Examinando por Autor "Del Toro Iniesta, J. C."

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Detailed design of the imaging magnetograph experiment (IMaX): a visible imager magnetograph for the Sunrise mission
(SPIE Astronomical Telescopes Instrumentation, 2006-07-07) Álvarez Herrero, A.; Belenguer, T.; Pastor, C.; González, L.; López Heredero, R.; Ramos, G.; Reina, M.; Sánchez, A.; Villanueva, J.; Sabau, L.; Martínez Pillet, V.; Bonet, J. A.; Collados, M.; Jochum, L.; Ballesteros, E.; Medina Trujillo, J. L.; Ruiz, C. B.; González, J. C.; Del Toro Iniesta, J. C.; López Jiménez, A. C.; Castillo Lorenzo, J.; Herranz, M.; Jerónimo, J. M.; Mellado, P.; Morales, R.; Rodríguez, J.; Domingo, V.; Gasent, J. L.; Rodríguez, P.; 0000-0003-0248-2771; 0000-0001-9228-3412; 0000-0003-4343-6632; 0000-0002-6297-0681; 0000-0002-3387-026X; 0000-0002-2197-8388; 0000-0002-6210-9648; 0000-0002-4944-5823; 0000-0001-7764-6895; 0000-0003-1661-0594; 0000-0001-9631-9558; 0000-0002-1225-4177
In this work, it is described the Imaging Magnetograph eXperiment, IMaX, one of the three postfocal instruments of the Sunrise mission. The Sunrise project consists on a stratospheric balloon with a 1 m aperture telescope, which will fly from the Antarctica within the NASA Long Duration Balloon Program. IMaX will provide vector magnetograms of the solar surface with a spatial resolution of 70 m. This data is relevant for understanding how the magnetic fields emerge in the solar surface, how they couple the photospheric base with the million degrees of temperature of the solar corona and which are the processes that are responsible of the generation of such an immense temperatures. To meet this goal IMaX should work as a high sensitivity polarimeter, high resolution spectrometer and a near diffraction limited imager. Liquid Crystal Variable Retarders will be used as polarization modulators taking advantage of the optical retardation induced by application of low electric fields and avoiding mechanical mechanisms. Therefore, the interest of these devices for aerospace applications is envisaged. The spectral resolution required will be achieved by using a LiNbO3 Fabry-Perot etalon in double pass configuration as spectral filter before the two CCDs detectors. As well phase-diversity techniques will be implemented in order to improve the image quality. Nowadays, IMaX project is in the detailed design phase before fabrication, integration, assembly and verification. This paper briefly describes the current status of the instrument and the technical solutions developed to fulfil the scientific requirements.
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Imaging polarimeters based on liquid crystal variable retarders: an emergent technology for space instrumentation
(SPIE Optical Engineering Applications, 2011-09-09) Álvarez Herrero, A.; Uribe Patarroyo, N.; García Parejo, P.; Vargas, J.; López Heredero, R.; Restrepo, R.; Martínez Pillet, V.; Del Toro Iniesta, J. C.; López, A.; Fineschi, S.; Capobianco, G.; Georges, M.; López, M.; Boer, G.; Manolis, I.; López Heredero, R. [0000-0002-2197-8388]; Vargas, J. [0000-0001-7519-6106]; García Parejo, P. [0000-0003-1556-9411]; López Jiménez, A. [0000-0002-6297-0681]; Del Toro Iniesta, J. A. [0000-0002-3387-026X]; Álvarez Herrero, A. [0000-0001-9228-3412]; Capobianco, G. [0000-0003-0520-2528]; Restrepo Gómez, R. [0000-0002-3874-3032]; Georges, M. [0000-0002-0460-3912]; Martínez Pillet, V. [0000-0001-7764-6895]
The use of Liquid Crystal Variable Retarders (LCVRs) as polarization modulators are envisaged as a promising novel technique for space instrumentation due to the inherent advantage of eliminating the need for conventional rotary polarizing optics hence the need of mechanisms. LCVRs is a mature technology for ground applications; they are wellknow, already used in polarimeters, and during the last ten years have undergone an important development, driven by the fast expansion of commercial Liquid Crystal Displays. In this work a brief review of the state of the art of imaging polarimeters based on LCVRs is presented. All of them are ground instruments, except the solar magnetograph IMaX which flew in 2009 onboard of a stratospheric balloon as part of the SUNRISE mission payload, since we have no knowledge about other spaceborne polarimeters using liquid crystal up to now. Also the main results of the activity, which was recently completed, with the objective to validate the LCVRs technology for the Solar Orbiter space mission are described. In the aforementioned mission, LCVRs will be utilized in the polarisation modulation package of the instruments SO/PHI (Polarimetric and Helioseismic Imager for Solar Orbiter) and METIS/COR (Multi Element Telescope for Imaging and Spectroscopy, Coronagraph).
