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Author Zemma, E.; Luzuriaga, J.
Title Turbulent Flow Around an Oscillating Body in Superfluid Helium: Dissipation Characteristics of the Nonlinear Regime Type Journal Article
Year 2013 Publication Journal of Low Temperature Physics Abbreviated Journal J. Low Temp. Phys.
Volume 172 Issue 3-4 Pages (down) 256-265
Keywords Quantum fluids; Turbulence; Superfluid helium; Nonlinear oscillator; Vibrating paddle; Critical velocity
Abstract By examining the resonance curves of an oscillator submerged in superfluid liquid helium, it is found that their shape is affected by two distinct dissipation regimes when the amplitude is large enough to generate turbulence in the liquid. In a resonance curve, the central part close to resonance, may be in a turbulent regime, but the response is of much lower amplitude away from the resonance frequency, so that the oscillation can still be in the linear regime for frequencies not exactly at resonance. This introduces an ambiguity in estimating the inverse quality factor Q −1 of the oscillator. By analyzing experimental data we consider a way of matching the two ways of estimating Q −1 and use the information to evaluate the frictional force as a function of velocity in a silicon paddle oscillator generating turbulence in the superfluid.
Address
Corporate Author Thesis
Publisher Springer US Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2291 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 662
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Author D'Anna, G.; Andre, M.-O.; Benoit, W.; Rodriguez, E.; Rodriguez, D.S.; Luzuriaga, J.; Wasczak, J.V.
Title Flux-line response in 2H-NbSe2 investigated by means of the vibrating superconductor method Type Journal Article
Year 1993 Publication Physica C Abbreviated Journal Physica C
Volume 218 Issue 1-2 Pages (down) 238-244
Keywords
Abstract We measure transverse AC losses in the low- and high-amplitude regime of 2H-NbSe2 single crystals using vibrating superconductor methods. The measurements are sensitive to small deviations of the critical state. The data constitute evidence for a peak effect of the critical current as a function of the temperature in this compound. We construct in the H-T phase diagram the ''peak-effect'' line which is supposed to mark an abrupt cross-over in the vortex-pinning regime.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4534 ISBN Medium
Area Expedition Conference
Notes ISI:A1993MM29800033 Approved no
Call Number BT @ hernan @ Serial 253
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Author Zemma, E.; Luzuriaga, J.
Title Measurements of Turbulence Onset and Dissipation in Superfluid Helium with a Silicon Double Paddle Oscillator Type Journal Article
Year 2012 Publication Journal of Low Temperature Physics Abbreviated Journal J. Low Temp. Phys.
Volume 166 Issue 3-4 Pages (down) 171-181
Keywords
Abstract We have studied experimentally the response of a silicon single crystal double paddle oscillator submerged in superfluid helium from the lambda point to 1.55 K. Measuring the resonance frequency and dissipation on three modes of this high Q system allows us to study the dissipation at the onset of turbulence in the flow around the paddle. The critical velocity V c for turbulence onset decreases with temperature. If we use the density of the normal component of the superfluid to obtain a Reynolds number Re associated with V c we find a value which is largely temperature independent. This result is different from the behavior previously found by other authors below 1 K, where the quantized vorticity (extrinsic nucleation) is observed at velocities more than an order of magnitude greater. In our temperature range, we conclude that the transition is governed by the normal fraction acting as a classical fluid. The laminar regime shows a dissipation that is proportional to the viscous drag calculated by well known formulas for an object oscillating in a liquid. We also find a decrease in resonance frequency in the turbulent regime which is clearly observed but hard to reproduce from run to run.
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Language Summary Language Original Title
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ISSN 1573-7357 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ hernan @ Serial 648
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Author Herbsommer, J.A.; Luzuriaga, J.; Cheong, S.-W.
Title Vortex glass melting in single crystal La1.825 Sr0.075CuO4 Type Journal Article
Year 1996 Publication Physica C Abbreviated Journal Physica C
Volume 258 Issue 1-2 Pages (down) 169-174
Keywords Copper compounds; Crystal lattices; Frequency response; Glass; Magnetic field measurement; Magnetic permeability measurement; Melting; Phase diagrams; Single crystals; Temperature; Vortex flow; AC susceptibility; Cuprates; Pinned flux lattice; Oxide superconductors
Abstract The vortex phase diagram in single crystalline La1.85Sr0.075CuO4 has been studied using an AC-susceptibility technique. A peak in the out-of-phase (x?) component of the susceptibility indicates a transition from a pinned flux lattice (FLL) to an unpinned one. This peak is frequency dependent for all the values of the magnetic field measured (0.01 to 4 T), and this, as well as the general behavior found in the cuprates, has prompted us to interpret our data as evidence for a vortex-glass to liquid transition in the FLL. The activation energies obtained can be fitted to a theory developed by Vinokur et al. Measurements with the magnetic field at an angle with the Cu-O planes may also be understood qualitatively within this framework.
