Research

Current research interests:

I am currently interested in quantum turbulence and vortex dynamics in helium superfluids. Compared with classical fluids, vortices in helium superfluids (in the superfluid component) are very stable and have a fixed circulation. A small vortex core size makes it possible to use the vortex filament model and Biot-Savart equation to determine the vortex dynamics. My numerical research is connected to the experiments done especially by the ROTA group. However, they also relate to experiments conducted, for example, in Manchester, Lancaster, and Osaka.

Some active projects:

Decay of quantum turbulence and the role of Kelvin-waves, especially in the zero temperature limit.
Spin-down of the superfluid component after a sudden stop of rotation.
Twisted vortex state and propagating vortex front.
Turbulence generated by vibrating wires, spheres, and forks.

For more information about some other projects I refer to the helium theory page of the Low Temperature Laboratory.

Spin-down of cubic container at T = 0.22T_c in superfluid ³He-B.

PhD thesis:

Title: Simulations of topological defects and impurities in superfluid ³He.
Photos from the dissertation and from the Karonkka.

Master's thesis:

Title: Superfluid density of ³He-B in aerogel using an inhomogeneous scattering model.

Teaching:

Instructed PhD Thesis:

2012: Janne Karimäki,"Structure and dynamics of vortices in superfluid helium-3".

Instructed Bachelor Thesis:

2010: Niklas Hietala, "Quantized vortices and their polarization during spin-down" (in Finnish "Kvantittuneet virtauspyörteet ja niiden polarisaatio spin downissa").
2008: Jonne Koski, "Vortex ring instability and Kelvin waves in helium-3 superfluid" (in Finnish "Vorteksirenkaan epästabiilisuus ja Kelvin-aallot helium-3 supranesteessä").

Publications:

My ResearcherID is E-7147-2013

Check my arXiv submissions

2013:

A. Baggaley and R. Hänninen: Vortex filament method as a tool for computational visualization of quantum turbulence, arXiv:1305.2753.
R. Hänninen: Dissipation enhancement due to a single vortex reconnection in superfluid helium, arXiv:1303.6852.
J.J. Hosio, V.B. Eltsov, P.J. Heikkinen, R. Hänninen, M. Krusius, and V.S. L'vov: Energy and angular momentum balance in wall-bounded quantum turbulence at very low temperatures, Nat. Commun. 4, 1614 (2013); arXiv:1208.2647.
R. Hänninen and N. Hietala: Identification of Kelvin waves: numerical challenges, J. Low Temp. Phys. 171, 485-496 (2013); arXiv:1208.5403.

2012:

J.M. Karimäki, R. Hänninen, and E.V. Thuneberg: Asymptotic motion of a single vortex in a rotating cylinder, Phys. Rev. B 85, 224519-1-9 (2012); arXiv:1108.5978.

2011:

R. Hänninen: Steady-state spectrum of Kelvin waves on a quantized vortex at finite temperatures, arXiv:1104.4926.
P.M. Walmsley, V.B. Eltsov, P.J. Heikkinen, J.J. Hosio, R. Hänninen, and M. Krusius: Turbulent vortex flow responses at the AB interface in rotating superfluid ³He-B, Phys. Rev. B 84, 184532-1-7 (2011); arXiv:1108.4283.
J.J. Hosio, V.B. Eltsov, R. de Graaf, P.J. Heikkinen, R. Hänninen, M. Krusius, V.S. L'vov, G.E. Volovik: Superfluid vortex front at T → 0: Decoupling from the reference frame, Phys. Rev. Lett. 107, 135302-1-4 (2011); arXiv:1102.4284.
R. Hänninen and W. Schoepe: Dynamical scaling of the critical velocity for the onset of turbulence in oscillatory superflows, J. Low Temp. Phys. 164, 1-4 (2011); arXiv:1103.5007.

