producing either one or two vortex rings. These simulations are relevant for experiments on quantum turbulence in the zero temperature limit where small vortex rings are expected to be numerous. It seems that loop solitons might also commonly occur on vortex lines as they act as transient states between the absorption of a vortex ring before another ring is emitted when the soliton is involved in a reconnection.

Thermocapillary Effects in Laser Direct-Write Metallization

1990 ◽  
Vol 201 ◽  
Author(s):  
Peter E. Price ◽  
Michael Stuke ◽  
Klavs F. Jensen
Keyword(s):  
Thin Films ◽  
Free Surface ◽  
Qualitative Agreement ◽  
Experimental Results ◽  
Palladium Acetate ◽  
Direct Write ◽  
Marangoni Flow ◽  
Direct Writing ◽  
Surface Profiles ◽  
Laser Direct Write

AbstractA model describing melting and thermocapillary (or Marangoni) flow in laser irradiated thin films is presented. The free surface formulation leads to predictions of surface profiles that are in qualitative agreement with experimental observations. Additional experimental results for direct-writing of palladium from palladium acetate films demonstrate the influence of thermocapillary effects on the dynamics of the process.

scholarly journals Bubbles in superfluid helium containing six and eight electrons: Soft, quantum nanomaterial

2021 ◽  
Vol 7 (28) ◽  
pp. eabi7128
Author(s):  
Neha Yadav ◽  
Prosenjit Sen ◽  
Ambarish Ghosh
Keyword(s):  
Superfluid Helium ◽  
Self Assembly ◽  
Short Range ◽  
Soft Materials ◽  
The Self ◽  
Bulk Liquid ◽  
Helium 4 ◽  
Vortex Lines ◽  
Cavitation Threshold

The role of quantum fluctuations in the self-assembly of soft materials is relatively unexplored, which could be important in the development of next-generation quantum materials. Here, we report two species of nanometer-sized bubbles in liquid helium-4 that contain six and eight electrons, forming a versatile, platform to study self-assembly at the intersection of classical and quantum worlds. These objects are formed through subtle interplay of the short-range electron-helium repulsion and easy deformability of the bulk liquid. We identify these nanometric bubbles in superfluid helium using cavitation threshold spectroscopy, visualize their decoration of quantized vortex lines, and study their creation through multiple methods. The objects were found to be stable for at least 15 milliseconds at 1.5 kelvin and can therefore allow fundamental studies of few-body quantum interactions under soft confinements.

Detection of quantized vortex lines in superfluid helium at known pinning sites

1974 ◽  
Vol 49 (2) ◽  
pp. 147-148 ◽  
Author(s):  
S.R. Jost ◽  
E.L. Bogatin ◽  
J.C. Weaver
Keyword(s):  
Superfluid Helium ◽  
Quantized Vortex ◽  
Vortex Lines

Synthesis of Nanocomposite thin film Ti/Al Multilayers and Ti-Aluminides

1996 ◽  
Vol 457 ◽  
Author(s):  
R. Banerjee ◽  
X. D. Zhang ◽  
S. A. Dregia ◽  
H. L. Fraser
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Layer Thickness ◽  
Thermodynamic Model ◽  
Interfacial Reactions ◽  
Experimental Results ◽  
Structural Transitions ◽  
Nanocomposite Thin Film ◽  
Multilayered Thin Films

ABSTRACTNanocomposite Ti/Al multilayered thin films have been deposited by magnetron sputtering. These multilayers exhibit interesting structural transitions on reducing the layer thickness of both Ti and Al. Ti transforms from its bulk stable hep structure to fee and Al transforms from fee to hep. The effect of ratio of Ti layer thickness to Al layer thickness on the structural transitions has been investigated for a constant bilayer periodicity of 10 nm by considering three different multilayers: 7.5 nm Ti / 2.5 nm Al, 5 nm Ti / 5 nm Al and 2.5 nm Ti / 7.5 nm Al. The experimental results have been qualitatively explained on the basis of a thermodynamic model. Preliminary experimental results of interfacial reactions in Ti/Al bilayers resulting in the formation of Ti-aluminides are also presented in the paper.

scholarly journals Mathematical modelling of the overflowing cylinder experiment

2003 ◽  
Vol 474 ◽  
pp. 275-298 ◽  
Author(s):  
P. D. HOWELL ◽  
C. J. W. BREWARD
Keyword(s):  
Free Surface ◽  
Surfactant Concentration ◽  
Dynamic Properties ◽  
Vertical Cylinder ◽  
Surfactant Solution ◽  
Surface Concentration ◽  
Experimental Results ◽  
Surface Velocity ◽  
Experimental Apparatus ◽  
Finite Distance

The overflowing cylinder (OFC) is an experimental apparatus designed to generate a controlled straining flow at a free surface, whose dynamic properties may then be investigated. Surfactant solution is pumped up slowly through a vertical cylinder. On reaching the top, the liquid forms a flat free surface which expands radially before over flowing down the side of the cylinder. The velocity, surface tension and surfactant concentration on the expanding free surface are measured using a variety of non-invasive techniques.A mathematical model for the OFC has been previously derived by Breward et al. (2001) and shown to give satisfactory agreement with experimental results. However, a puzzling indeterminacy in the model renders it unable to predict one scalar parameter (e.g. the surfactant concentration at the centre of the cylinder), which must be therefore be taken from the experiments.In this paper we analyse the OFC model asymptotically and numerically. We show that solutions typically develop one of two possible singularities. In the first, the surface concentration of surfactant reaches zero a finite distance from the cylinder axis, while the surface velocity tends to infinity there. In the second, the surfactant concentration is exponentially large and a stagnation point forms just inside the rim of the cylinder. We propose a criterion for selecting the free parameter, based on the elimination of both singularities, and show that it leads to good agreement with experimental results.

Sign in / Sign up

Export Citation Format

Share Document