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IMaX: a polarimeter based on Liquid Crystal Variable Retarders for an aerospace mission
(Wiley Online Library, 2008-05-08) Uribe Patarroyo, N.; Álvarez Herrero, A.; López Heredero, R.; Del Toro Iniesta, J. C.; López Jiménez, A. C.; Domingo, V.; Gasent, J. L.; Jochum, L.; Martínez Pillet, V.; Del Toro Iniesta, J. C. [0000-0002-3387-026X]; López Jiménez, A. [0000-0002-6297-0681]; López Heredero, R. [0000-0002-2197-8388]; Álvarez Herrero, A. [0000-0001-9228-3412]; Gasenta Blesa, J. L. [0000-0002-1225-4177]; Martínez Pillet, V. [0000-0001-7764-6895]
IMaX is the Imaging Magnetograph eXperiment, an instrument part of the payload of SUNRISE, a stratospheric balloon mission in Antarctica. It is also the precursor of the Visible Imaging Magnetograph of the future ESA Solar Orbiter mission. It is essentially a diffraction-limited imager that carries out spectropolarimetric measurements of high resolution (bandwidth of < 100 mÅ at 525.02 nm), and relates the polarimetric properties of the incoming light through a telescope with magnetic fields in the Sun, via the Zeeman effect. At the core of the instrument there are the polarization modulation components, two Liquid Crystal Variable Retarders (LCVRs). A demodulation efficiency is defined and used as the figure of merit, and it serves to find the theoretical optimum states for the LCVRs as well as to judge the quality of the pre-flight calibration of the system. This calibration and the method used to optimize the actual efficiency is explained. Also, the space qualification of the LCVRs is presented, where ellipsometry played a major role in studying the effects of radiation, vacuum and temperature in the operation of the LCVRs. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
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Space-qualified liquid-crystal variable retarders for wide-field-of-view coronagraphs
(SPIE Optical Engineering Applications, 2011-10-06) Uribe Patarroyo, N.; Álvarez Herrero, A.; García Parejo, P.; Vargas, J.; Heredero, R. L.; Restrepo, R.; Martínez Pillet, V.; Del Toro Iniesta, J. C.; López, A.; Fineschi, S.; Capobianco, G.; Georges, M.; López, M.; Boer, G.; Manolis, I.; Álvarez Herrero, A. [0000-0001-9228-3412]; Del Toro Iniesta, J. C. [0000-0002-3387-026X]; López Heredero, R. [0000-0002-2197-8388]; Vargas, J. [0000-0001-7519-6106]; López Jiménez, A. [0000-0002-6297-0681]; García Parejo, P. [0000-0003-1556-9411]; Capobianco, G. [0000-0003-0520-2528]; Georges, M. [0000-0002-0460-3912]; Restrepo Gómez, R. [0000-0002-3874-3032]; Martínez Pillet, V. [0000-0001-7764-6895]
Liquid-crystal variable retarders (LCVRs) are an emergent technology for space-based polarimeters, following its success as polarization modulators in ground-based polarimeters and ellipsometers. Wide-field double nematic LCVRs address the high angular sensitivity of nematic LCVRs at some voltage regimes. We present a work in which wide-field LCVRs were designed and built, which are suitable for wide-field-of-view instruments such as polarimetric coronagraphs. A detailed model of their angular acceptance was made, and we validated this technology for space environmental conditions, including a campaign studying the effects of gamma, proton irradiation, vibration and shock, thermo-vacuum and ultraviolet radiation.
