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1. Impact of local turbulence on high-order adaptive optics

Author

Hugo Nowacki, Jean-Baptiste Le Bouquin, Carole Gouvret, Aurélie Marcotto, Sylvie Robbe Dubois, Karine Perraut, Yves Magnard, Alain Delboulbé, Eric Stadler, Sylvain Guieu, Sylvain Rochat, and Didier Maurel

Subjects
FOS: Physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

We present an experiment set to address a standard specification aiming at avoiding local turbulence inside the Coud\'e train of telescopes. Namely, every optical surface should be kept within a 1.5$^\circ$ range around ambient temperature. Such a specification represents an important concern and constraint when developing optical systems for astronomy. Our aim was to test its criticality in the context of the development of the VLTI/NAOMI and VLTI/GRAVITY+ adaptive optics. This experiment has been conducted using the hardware of the future Corrective Optics (CO) of GRAVITY+. Optical measurements were performed in order to observe the evolution of turbulence in front of a flat mirror for which the surface temperature was controlled in a range of $22^\circ$ above ambient temperature. A time-dependent analysis of the turbulence was led along with a spatial analysis. This experiment shows no influence of temperature on local turbulence. It should be noted however that this result is only applicable to the very specific geometry described in this paper, which is representative of an adaptive optics (AO) system located inside the Coud\'e train (facing-down mirror heated on its backface).

Published
2022
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2. SAXO+, a second-stage adaptive optics for SPHERE on VLT: optical and mechanical design concept

Author

Eric Stadler, Emiliano Diolaiti, Laura Schreiber, Fausto Cortecchia, Matteo Lombini, Magali Loupias, Yves Magnard, Adriano De Rosa, Giuseppe Malaguti, Didier Maurel, Gianluca Morgante, Patrick Rabou, Sylvain Rochat, Filomena Schiavone, Luca Terenzi, Fabrice Vidal, Faustine Cantalloube, Éric Gendron, Raffaele Gratton, Julien Milli, David Mouillet, Gaël Chauvin, François Wildi, Jean-Luc Beuzit, and Anthony Boccaletti

Published
2022
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3. HARMONI at ELT: development of the high-contrast module

Author

Laurent Jocou, Patrick Rabou, Thibaut Moulin, Yves Magnard, Adrien Hours, Fabrice Pancher, Sylvain Guieu, Alexis Carlotti, Alain Delboulbé, Maxime Vérove, Eric Stadler, Didier Maurel, Sylvain Rochat, François Hénault, Kjetil Dohlen, Niranjan Thatte, Benoit Neichel, Pascal Vola, Fraser Clarke, Dave Melotte, Matthias Tecza, Hermine Schnetler, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]
Abstract

International audience

Published
2022
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4. MAORY for ELT: preliminary design overview

Author

Angelo Valentini, Luca Terenzi, Edoardo Redaelli, Giorgio Pariani, Estelle Moraux, Demetrio Magrin, Mauro Dolci, Simone Zaggia, Christophe Vérinaud, Noël Ventura, Marie-Hélène Sztefek, Eric Stadler, Marilena Spavone, Laura Schreiber, Paolo Saracco, Bernardo Salasnich, Alain Roux, Frédéric Roussel, Sylvain Rochat, Matteo Aliverti, Marco Riva, Roberto Ragazzoni, Patrick Rabou, Alfio T. Puglisi, Linda Podio, Cédric Plantet, Mauro Patti, Sylvain Oberti, Thibaut Moulin, Gianluca Morgante, Didier Maurel, Enrico Marchetti, Filippo Mannucci, Yves Magnard, Matteo Lombini, Miska Le Louarn, Etienne P. Le Coarer, Mimma Lauria, Sylvain Lafrasse, Paolo La Penna, Laurent Jocou, Francois B. Hénault, Laurence Gluck, Enrico Giro, Italo Foppiani, Giuliana Fiorentino, Daniela Fantinel, Simone Esposito, Gianluca Di Rico, Alain Delboulbe, Adriano De Rosa, Vincenzo De Caprio, Massimo Dall'Ora, Valentina D'Orazi, Giuseppe Cosentino, Fausto Cortecchia, Jean-Jacques Correia, Enrico Cascone, Alexis Carlotti, Davide Greggio, Paolo Grani, Ivan Di Antonio, Andrea Balestra, Natalia Auricchio, Laurence Michaud, Elisabetta Maiorano, Philippe Feautrier, Lorenzo Busoni, Olivier Brissaud, Giovanni Bregoli, Marco Bonaglia, Michele Bellazzini, Andrea Baruffolo, Carmelo Arcidiacono, Guido Agapito, Renata Abicca, Paolo Ciliegi, Emiliano Diolaiti, and ITA

Subjects
Wavefront, Computer science, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, 01 natural sciences, Compensation (engineering), law.invention, 010309 optics, Telescope, law, 0103 physical sciences, Extremely Large Telescope, Astrophysics::Solar and Stellar Astrophysics, Atmospheric turbulence, Astrophysics::Earth and Planetary Astrophysics, Aerospace engineering, business, Adaptive optics, Instrument design, 010303 astronomy & astrophysics
Abstract

MAORY is one of the approved instruments for the European Extremely Large Telescope. It is an adaptive optics module, enabling high-angular resolution observations in the near infrared by real-time compensation of the wavefront distortions due to atmospheric turbulence and other disturbances such as wind action on the telescope. An overview of the instrument design is given in this paper.