Address AT and T Bell Laboratories, Murray Hill, NJ, United States
Corporate Author Thesis
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 09214534 (ISSN) ISBN Medium
Area Expedition Conference
Notes Cited By (since 1996): 2; Export Date: 28 April 2009; Source: Scopus; CODEN: PHYCE; doi: 10.1016/0921-4534(95)00812-8; Language of Original Document: English; Correspondence Address: Luzuriaga, J.; Centro At Approved no
Call Number BT @ luzuriag @ Serial 483
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Author Herbsommer, J.A.; Luzuriaga, J.; Civale, L.; Nieva, G.; Pasquini, G.; Lanza, H.; Levy, P.
Title Angular variation of pinning near the irreversibility temperature in single crystal Y Ba2Cu3O7-? with splayed columnar defects Type Journal Article
Year 1998 Publication Physica C Abbreviated Journal Physica C
Volume 304 Issue 1-2 Pages (down) 112-118
Keywords Columnar defects; Critical current density; Flux pinning; Pinning force; Anisotropy; Critical current density (superconductivity); Crystal defects; Single crystals; Columnar defects; Flux pinning; Yttrium barium copper oxides
Abstract We have studied vortex pinning through ac susceptibility measurements in single crystals of YBCO with columnar defects (CDs). The CDs have 0, 10 and 20 splay angle and average direction 108 off the c-axis. By studying the angular variation we can compensate for the anisotropy and effects of twins, etc. Using a simple expression we can obtain the angular spread when the field direction is outside the splay angle. An increase of pinning when the field direction is inside

the angle defined by the CDs can be attributed to vortex entanglement due to the splay and the suppression of the sliding of double kinks.
Address Departamento de F
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ISSN 09214534 (ISSN) ISBN Medium
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Notes Cited By (since 1996): 10; Export Date: 28 April 2009; Source: Scopus; CODEN: PHYCE; Language of Original Document: English; Correspondence Address: Herbsommer, J.A.; Ctro. Atom. Bariloche Inst. Balseiro; CNEA and UNC 8400 Bariloche, Argentina; References: Civale, L., Marwick, A.D., Worthington, T.K., Kirk, M.A., Thompson, J.R., Krusin-Elbaum, L., Sun, Y., Holtzberg, F., (1991) Phys. Rev. Lett., 67, p. 648; Hwa, T., Doussal, P.L., Nelson, D.R., Vinokur, V.M., (1993) Phys. Rev. Lett., 71, p. 3545; Civale, L., Krusin-Elbaum, L., Thompson, J.R., Wheeler, R., Marwick, A.D., Kirk, M.A., Sun, Y.R., (1994) Phys. Rev. B, 50, p. 4102; Krusin-Elbaum, L., Thompson, J.R., Wheeler, R., Marwick, A.D., Li, C., Patel, S., Shaw, D.T., Ullmann, J., (1994) Appl. Phys. Lett., 64, p. 3331; Hardy, V., Whal, A., Hebert, S., Ruyler, A., Provost, J., Groult, D., Simon, C., (1996) Phys. Rev. B, 54, p. 656; Hardy, V., Ruyter, A., Whal, A., Maignan, A., Groult, D., Provost, J., Simon, C., Noel, H., (1996) Physica C, 257, p. 16; Krusin-Elbaum, L., Marwick, A.D., Wheeler, R., Feild, C., Vinokur, V.M., Leaf, G.K., Palumbo, M., (1996) Phys. Rev. Lett., 76, p. 2563; Prozorov, R., Konczykowski, M., Schmidt, B., Yeshurun, Y., Shaulov, A., Villard, C., Koren, G., (1996) Phys. Rev. B, 54, p. 15530; De La Cruz, F., L Approved no
Call Number BT @ luzuriag @ Serial 517
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Author Schmoranzer, D.; Jackson, M.J.; Luzuriaga, J.
Title On the Non-linear Damping of Mechanical Oscillators in Flows of 4He Type Journal Article
Year 2014 Publication Journal of Low Temperature Physics Abbreviated Journal J. Low Temp. Phys.