2010:

V.B. Eltsov, R. de Graaf, P.J. Heikkinen, J.J. Hosio, R. Hänninen, M. Krusius: Vortex formation and annihilation in rotating superfluid ³He-B at low temperatures, J. Low Temp. Phys. 161, 474-508 (2010).
V.B. Eltsov, R. de Graaf, P.J. Heikkinen, J.J. Hosio, R. Hänninen, M. Krusius, V.S. L'vov: Stability and dissipation of laminar vortex flow in superfluid ³He-B, Phys. Rev. Lett. 105, 125301-1-4 (2010).; arXiv:1005.0546.
V.B. Eltsov, R. Hänninen, and M. Krusius: Vortices and other topological defects in non-equilibrium phase transitions of superfluid ³He, Physica C 470, 803-808 (2010).
R. Hänninen and W. Schoepe: Universal onset of quantum turbulence in oscillating flows and crossover to steady flows, J. Low Temp. Phys. 158, 410-414 (2010), special issue of QFS2009; arXiv:0909.3007.

2009:

R. Hänninen: Rotating inclined cylinder and the effect of the tilt angle on vortices, J. Low Temp. Phys. 156, 145-162 (2009), special issue on Quantum Turbulence; arXiv:0906.0850.
R. Hänninen, V.B. Eltsov, A.P. Finne, R. de Graaf, J. Kopu, M. Krusius, and R.E. Solntsev: Precessing vortex motion and instability in a rotating column of superfluid ³He-B, J. Low Temp. Phys. 155, 98-113 (2009); arXiv:cond-mat/0701647.
V.B. Eltsov, R. de Graaf, R. Hänninen, M. Krusius, R.E. Solntsev, V.S. L'vov, A.I. Golov, and P.M. Walmsley: Turbulent dynamics in rotating helium superfluids, in Progress in Low Temperature Physics: Quantum Turbulence, Vol. 16, 45-146 (2009); arXiv:0803.3225.

2008:

R. de Graaf, R. Hänninen, T.V. Chagovets, V.B. Eltsov, M. Krusius, and R.E. Solntsev: The dynamics of vortex generation in superfluid ³He-B, J. Low Temp. Phys. 153, 197-227 (2008), special issue related to ULTI2008 symposium; arXiv:0708.3003.
R. Hänninen and W. Schoepe: Universal critical velocity for the onset of turbulence of oscillatory superfluid flow, J. Low Temp. Phys. 153, 189-196 (2008), special issue related to ULTI2008 symposium; arXiv:0811.2861. Preliminary analysis is available in: Frequency dependence of the critical velocity of a sphere oscillating in superfluid Helium-4, (2008); arXiv:0801.2521.
V.B. Eltsov, R. de Graaf, R. Hänninen, M. Krusius, and R.E. Solntsev: Experiments on the twisted vortex state in superfluid ³He-B, J. Low Temp. Phys. 150, 373-383 (2008), proceedings of QFS2007; arXiv:0706.2080.

2007:

V.B. Eltsov, A.I. Golov, R. de Graaf, R. Hänninen, M. Krusius, V.S. L'vov and R.E. Solntsev: Quantum turbulence in a propagating superfluid vortex front, Phys. Rev. Lett. 99, 265301-1-4 (2007); arXiv:0708.1095.
R.E. Solntsev, R. de Graaf, V.B. Eltsov, R. Hänninen, and M. Krusius: Dynamic remnant vortices in superfluid ³He-B, J. Low Temp. Phys. 148, 311-316 (2007), proceedings of QFS2006; arXiv:cond-mat/0607323.
Shoji Fujiyama, Risto Hänninen, and Makoto Tsubota: Vortex Pinning to a Solid Sphere in Helium II, J. Low Temp. Phys. 148, 263-267 (2007), proceedings of QFS2006.
R. Hänninen, M. Tsubota, and W.F. Vinen: Generation of turbulence by oscillating structures in superfluid helium at very low temperatures, Phys. Rev. B 75, 064502-1-12 (2007); arXiv:cond-mat/0610224. Picture from simulations was selected as one of the PRB Kaleidoscope Images: February 2007.

