Chair: Luc Damé, Service d'Aéronomie du CNRS, Verrières & LESIA, Observatoire de Paris-Meudon, France
Co-Chair, Vincenzo Andretta, INAF-Osservatorio Astronomico di Capodimonte, Napoli, Italy
Members:
- Jean-Philippe Amans, GEPI, Observatoire de Paris-Meudon, France
- Carsten Denker, AIP, Potsdam, Germany
- Jean-Laurent Dournaux, GEPI, Observatoire de Paris-Meudon, France
- Serge Koutchmy, IAP, Paris, France
- Sergey Kuzin, Lebedev, Moscow, Russia
- Philippe Lamy, LAM, Marseille, France
- Jean-Marie Malherbe, LESIA, Observatoire de Paris-Meudon, France
- André Preumont, Université Libre de Bruxelles, Belgium
A group for the scientific justification and realization of the first medium-size solar facility at Dome C:
[WEB SITE STILL UNDER CONSTRUCTION...]
Figure 1: Open configuration (structure in carbon-epoxy's tubes ) of ADSIIC (the Antarctica Demonstrator of Solar Interferometric Imaging and Coronagraphy), a 3 off-axis telescopes interferometer made of Ø500 mm (or beter: 700 mm) primary mirrors in SiC (secondaries in Si) allowing both high spatial resolution and coronagraphy at Concordia. ADSIIC 3-telescopes interferometer itself is a step towards the 4 Meter Interferometer (FOURMI) with 9 telescopes (and a baseline of 4.3 m). ADSIIC (and FOURMI) are planned to be installed on a high platform at 30 from the ground allowing permanent observations above most of the ground turbulent layer (seeing better than 0.5").
Figure 2: Illustration of the ultimate solar facility for Dome C / Concordia: the 4 Meter Interferometer (FOURMI) with 9 telescopes (and a baseline of 4.3 m).
Figure 3: Two of the Open Tower Concepts of 30 m studied for ADSIIC at Dome C / Concordia station, allowing permanent observations above most of the ground turbulent layers (seeing better than 0.5"). These towers are dimensioned for charges of 20 tons and their central platform is interchangeable (Summer-Winter or maintenance for example) - note the three engines on top to raise the platform. Moreover, all elements are assembly of 6 m tubes in order to fit in containers for transport considerations to Dome C. Analysis are still underway (and a breadboard for wind incidence studies is under consideration) but stabilities are excellent already (note the small green bars to shift resonances): in the 7-8 Hz.
Figure 4: Animation showing the raising of the platform (for maintenance, instrumentation changes, etc.). This is possible thanks to the 3 engines shown on top the external platform.
Figure 5 (pass the mouse over to start the movie): Illustration of the spectacular effect on tower's oscillations-vibrations damping of an extra 1% "free" mass on top of a tower. We intend to use this "auto-stabilization pendulum" effect on our tower by adding an extra mass under the telescope platform (in the mount?). Study is underway (design, analysis and implementation on the tower's breadboard). Movie courtesy of André Preumont, Active Structures Laboratory, ULB, Bruxelles, Belgium. (If loading problems, movie available in compressed form: tower-damping.mpg.zip).
[WEB SITE UNDER CONSTRUCTION]
Usefull links:
Recent presentations of ADSIIC objectives and implementation and of the 30 m Tower design progresses are available on the web site of the ARENA Catania workshop of September 2008: