Tony Pamplona

Euclid near-infrared spectrophotometer instrument concept at the end of the phase A study

The Euclid mission objective is to map the geometry of the dark Universe by investigating the distance-redshift relationship and the evolution of cosmic structures. The NISP (Near Infrared Spectro-Photometer) is one of the two Euclid instruments operating in the near-IR spectral region (0.9-2μm). The instrument is composed of: - a cold (140K) optomechanical subsystem constituted by a SiC structure, an optical assembly, a filter wheel mechanism, a grism wheel mechanism, a calibration unit and a thermal control - a detection subsystem based on a mosaic of 16 Teledyne HAWAII2RG 2.4μm. The detection subsystem is mounted on the optomechanical subsystem structure - a warm electronic subsystem (280K) composed of a data processing / detector control unit and of an instrument control unit. This presentation will describe the architecture of the instrument, the expected performance and the technological key challenges. This paper is presented on behalf of the Euclid Consortium.

Three bipods slicer prototype: tests and finite element calculations

For integral field spectroscopy R&D activities in progress at LAM, and particularly in relation with SNAP - SuperNova/Acceleration Probe - spectrograph, LAM has an on-going program to qualify Image Slicers for space instrumentation. In this context, an optomechanical concept of an image slicer supported by three bipods has been designed, realized and tested at the laboratory. This paper presents the mechanical design of the invar mount equipped with three bipods and supporting an assembly of 60 thin zerodur slices tied together thanks to optical contact. We document the design improvement made from last blades flexures prototype and we describe all the tests conducted on this new prototype: optical contact tests, vibration tests and thermal cycles. Thanks to a detailed FEM analysis on this three bipods concept, we correlate simulations with tests.

An integral field spectrograph for SNAP

A well-adapted spectrograph concept has been developed for the SNAP (SuperNova/Acceleration Probe) experiment. The goal is to ensure proper identification of Type Iz supernovae and to standardize the magnitude of each candidate by determining explosion parameters. The spectrograph is also a key element for the calibration of the science mission. An instrument based on an integral field method with the powerful concept of imager slicing has been designed and is presented in this paper. The spectrograph concept is optimized to have high efficiency and low spectral resolution (R~100), constant through the wavelength range (0.35-1.7μm), adapted to the scientific goals of the mission.

Silicon carbide main structure for EUCLID NISP instrument in final development

In the scope of EUCLID spatial mission, NISP instrument requires high positioning accuracy and high dimensional stability to achieve the required optical performances. LAM is in charge of the development of the instrument main structure which is based on silicon carbide material technology and allows the accurate positioning and maintain of the optomechanical concept sub-systems. This article presents the main steps of this development. It describes the challenging design of this mechanical concept. The associated finite element model, demonstrating the thermomechanical strength of the structure, is presented. Spatial environment vibrations tests performed on the hardware are explained and detailed: requirements, instrumentation and test methodology with the introduction of notching. Finally, the correlation study between finite element analyses and tests is exposed.

The SiC structure of the EUCLID NISP instrument

Euclid is a part of the European Space Agency Cosmic Vision program. Euclid mission’s goal is to understand the origin of the accelerating expansion of the Universe. This space mission will embark a 1.2 m Korsch telescope, a visible imager (VIS) and a near-infrared spectrometer and photometer (NISP).

Euclid near infrared spectrophotometer instrument concept and first test results at the end of phase B or the GRAVITY beam combiner instrument at the VLTI

The Euclid mission objective is to understand why the expansion of the Universe is accelerating by mapping the geometry of the dark Universe by investigating the distance-redshift relationship and tracing the evolution of cosmic structures. The Euclid project is part of ESAs Cosmic Vision program with its launch planned for 2020. The NISP (Near Infrared Spectro-Photometer) is one of the two Euclid instruments and is operating in the near-IR spectral region (0.9-2μm) as a photometer and spectrometer. The instrument is composed of: - a cold (135K) optomechanical subsystem consisting of a SiC structure, an optical assembly (corrector and camera lens), a filter wheel mechanism, a grism wheel mechanism, a calibration unit and a thermal control system - a detection subsystem based on a mosaic of 16 Teledyne HAWAII2RG cooled to 95K with their front-end readout electronic cooled to 140K, integrated on a mechanical focal plane structure made with Molybdenum and Aluminum. The detection subsystem is mounted on the optomechanical subsystem structure - a warm electronic subsystem (280K) composed of a data processing / detector control unit and of an instrument control unit that interfaces with the spacecraft via a 1553 bus for command and control and via Spacewire links for science data This presentation describes the architecture of the instrument at the end of the phase B (Preliminary Design Review), the expected performance, the technological key challenges and preliminary test results obtained on a detection system demonstration model.

Euclid near infrared spectrophotometer instrument concept and first test results at the end of phase B

The Euclid mission objective is to understand why the expansion of the Universe is accelerating by mapping the geometry of the dark Universe by investigating the distance-redshift relationship and tracing the evolution of cosmic structures. The Euclid project is part of ESAs Cosmic Vision program with its launch planned for 2020. The NISP (Near Infrared Spectro-Photometer) is one of the two Euclid instruments and is operating in the near-IR spectral region (0.9-2μm) as a photometer and spectrometer. The instrument is composed of: - a cold (135K) optomechanical subsystem consisting of a SiC structure, an optical assembly (corrector and camera lens), a filter wheel mechanism, a grism wheel mechanism, a calibration unit and a thermal control system - a detection subsystem based on a mosaic of 16 Teledyne HAWAII2RG cooled to 95K with their front-end readout electronic cooled to 140K, integrated on a mechanical focal plane structure made with Molybdenum and Aluminum. The detection subsystem is mounted on the optomechanical subsystem structure - a warm electronic subsystem (280K) composed of a data processing / detector control unit and of an instrument control unit that interfaces with the spacecraft via a 1553 bus for command and control and via Spacewire links for science data This presentation describes the architecture of the instrument at the end of the phase B (Preliminary Design Review), the expected performance, the technological key challenges and preliminary test results obtained on a detection system demonstration model.

Opto-mechanical Design of a DMD Multislit Spectrograph for the ESA Euclid Mission

The Euclid mission proposed in the context of the ESA Cosmic Vision program is aimed to study the challenging problem of the Dark Energy, responsible of the acceleration of the Universe. One of the three probes of Euclid is dedicated to study the Baryonic Acoustic Oscillations by means of spectroscopic observations of millions of galaxies in the Near Infrared. One option for the Euclid Near Infrared Spectrograph (ENIS) is a multi-slit approach based on Digital Micromirror Device (DMD) used as reconfigurable slit mask. The Texas Instrument 2048*1080 DMD with 13.68 micrometers pitch has been chosen. ENIS optical design is composed of four arms each using one DMD to cover a total FOV of 0.48 square degree. The fore-optic design has to cope with the difficult task of having simultaneously a fast beam (F/2.7) and a quasi-diffraction limited image on a 24 deg tilted plane. The compact three mirrors spectrograph is using a grism in convergent beam for simplicity and compactness purposes. From the optical design, the mechanical structure is based on a common carbon honeycomb bench to reach the challenging requirements of volume and mass.