Examinando por Autor "Ramos, G."

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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.
Restringido
Liquid-crystal variable retarders for aerospace polarimetry applications
(OSA (The Optical Society) Publishing, 2007-01-25) López Heredero, R.; Uribe Patarroyo, N.; Belenguer, T.; Ramos, G.; Sánchez, A.; Reina, M.; Martínez Pillet, V.; Álvarez Herrero, A.; Álvarez Herrero, A. [0000-0001-9228-3412]; López Heredero, R. [0000-0002-2197-8388]; Martínez Pillet, V. [0000-0001-7764-6895]
We present the optical effects of different tests that simulate the aerospace environment on the liquid-crystal variable retarders (LCVRs) used in the Imaging Magnetograph eXperiment postfocal instrument of the SUNRISE payload within the NASA Long Duration Balloon program. Analysis of the influence of vacuum, temperature, vibration, and gamma and ultraviolet radiation is performed by measuring the effects of these tests on the optical retardance, the response time, the wavefront distortion, and the transmittance, including some in situ measurements. Outgassing measurements of the different parts of the LCVRs are also shown. From the results obtained it can be concluded that these optical devices are suitable and seem to be excellent candidates for aerospace platforms.
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Lithium niobate Fabry-Perot etalons in double-pass configuration for spectral filtering in the visible imager magnetograph IMaX for the SUNRISE mission
(SPIE Astronomical Telescopes Instrumentation, 2006-06-14) Álvarez Herrero, A.; Belenguer, T.; Pastor, C.; López Heredero, R.; Ramos, G.; Martínez Pillet, V.; Bonet Navarro, J. A.; López Heredero, R. [0000-0002-2197-8388]; Álvarez Herrero, A. [0000-0001-9228-3412]; Martínez Pillet, V. [0000-0001-7764-6895]; Pastor, C. [0000-0001-9631-9558]
The Imaging MAgnetograph eXperiment, IMaX, is one of the three postfocal instruments of the Sunrise mission. The Sunrise project consists of a stratospheric balloon with a 1 m aperture telescope, which will fly from the Antarctica within the NASA Long Duration Balloon Program. IMaX should work as a diffraction limited imager and it should be capable to carry out polarization measurements and spectroscopic analysis with high resolution (50.000-100.000 range). The spectral resolution required will be achieved by using a LiNbO3 (z-cut) Fabry-Perot etalon in double pass configuration as spectral filter. Up to our knowledge, few works in the literature describe the associated problems of using these devices in an imager instrument (roughness, off-normal incidence, polarization sensitivity...). Because of that, an extensive and detailed analysis of etalon has been carried out. Special attention has been taken in order to determine the wavefront transmission error produced by the imperfections of a real etalon in double pass configuration working in collimated beam. Different theoretical models, numeric simulations and experimental data are analysed and compared obtaining a complete description of the etalon response.
Restringido
RLS iOH: ExoMars Raman laser spectrometer optical head bread board to flight model design and performance evolutions
(Wiley Analytical Science, 2020-09-01) Ramos, G.; Sanz Palomino, M.; Moral, A.; Pérez, C.; Belenguer, T.; Canchal, R.; Prieto, J. A. R.; Santiago, A.; Gordillo, C.; Escribano, D.; López Reyes, G.; Rull, F.; Ministerio de Economía y Competitividad (MINECO); López Reyes, G. [0000-0003-1005-1760]; Moral, A. G. [0000-0002-6190-8560]; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Raman Laser Spectrometer (RLS) is the Pasteur Payload instrument of the ExoMars mission that will perform Raman spectroscopy for the first time in a planetary space mission. RLS main units are: SPU (SPectrometer Unit), iOH (internal Optical Head), and ICEU (Instrument Control and Excitation Unit), that includes the laser for samples excitation purposes. The iOH focuses the excitation laser into the crushed samples (located at the ALD, Analytical Laboratory Drawer, carrousel) through the excitation path, and collects the Raman emission from the sample (collection path). Its original design presented a high laser trace reaching to the SPU detector, and although a certain level was required for instrument calibration, the found level was expected to be capable of degrading the acquired spectra confounding some Raman peaks. So, the iOH optical and opto‐mechanical designs were needed to be updated from the BB (Bread Board) to the engineering and qualification model (iOH EQM), in order to fix the desired amount of laser trace, and after the fabrication and the commitment of the commercial elements, the assembly and integration verification (AIV) process was carried out. Considering the results obtained during the EQM integration verification and the first functional tests, the RLS calibration target (CT) emission analysis, additional changes were found to be required for the Flight Model, FM. In this paper, the RLS iOH designs and functional tests evolutions for the different models are summarized, focusing on the iOH AIV process and emphasizing on the iOH performance evaluation (by using CT spectra) from the re‐design activities.
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.