This will count as one of your downloads.
You will have access to both the presentation and article (if available).
The development of the alignment techniques for small instruments is well validated throughout the history of the Optomechanical and astronomical instrumentation, nevertheless those techniques cannot be applied on large ones. This thesis proposes a procedure that allows to evaluate the position of optical elements in large volume very precisely. This enables the achievement of the scientific goals by minimizing the alignment procedure duration the costs.
In this work it is evaluated the possibility to use a laser tracker as essential embedded tool for the alignment and for the monitoring of the instrument, or better, evaluate if the uncertainty of the tracker measuring the optical elements stay within the alignment requirements.
The case study presented here is MORFEO which is a first-light instrument for the European Extremely Large Telescope. The study consists in the realization of a software that optimizes the position of the tracker inside the instrument considering the nominal position of the targets measured (SMRs) and the possible vignetting based on the prediction of the accuracy and repeatability of the measurements. This analysis is made by steps: the first one considers the error model gave from the manufacture of the tracker. The second one is based on a series of tests and characterizations performed in laboratory to determine more accurately the performances. The results obtained have been validated using a dummy version of an optomechanical element measured by using a Coordinate Measurement Machine (CMM).
In this paper we present the status of the Thermal Control System (ThCS) with a focus on the thermal and cooling circuits design. The prototyping plan foreseen for the future to validate this circuit is also presented.
MORFEO (formerly known as MAORY) is an adaptive optics module able to compensate the wavefront disturbances affective the scientific observation. It will be installed on the straight-through port of the telescope Nasmyth platform to serve the first-light instrument MICADO and with the provision for a future second instrument. The module underwent the Preliminary Design Review in 2021 and is expected to be commissioned in 2029.
In this paper we present the current status of the Thermal Control System (ThCS) including the modifications required during the Preliminary Design Review. Due to the peculiar optical and mechanical design, a number of FEM and CFD analysis have been performed to verify the compliance of the system to the technical budget. The results of those analysis are then showed together with the current thermal and cooling circuits design derived from them.
The Multi-conjugate adaptive Optics Relay For ELT Observations (MORFEO), formerly MAORY, is the Multi-conjugate Adaptive Optics (MCAO) relay for the Extremely Large Telescope (ELT). The instrument provides the MCAO correction to two instruments at the ELT Nasmyth platform. One first light instrument fed by MORFEO is the Multi-AO Imaging Camera for Deep Observations (MICADO) that will provide imaging, astrometric, spectroscopic and coronographic observing modes. A second generation instrument, still to be defined, will occupy the other port of MORFEO. The delivered MCAO-corrected Field of View (FoV) of MORFEO is 2 arcmin. In this paper we present the possible fine optical alignment and recollimation strategies to bring the relay optics within the diffraction-limited performances.
More than one MORFEO fine Optical Alignment (MOA) strategy is currently under study in the development of the instrument towards its final design review. Given the complexity and the size of this new generation instrument diversifying and enlarging the set of possible techniques for the system alignment is an effective and more robust approach. As the Alignment Integration Verification (AIV) phase will develop the different strategies will be deployed and tested to possibly spot the best method (if any) among the others which will then be kept as back-up alternatives. One technique relies on the metrology of out-of-focus PSF images as proxy of the system pupil to detect the main optical aberrations in the instrument. This method has been proposed by Tokovinin & Heathcote [1] for a 2-mirror telescope. The challenge to be faced with MORFEO is given by the large number of optical elements and the related pseudo wavefront sensing limitations. Other techniques under study involve the use of wavefront sensing, phase diversity techniques and aberrations spotting using the MORFEO deformable mirrors. The MOA is meant to be performed both at the first AIV operations and at the periodic recollimations of the system during its nominal operation lifetime. The paper reports the results of a preliminary set of simulations carried out using a OpticStudio-Matlab simulator for the Donut technique.
MAORY stands for Multi-conjugate Adaptive Optics RelaY (the name has been recently changed to MORFEO, which stands for Multiconjugate adaptive Optics For ELT Observations, thus in this article we will use MORFEO), and it is one of the instruments of the European Extremely Large Telescope (ELT). The main function of MORFEO is to relay the light beam from the ELT focal plane to the client instrument (initially MICADO) while compensating, through a multiconjugate adaptive optics system, the effects of the atmospheric turbulence and other disturbances affecting the wavefronts coming from the scientific sources of interest.