Acceso Abierto
The Imaging Magnetograph eXperiment (IMaX) for the Sunrise Balloon-Borne Solar Observatory
(Springer Link, 2011-01-17) Martínez Pillet, V.; Del Toro Iniesta, J. C.; Álvarez Herrero, A.; Domingo, V.; Bonet, J. A.; González Fernández, C.; López Jiménez, A.; Pastor, C.; Gasent Blesa, J. L.; Mellado, P.; Piqueras, J.; Aparicio, B.; Balaguer, M.; Ballesteros, E.; Belenguer, T.; Bellot Rubio, L. R.; Berkefeld, T.; Collados, M.; Deutsch, W.; Feller, A.; Girela, F.; Grauf, B.; Heredero, R. L.; Herranz, M.; Jerónimo, J. M.; Laguna, H.; Meller, R.; Menéndez, M.; Morales, R.; Orozco Suárez, D.; Ramos, G.; Reina, M.; Ramos, J. L.; Rodríguez, P.; Sánchez, A.; Uribe Patarroyo, N.; Barthol, P.; Gandorfer, A.; Knoelker, M.; Schmidt, W.; Solanki, S. K.; Vargas Domínguez, S.; Ministerio de Ciencia e Innovación (MICINN); Deutsches Zentrum für Luft- und Raumfahrt (DLR); National Aeronautics and Space Administration (NASA); López Heredero, R. [0000-0002-2197-8388]; López Jiménez, A. [0000-0002-6297-0681]; Balaguer, M. [0000-0003-4738-7727]; Del Toro Iniesta, J. C. [0000-0002-3387-026X]; Reina Aranda, M. [0000-0003-0248-2771]; Álvarez Herrero, A. [0000-0001-9228-3412]; Herranz de la Revilla, M. L. [0000-0003-4343-6632]; Morales Muñoz, R. [0000-0003-1661-0594]; Pastor, C. [0000-0001-9631-9558]; Gasent Blesa, J. L. [0000-0002-1225-4177]; Collados, M. [0000-0002-6210-9648]; Jerónimo, J. M. [0000-0002-4944-5823]; Bellot Rubio, L. R. [0000-0001-8669-8857]; Martínez Pillet, V. [0000-0001-7764-6895]
The Imaging Magnetograph eXperiment (IMaX) is a spectropolarimeter built by four institutions in Spain that flew on board the Sunrise balloon-borne solar observatory in June 2009 for almost six days over the Arctic Circle. As a polarimeter, IMaX uses fast polarization modulation (based on the use of two liquid crystal retarders), real-time image accumulation, and dual-beam polarimetry to reach polarization sensitivities of 0.1%. As a spectrograph, the instrument uses a LiNbO3 etalon in double pass and a narrow band pre-filter to achieve a spectral resolution of 85 mÅ. IMaX uses the high-Zeeman-sensitive line of Fe I at 5250.2 Å and observes all four Stokes parameters at various points inside the spectral line. This allows vector magnetograms, Dopplergrams, and intensity frames to be produced that, after reconstruction, reach spatial resolutions in the 0.15 – 0.18 arcsec range over a 50×50 arcsec field of view. Time cadences vary between 10 and 33 s, although the shortest one only includes longitudinal polarimetry. The spectral line is sampled in various ways depending on the applied observing mode, from just two points inside the line to 11 of them. All observing modes include one extra wavelength point in the nearby continuum. Gauss equivalent sensitivities are 4 G for longitudinal fields and 80 G for transverse fields per wavelength sample. The line-of-sight velocities are estimated with statistical errors of the order of 5 – 40 m s−1. The design, calibration, and integration phases of the instrument, together with the implemented data reduction scheme, are described in some detail.
Restringido
The imaging magnetograph eXperiment for the SUNRISE balloon Antarctica project
(SPIE Astronomical Telescopes Instrumentation, 2004-10-12) Martínez Pillet, V.; Bonet, J. A.; Collados, M. V.; Jochum, L.; Mathew, S.; Medina Trujillo, J. L.; Ruiz Cobo, B.; Del Toro Iniesta, J. C.; López Jiménez, A. C.; Castillo Lorenzo, J.; Herranz, M.; Jerónimo, J. M.; Mellado, P.; Morales, R.; Rodríguez, J.; Álvarez Herrero, A.; Belenguer, T.; López Heredero, R.; Menéndez, M.; Ramos, G.; Reina, M.; Pastor, C.; Sánchez, A.; Villanueva, J.; Domingo, V.; Gasent, J. L.; Rodríguez, P.; López Heredero, R. [0000-0002-2197-8388]; López Jiménez, A. [0000-0002-6297-0681]; Reina, M. [0000-0003-0248-2771]; Del Toro Iniesta, J. C. [0000-0002-3387-026X]; Álvarez Herrero, A. [0000-0001-9228-3412]; De la Revilla, M. L. [0000-0003-4343-6632]; Callados, M. [0000-0002-6210-9648]; Morales Muñoz, R. [0000-0003-1661-0594]; Rodríguez Gómez, J. [0000-0002-6757-5912]; Ruiz Cobo, B. [0000-0001-9550-6749]; Gasent Blesa, J. L. [0000-0002-1225-4177]; Jerónimo, J. M. [0000-0002-4944-5823]; Pastor, C. [0000-0001-9631-9558]
The SUNRISE balloon project is a high-resolution mission to study solar magnetic fields able to resolve the critical scale of 100 km in the solar photosphere, or about one photon mean free path. The Imaging Magnetograph eXperiment (IMaX) is one of the three instruments that will fly in the balloon and will receive light from the 1m aperture telescope of the mission. IMaX should take advantage of the 15 days of uninterrupted solar observations and the exceptional resolution to help clarifying our understanding of the small-scale magnetic concentrations that pervade the solar surface. For this, IMaX should act as a diffraction limited imager able to carry out spectroscopic analysis with resolutions in the 50.000-100.000 range and capable to perform polarization measurements. The solutions adopted by the project to achieve all these three demanding goals are explained in this article. They include the use of Liquid Crystal Variable Retarders for the polarization modulation, one LiNbO3 etalon in double pass and two modern CCD detectors that allow for the application of phase diversity techniques by slightly changing the focus of one of the CCDs.