The Polarimetric and Helioseismic Imager on Solar Orbiter
Abstract
This paper describes the Polarimetric and Helioseismic Imager on the Solar Orbiter mission (SO/PHI), the first magnetograph and helioseismology instrument to observe the Sun from outside the Sun-Earth line. It is the key instrument meant to address the top-level science question: How does the solar dynamo work and drive connections between the Sun and the heliosphere? SO/PHI will also play an important role in answering the other top-level science questions of Solar Orbiter, as well as hosting the potential of a rich return in further science. SO/PHI measures the Zeeman effect and the Doppler shift in the FeI 617.3nm spectral line. To this end, the instrument carries out narrow-band imaging spectro-polarimetry using a tunable LiNbO_3 Fabry-Perot etalon, while the polarisation modulation is done with liquid crystal variable retarders (LCVRs). The line and the nearby continuum are sampled at six wavelength points and the data are recorded by a 2kx2k CMOS detector. To save valuable telemetry, the raw data are reduced on board, including being inverted under the assumption of a Milne-Eddington atmosphere, although simpler reduction methods are also available on board. SO/PHI is composed of two telescopes; one, the Full Disc Telescope (FDT), covers the full solar disc at all phases of the orbit, while the other, the High Resolution Telescope (HRT), can resolve structures as small as 200km on the Sun at closest perihelion. The high heat load generated through proximity to the Sun is greatly reduced by the multilayer-coated entrance windows to the two telescopes that allow less than 4% of the total sunlight to enter the instrument, most of it in a narrow wavelength band around the chosen spectral line.
Keywords
Cite
@article{arxiv.1903.11061,
title = {The Polarimetric and Helioseismic Imager on Solar Orbiter},
author = {S. K. Solanki and J. C. del Toro Iniesta and J. Woch and A. Gandorfer and J. Hirzberger and A. Alvarez-Herrero and T. Appourchaux and V. Martínez Pillet and I. Pérez-Grande and E. Sanchis Kilders and W. Schmidt and J. M. Gómez Cama and H. Michalik and W. Deutsch and G. Fernandez-Rico and B. Grauf and L. Gizon and K. Heerlein and M. Kolleck and A. Lagg and R. Meller and R. Müller and U. Schühle and J. Staub and K. Albert and M. Alvarez Copano and U. Beckmann and J. Bischoff and D. Busse and R. Enge and S. Frahm and D. Germerott and L. Guerrero and B. Löptien and T. Meierdierks and D. Oberdorfer and I. Papagiannaki and S. Ramanath and J. Schou and S. Werner and D. Yang and A. Zerr and M. Bergmann and J. Bochmann and J. Heinrichs and S. Meyer and M. Monecke and M. -F. Müller and M. Sperling and D. Álvarez Garcí a and B. Aparicio and M. Balaguer Jiménez and L. R. Bellot Rubio and J. P. Cobos Carracosa and F. Girela and D. Hernández Expósito and M. Herranz and P. Labrousse and A. López Jiménez and D. Orozco Suárez and J. L. Ramos and J. Barandiarán and L. Bastide and C. Campuzano and M. Cebollero and B. Dávila and A. Fernández-Medina and P. García Parejo and D. Garranzo-García and H. Laguna and J. A. Martín and R. Navarro and A. Núñez Peral and M. Royo and A. Sánchez and M. Silva-López and I. Vera and J. Villanueva and J. -J. Fourmond and C. Ruiz de Galarreta and M. Bouzit and V. Hervier and J. C. Le Clec'h and N. Szwec and M. Chaigneau and V. Buttice and C. Dominguez-Tagle and A. Philippon and P. Boumier and R. Le Cocguen and G. Baranjuk and A. Bell and Th. Berkefeld and J. Baumgartner and F. Heidecke and T. Maue and E. Nakai and T. Scheiffelen and M. Sigwarth and D. Soltau and R. Volkmer and J. Blanco Rodríguez and V. Domingo and A. Ferreres Sabater and J. L. Gasent Blesa and P. Rodríguez Martínez and D. Osorno Caudel and J. Bosch and A. Casas and M. Carmona and A. Herms and D. Roma and G. Alonso and A. G\' omez-Sanjuan and J. Piqueras and I. Torralbo and B. Fiethe and Y. Guan and T. Lange and H. Michel and J. A. Bonet and S. Fahmy and D. Müller and I. Zouganelis},
journal= {arXiv preprint arXiv:1903.11061},
year = {2020}
}
Comments
36 pages, 41 figures