3rd ARENA Conference

1
ALADDIN Nulling Instrument
Marc Barillot, Vincent Coudé du Foresto, Jean
Surdej, Olivier Absil, Claude Jamar, Emmanuel Di
Folco
2
ALADDIN system

• L-band observations from Dome C
• Dedicated to exozodi characterisations
• 2-telescope rotating interferometer
• Nulling instrument

3
Nulling interferometry

• Strong rejection of starlight 10-4
• Instrumental symmetry and control
• OPD accuracy nm
• dispersion matching nm
• amplitude matching
• polarisation
• Atmosphere is part of the instrument
• RT controls driven by atmosphere
• Heritage VLTI/GENIE study for ESA/ESO

4
From GENIE to ALADDIN
Dispersion Sensor
Spectros detectors cryostats
OPD loop
K
L
L
Intensity loop
Disp. loop
Science Beam combiner
Intensity Sensor
Fast DLs
K-band Fringe Sensor
Beams inputs
H-bandFringe Sensor
Intensity actuators
APS
V to H folding
5
Conceptual ALADDIN instrument
APS
Moderate volume Moderate power consumption Moderat
e data rate
Intensity actuators
Tip-Tilt Sensors
OPD Sensor
Science Detector
OPD Detector
Science Beam Combiner

• Fast ODL

6
ALADDIN Environment

• Fully automatic / Remote controlled instrument
• Complete validation in temperate site
• Human intervention within Concordia station
• Regular roomspace _at_ Concordia (no clean rooms !)
• Extensive expertise of space industry in those
  matters
• Environmental impact conventional
• Fully conventional technology
• In operation, always inside cryostat

7
Development maturity

• MAI² heritage
• Nulling level and stability demo.
• Unpolarised polychromatic source
• PERSEE heritage
• Stability demo with perturbations
• Relevant / available for ALADDIN

1.7 10-5 nulling 6 10-7 rms stability (1h)

• VLTI/GENIE Heritage
• Existing preliminary design data package
• GENIEsim software
• Most of GENIE Team available

8
Development schedule
2009 Proposal for Feasibility-Def Study
2010-11 Feasibility-Prel. Def Study Cost
2012-13 Detailed Design Study
2014-15 Assembly and integration
2016 Validation on temperate site
2017 Integration _at_ Dome C
2018-19 2 exozodi surveys
2020 End of programme
9
Conclusion

• Realistic reasonable nulling instrument
  thanks to Dome-C atmosphere and design
• Antarctica Compatibility like any other
  instrument
• Strong heritage experienced team
• Ready for a Preliminary Design Study