2006:

A.P. Finne, V.B. Eltsov, R. Hänninen, N.B. Kopnin, J. Kopu, M. Krusius, M. Tsubota, and G.E. Volovik: Dynamics of vortices and interfaces in superfluid ³He, Rep. Prog. Phys. 69, 3157-3230 (2006); arXiv:cond-mat/0606619.
C.F. Barenghi, R. Hänninen, and M. Tsubota: Anomalous translational velocity of vortex ring with finite-amplitude Kelvin waves, Phys. Rev. E 74, 046303-1-5 (2006); arXiv:physics/0604008.
V.B. Eltsov, A.P. Finne, R. Hänninen, J. Kopu, M. Krusius, M. Tsubota, and E. V. Thuneberg: Twisted vortex state, Phys. Rev. Lett. 96, 215302-1-4 (2006); arXiv:cond-mat/0602667. Picture from simulations was selected as cover caption figure for June 2, 2006 issue of PRL.
A.P. Finne, V.B. Eltsov, G. Eska, R. Hänninen, J. Kopu, M. Krusius, E. V. Thuneberg, and M. Tsubota: Vortex multiplication in applied flow: a precursor to superfluid turbulence, Phys. Rev. Lett. 96, 085301-1-4 (2006); arXiv:cond-mat/0502119.
R. Hänninen, A. Mitani, and M. Tsubota: Simple pinning model for vibrating wire turbulence in superfluid helium at zero temperature, AIP Conference Proceedings, 850, 217-218 (2006); Proceedings of LT24.
A. Mitani, R. Hänninen, and M. Tsubota: Critical velocity for superfluid turbulence at high temperatures, AIP Conference Proceedings, 850, 221-222 (2006); Proceedings of LT24.

-2005:

R. Hänninen, A. Mitani, and M. Tsubota: Superfluid ³He-B vortex simulations inside a rotating cylinder, J. Low Temp. Phys. 138, 589-594 (2005); Proceedings of QFS2004.
R. Hänninen and E.V. Thuneberg: Calculation of NMR properties of solitons in superfluid ³He-A, Phys. Rev. B 68, 094504-1-11 (2003); arXiv:cond-mat/0103052.
R. Hänninen, R. Blaauwgeers, V.B. Eltsov, A.P. Finne, M. Krusius, E.V. Thuneberg, and G.E. Volovik: Structure of surface vortex sheet between two rotating ³He superfluids, Phys. Rev. Lett. 90, 225301-1-4 (2003); arXiv:cond-mat/0303343.
R. Hänninen and E.V. Thuneberg: Model of inhomogeneous impurity distribution in Fermi superfluids, Phys. Rev. B 67, 214507-1-11 (2003); arXiv:cond-mat/0301154.
J. Kopu, R. Hänninen, and E.V. Thuneberg: One-dimensional textures and critical velocity in superfluid ³He-A, Phys. Rev. B 62, 12374-12380 (2000); arXiv:cond-mat/0003210.
R. Hänninen and E.V. Thuneberg: Superfluid density for ³He in aerogel assuming inhomogeneous scattering, Physica B 284, 303-304 (2000); Proceedings of LT22.
R. Hänninen, T. Setälä, and E.V. Thuneberg: Homogeneous scattering model for impure superfluid ³He, Physica B 255, 11-18 (1998); pdf-eprint.

Conference talks:

