| VKS turbulent dynamos |
| Slide 2 |
| A scientific questionÉ |
| William Gilbert (1600) | |
| Gauss (1835) |
| Polarity reversals |
| ~800 reversals | |
| period Å (100-300) x 1000 years | |
| 5 000- 10 000 for a reversal | |
| Last one 780 000 yrs ago |
| A fluid dynamo ? |
| Larmor 1919 | |
| Instability conditions |
| Existing experimental fluid dynamos |
| Non-constrained dynamo |
| Von K‡rm‡n Flows |
| How to reach high Rm ? |
| From VKS1 (1999 - 2003) to VKS2 (2005 - É) |
| Slide 12 |
| VKS2 |
| VKS2 |
| Slide 15 |
| stationary dynamo F1 = F2 |
| geometry |
| geometry |
| geometry |
| geometry |
| a turbulent dynamo |
| Slide 22 |
| bifurcation onset |
| bifurcation onset |
| bifurcation onset |
| a dynamo precursor ? |
| Slide 27 |
| a phase space |
| a phase space |
| a variety of regimes |
| Slide 31 |
| reversals |
| magnetic field reversals (16/22) |
| Slide 34 |
| oscillating dynamos |
| dynamo bursts |
| dynamo bursts |
| Slide 38 |
| Neighbouring dynamical regimes |
| Slide 40 |
| Slide 41 |