The MORFEO instrument is designed and developed by a European consortium composed of INAF (Istituto Nazionale di AstroFisica, Italy), CNRS/INSU (Centre National de la Recherche Scientifique/ Institut National des Sciences de l’Univers, France), NUIG (National University of Ireland Galway, Ireland) and ESO (European Southern Observatory, Europe).
The opto-mechanical design of MORFEO has been developed in 3 dimensions, using the volume between the ELT output focal plane and the Nasmyth floor. The design uses the available volume in a very efficient way, but this poses constraints on the orientation of the optical elements and adds complexity to the AIT operations. In this paper we describe the strategy of the AIT process which will be performed at INAF-OAS Bologna (Italy), which is conceived to maximize knowledge of the instrument and thereby optimize (and, possibly, minimize) the time requested at Armazones for the AIV operations.
MORFEO/MAORY is the post-focal adaptive optics instrument of the ELT. It is designed to provide the 53×53 arcsec field of view of MICADO with MCAO correction based on split-tomography, where the Low-Order modes are sensed by three NGS-based WFS. To maximize the sky-coverage the LO-WFS are 2×2 subapertures Shack- Hartmann sensors working in the H band, making use of the FREDA detectors. MAORY also implements 3 dedicated NGS-based truth sensors to measure at slow rate the true higher order atmospheric aberrations and to de-trend the LGS WFS measurements. These WFS work with the visible light of the NGS to feed a 10 × 10 SH sensor that makes use of the ALICE detector. Each unit of LOR WFS is provided with a couple of orthogonal linear stages to allow for the NGS acquisition in a 80 arcsec radius. The 3 LOR WFS are arranged at 120° geometry on a common support structure that rigidly connects them to MICADO and its rotator.
In this paper we present the status of the LOR WFS Module at the output of the MORFEO preliminary design review. We focus on the optomechanical arrangement of the subsystem highlighting the design choices and the analyses we carried out to verify its compliance to the requirements.
MORFEO, formerly known with the acronym MAORY, is the Multi-Conjugated Adaptive Optics (MCAO) module for the European Extremely Large Telescope (ELT). MORFEO is designed to feed the Near Infrared (NIR) camera MICADO with both MCAO and Single-Conjugated AO (SCAO) operation modes. The optical configuration provides a one to one imaging of the telescope focal surface on two ports (one feeding MICADO and the other dedicated to a future instrument) and it is equipped with two post-focal deformable mirrors together with the Laser Guide Star (LGS) and Natural Guide Star (NGS) channels for wavefront sensing and tomographic reconstruction.
In this paper, we present the status of the optical configuration at the completion of the Preliminary Design Review (PDR). We will focus our attention on the tolerance analysis of the elements, consisting in both manufacturing and alignment, to provide the expected performances of the instrument after initial integration. We will also present the outcomes of the stability analysis of the instrument, consisting in rigid-body motions and thermoelastic deformations of the structure and optomechanics, used to define the procedures and benchmark to maintain the instrument performances during operation. Details on the integrated modelling, specifically developed for this purpose, will be provided.
IBIS 2.0: optical layout and polarimetric unit of the Interferometric BIdimensional Spectrometer 2.0
-
Definition of the structure with all the geometrical parameters as input for the code. Any type of initial condition (dimension and shape) can be considered starting from the kinematic chain between each part.
Definition of all the parameters required for the analysis. All the physical proprieties of the materials are defined in terms of mechanical and thermal behavior.
Definition of the proper mesh, with the selection of proper elements type, boundary conditions and applied loads.
Thanks to these three steps is possible to obtain practically any layout. Realistic survival and operational requirements of both ground and space based application has driven the analyses done. A comparison between the numerical simulations and a real example has been done to validate the modelling technique. The final result is a validated code with user’s interface, and a parametric analysis of the behavior of the optomechanical mountings based on hexapodal kinematics architecture.
View contact details
No SPIE Account? Create one