Published
2018
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5. NAOMI: a low-order adaptive optics system for the VLT interferometer

Author

Pavel Shchkaturov, Julien Woillez, Angela Cortes, Javier Reyes, Jean-Baptiste Le Bouquin, Norbert Hubin, Paul Jolley, Rob Donaldson, Jean-Jacques Correia, Yves Magnard, F. Delplancke-Ströbele, Marcos Suarez, Laurence Michaud, Thanh Phan Duc, Sebastian Egner, Emmanuel Aller-Carpentier, Miska Le Louarn, J. Quentin, Stefan Huber, T. Moulin, Frédéric Gonté, Luca Pasquini, Luigi Andolfato, Jaime Alonso, Guillermo Valdes, R. Ridings, Reinhold J. Dorn, Didier Maurel, Jean-Philippe Berger, Paul Lilley, Sylvain Rochat, Christophe Dupuy, Alessandro Martis, Alain Roux, Jerome Paufique, J. P. Kirchbauer, Jean-Luc Beuzit, Christophe Verinaud, Alain Delboulbé, and Eric Stadler

Subjects
Physics, Wavefront, Interferometry, Optics, 010308 nuclear & particles physics, business.industry, 0103 physical sciences, Astronomical interferometer, Strehl ratio, business, Adaptive optics, 010303 astronomy & astrophysics, 01 natural sciences
Abstract

The New Adaptive Optics Module for Interferometry (NAOMI) will be developed for and installed at the 1.8-metre Auxiliary Telescopes (ATs) at ESO Paranal. The goal of the project is to equip all four ATs with a low-order Shack– Hartmann adaptive optics system operating in the visible. By improving the wavefront quality delivered by the ATs for guide stars brighter than R = 13 mag, NAOMI will make the existing interferometer performance less dependent on the seeing conditions. Fed with higher and more stable Strehl, the fringe tracker(s) will achieve the fringe stability necessary to reach the full performance of the second-generation instruments GRAVITY and MATISSE.

Published
2016
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6. Oxidative dissolution of ruthenium deposits onto stainless steel by permanganate ions in alkaline medium

Author

Catherine Eysseric, Didier Maurel, and Sébastien Floquet

Subjects
chemistry.chemical_compound, Chemistry, Kinetics, Permanganate, Inorganic chemistry, chemistry.chemical_element, Manganese, Human decontamination, Physical and Theoretical Chemistry, PUREX, Dissolution, Corrosion, Ruthenium
Abstract

During spent nuclear fuel reprocessing ruthenium is liable to form black ruthenium deposits on the stainless steel walls of process equipments. These deposits promote corrosion and can eventually obstruct the off-gas lines. The results of decontamination of 304L stainless steel test specimens covered with RuO(OH)2· x H2O deposits by permanganate ions in alkaline medium are described. The ruthenium deposits were dissolved by oxidation of RuO(OH)2 to RuO4 2− ions, while the permanganate ions were reduced to MnO4 2− ions and then to manganese dioxide MnO2. The parameters affecting the kinetics of oxidative dissolution of these deposits were examined. The results indicate that the oxidative dissolution kinetics depends on the instantaneous surface area of the deposit, and that the dissolution rate increases with the concentrations of MnO4 − and OH− ions.

Published
2008
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7. Effect of ozone on ruthenium species in alkaline medium – Part III: Oxidative dissolution of ruthenium deposits onto stainless steel

Author

Didier Maurel, Sébastien Floquet, Jean-Michel Fulconis, Jacques Delagrange, and Catherine Eysseric

Subjects
Autocatalysis, Nuclear reprocessing, chemistry.chemical_compound, Aqueous solution, Ozone, Chemistry, Inorganic chemistry, Oxidizing agent, chemistry.chemical_element, Oxidative phosphorylation, Physical and Theoretical Chemistry, Dissolution, Ruthenium
Abstract

SummarySeveral ruthenium species compounds are typically encountered in waste management from nuclear fuel reprocessing operations. Ozone acting as a strong oxidizing agent in aqueous alkaline medium has some advantages for dissolving solid ruthenium deposits formed in process equipments, without generating troublesome by-products or secondary waste. This study is focused on oxidative dissolution of ruthenium(IV) oxyhydroxyde deposited on 304L stainless steel by ozone in alkaline medium. Oxidative dissolution of these deposits under various experimental conditions shows an analogous behaviour to that observed in a previous study with RuO2·xH2O suspensions, notably the autocatalytic effect of ruthenate ions RuO42−for the oxidative dissolution of ruthenium deposits.

Published
2008
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