Examinando por Autor "Bonet, J. A."

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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.
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.