Volume 175 Issue 1 Pages (down) 97-103
Keywords Resonator; Non-linear dissipation; Turbulence; Liquid helium
Abstract In the studies of both classical and quantum turbulence, significant attention is devoted to the investigation of the behavior of various submerged resonators. Upon entering the turbulent regime, the oscillators start to experience a significant drag force, which varies non-linearly with velocity. We present an empirical way of modeling such systems, and calculate the expected resonant response of such oscillators near the fundamental frequency as a function of the applied driving force. We apply the model to the crossover from linear to non-linear drag forces and compare with previous models as well as selected experimental data on the transition to turbulence in oscillatory flow of 4He.
Address
Corporate Author Thesis
Publisher Springer US Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2291 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 663
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Author Zemma, E.; Luzuriaga, J.
Title Anomalous Trajectories of H2 Solid Particles Observed Near a Sphere Oscillating in Superfluid Turbulent 4He Type Journal Article
Year 2013 Publication Journal of Low Temperature Physics Abbreviated Journal J. Low Temp. Phys.
Volume 173 Issue 1-2 Pages (down) 71-79
Keywords Quantum fluids; Turbulence; Superfluid helium; Flow visualization; Oscillating sphere
Abstract Using a relatively low cost apparatus, consisting of a glass dewar and a digital camera capable of taking images at 240 frames per second we have observed trajectories of frozen H2 particles which follow the flow of liquid helium below 2 K, around a sphere oscillating at 38 Hz. In some of the images the motion is compatible with laminar flow, while at high amplitudes, where we can reach Reynolds numbers of a few thousand in the normal component, the flow is clearly turbulent. In some of the videos taken we find particles being suddenly accelerated to several times the velocity of the oscillating sphere.
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Corporate Author Thesis
Publisher Springer US Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-2291 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number BT @ pedrazp @ Serial 661
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Author Herbsommer, J.A.; Correa, V.F.; Nieva, G.; Pastoriza, H.; Luzuriaga, J.
Title Vortex dynamics in Bi2Sr2CaCu2O8+δ single crystals with planar defects Type Journal Article
Year 2001 Publication Solid State Communications Abbreviated Journal Solid State Commun.
Volume 120 Issue 2-3 Pages (down) 59-63
Keywords
Abstract We have studied the effects of c-axis correlated planar defects on the vortex lattice of Bi$2$Sr$2$CaCu$8$ single crystals using Bitter decoration, transverse ac permeability and X-ray measurements. Our results show that the low field low temperature phase coherent vortex lattice exhibits anisotropic pinning in the presence of these planar defects. Frequency dependent ac permeability measurements show that the ordered solid-liquid transition is first order as in samples free of correlated defects. However, the melting point is detected only when the excitation field is along the defects.
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Notes Approved no
Call Number BT @ hernan @ herbsommer01 Serial 23
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Author Rodriguez, D.S.; Rodriguez, E.; Luzuriaga, J.; Waszczak, J.V.; Cheong, S.W.
Title Role of anisotropy in the vortex lattice of superconductors high-Q oscillator measurements in 2H-NbSe2 and La1.825Sr.075CuO4 Type Journal Article
Year 1994 Publication Physica C Abbreviated Journal
Volume 229 Issue 1-2 Pages (down) 59-64
Keywords
Abstract Measurements of the response of the flux-line lattice in NbSe2 and La1.825Sr0.075CuO4 show important differences between these two materials. In particular, we have studied the magnetic-field and angular dependence of the response of a high-Q mechanical oscillator in fields of up to 1 T. The features seen in NbSe2 seem to be well explained in terms of a change in the pinning regime, usually termed the ''peak effect'' in the critical current, using the collective-pinning model of Larkin and Ovchivnikov within Ginzburg-Landau anisotropic theory. On the other hand the behavior found in the high-T(c) material LSCO seems to fall naturally into a description which takes into account the possibility of phase transitions in the vortex lattice and the quasi-two-dimensional character of the superconductivity.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0921-4534 ISBN Medium
Area Expedition Conference
Notes ISI:A1994PF49500008 Approved no
Call Number BT @ hernan @ Serial 252
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Author Luzuriaga, J.
Title Even in translation, Richter's 'science' unimpressive Type Journal Article
Year 2005 Publication Physics Today Abbreviated Journal Phys Today
Volume 58 Issue 1 Pages (down) 14-15
Keywords
Abstract
Address Instituto Balseiro, Bariloche, Argentina
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ISSN 00319228 (ISSN) ISBN Medium
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Notes Export Date: 28 April 2009; Source: Scopus; CODEN: PHTOA; doi: 10.1063/1.1881878; Language of Original Document: English; Correspondence Address: Luzuriaga, J.; Centro Atomico Bariloche Bariloche, Argentina Approved no
Call Number BT @ luzuriag @ Serial 508
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