Kelvin waves: identification and dynamics, 30 min invited talk.
European Workshop on Superfluid Turbulence from the Perspective of Numerics: Modeling, Methods and Challenges, Lyon, France, November 26-28, 2012.
Kelvin-wave spectrum of a pinned vortex, 20 min invited talk.
International Conference on Quantum Fluids and Solids, Lancaster, UK, August 15-21, 2012.
Vortex filament simulations in the zero temperature limit: Kelvin wave cascade, 30 min talk.
Smolenice Workshop of the European Microkelvin Collaboration, Smolenice, Slovakia, March 14-18, 2011.
Numerical studies of superfluid spin down from rotation, 15 min talk.
QFS2010 Satellite: Quantum Turbulence, Grenoble, France, August 7, 2010.
Numerical studies of superfluid spin down from rotation, 30 min talk.
Symposia on Superfluids under Rotation: Vortices, Superfluid Dynamics, and Quantum Turbulence, Lammi, Finland, April 11-16, 2010.
Spin-down response of rotating superfluids: laminar or turbulent?, 30 min invited talk.
Condensed Matter and Materials Physics, CMMP09, Warwick, UK, December 15-17, 2009.
Universal onset of quantum turbulence in oscillating flows and crossover to steady flows, 15 min talk.
Quantum Turbulence Workshop in QFS2009, Evanston, Illinois, USA, August 10, 2009.
Vortex states in an inclined cylinder, 20 min invited talk.
International Symposium on Quantum Fluids and Solids, QFS2009, Evanston, Illinois, USA, August 5-11, 2009.
Simulations on vibrating sphere and tilted rotating cylinder, 30 min invited talk.
Workshop on Topics in Quantum Turbulence, Trieste, Italy, March 16-20, 2009.
Coupling between different kelvin waves: cascade and inverse cascade, 30 min invited talk.
Workshop on Topics in Quantum Turbulence, Trieste, Italy, March 16-20, 2009.
Quantum turbulence: the role of numerical simulations, 40 min invited talk.
The 2nd International Workshop on Photosynthetic Antennae and Coherent Phenomena, Osaka, Japan, December 14-16, 2007.
Transition to turbulence and its dependence on vortex damping in superfluids, 26 min contributed talk.
The 2006 APS Division of Fluid Dynamics, 59th Annual Meeting, Tampa Bay, Florida, USA, November 19-21, 2006.
Vortex dynamics and quantum turbulence in superfluid ³He under rotation: propagating vortex front, 60 min talk.
Workshop on Quantum Turbulence, Gainesville, Florida, USA, November 16-17, 2006.
Numerical simulations on vibrating wire turbulence in superfluid helium, 20 min contributed talk.
International Symposium on Quantum Fluids and Solids, QFS2006, Kyoto University, Kyoto, Japan, August 1-6, 2006.
Vortex dynamics in helium superfluids, 15 min contributed talk.
The 61st Annual Meeting of the Physical Society of Japan, Matsuyama, Japan, March 27-30, 2006.
Propagating twisted vortex front in superfluid ³He-B under rotation, 25 min invited talk.
International Workshop on Photosynthetic Antennae and Coherent Phenomena, Osaka City University, Osaka, December 6-8, 2005.
Vibrating wire turbulence in superfluid helium: simple pinning model, 15 min contributed talk.
The 2005 Autumn Meetings of the Physical Society of Japan, Doshisha University, Japan, September 19-22, 2005.
Stability of quantized vortices under rotation: helically twisted vortex bundle, 20 min contributed talk.
The International Conference on Ultra-Low Temperature Physics, Gainesville, Florida, USA, August 18-20, 2005.
Vortex stability under rotation, 30 min talk.
Superfluids under Rotation, Manchester, United Kingdom, April 4-8, 2005.
Quantum turbulence around vibrating wire, 15 min contributed talk.
The 60th Annual Meeting of the Physical Society of Japan, Tokyo Univ. of Science, Japan, March 24-27, 2005.
Superfluid ³He-B turbulence inside rotating cylinder, 20 min contributed talk.
Vortex and Turbulence in Classical and Quantum Fluids, Kyoto, Japan, October 24-25, 2004.
Superfluid ³He-B turbulence under rotation, 15 min contributed talk.
The 2004 Autumn Meetings of the Physical Society of Japan, Aomori University, Japan, September 12-15, 2004.
Vortices at the A-B phase boundary in superfluid ³He, 30 min talk.
International Workshop on Superfluidity under Rotation 2003, Nikko, Japan, May 13-17, 2003.
Vortices at the A-B phase boundary in superfluid ³He, 25 min contributed talk.
COSLAB school: Patterns of Symmetry Breaking, Cracow, Poland, September 15-29, 2002.
Vortices at the A-B phase boundary in superfluid ³He, 25 min contributed talk.
Low Temperature Physics Winter School, Kevo, Finland, April 20-26, 2002.
NMR spectrum of a soliton in ³He-A, 20 min contributed talk.
International Symposium on Quantum Fluids and Solids, QFS2001, Konstanz, Germany, July 22-27, 2001.

Home

Research

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Photos

Current research interests:

Some active projects:

PhD thesis:

Master's thesis:

Teaching:

Instructed PhD Thesis:

Instructed Bachelor Thesis:

Publications:

2013:

2012:

2011:

2010:

2009:

2008:

2007:

2006:

-2005:

Conference talks:

Home

Research

CV

Hobbies

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