2.7.0 spase://ESA/Instrument/SolarOrbiter/PHI Polarimetric and Helioseismic Imager (PHI) 2024-12-23T00:08:46 2024-12-23T00:08:46 Metadata created by SY 2025-05-02T00:08:46 Updated the Contact The Polarimetric and Helioseismic Imager (PHI) is a solar polarimeter and magnetograph designed to measure the vector magnetic field and line-of-sight velocity in the solar photosphere. The science objectives for PHI are to: investigate the links between the solar surface, corona, and inner heliosphere; explore, at all latitudes, the energetics, dynamics and fine-scale structure of the Sun’s magnetized atmosphere; and probe the solar dynamo by observing the Sun’s high-latitude field, flows and seismic waves. PHI is a diffraction limited, wavelength tunable, quasi-monochromatic, polarization sensitive imager with two telescopes; a High Resolution Telescope (HRT) and a Full-Disc Telescope (FDT) which alternatively feed a common filtergraph and a 2048 x 2048 pixel focal plane array. The working wavelength is 617.3 nm (Fe spectral line). The instrument is mounted behind the sunshield, with heat-rejecting entrance window apertures for the telescopes. It is made of an aluminum-beryllium alloy and low-expansion carbon-fiber reinforced plastic. The HRT is a decentered Ritchey-Chretien design with a 140mm diameter pupil. It has a field-of-view of 0.28 x 0.28 degrees and a spatial resolution of about 200 km at closest perihelion. The FDT has an entrance pupil diameter of 17.5 mm and an effective focal length of 579 mm. The field-of-view is 2 degrees, resolution at 0.28 AU is 725 km/pixel. The filtergraph consists of a lithium niobide (LiNbO3) solid-state etalon which can change refractive index as a function of voltage and select passbands of order 100 milliangstroms wide. A Polarization Modulation Package performs polarimetric analysis for each telescope. It comprises two nematic liquid crystal retarders and a linear polarizer analyzer. For more detailed information on PHI, see: https://doi.org/10.1051/0004-6361/201935325 Solar Orbiter is a mission of international cooperation between the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA), operated by ESA. spase://SMWG/Person/Sami.K.Solanki PrincipalInvestigator spase://SMWG/Person/Joachim.Woch GeneralContact spase://SMWG/Person/Gherardo.Valori CoPI NASA NSSDCA Master Catalog https://nssdc.gsfc.nasa.gov/nmc/experiment/display.action?id=2020-010A-03 NSSDCA Master Catalog Listing for the Solar Orbiter PHI The Solar Orbiter PHI Website https://www.mps.mpg.de/solar-physics/solar-orbiter-phi The PHI instrument paper https://doi.org/10.1051/0004-6361/201935325 Imager Polarimetric and Helioseismic Imager (PHI) 2020-02-10T04:03:00 The start date and time listed here correspond to when Solar Orbiter was launched spase://ESA/Observatory/SolarOrbiter