The involvement of PMOD/WRC in the EUI and SPICE instruments onboard the

1. The involvement of PMOD/WRC in the EUI and SPICE instruments onboard the ESA/NASA Mission Solar Orbiter Haberreiter, Margit; Schmutz, Werner; Gyo, Manfred; Büchel Valeria, Dürig Fabian; Pfiffner, Dany; in collaboration with Swiss Industry and the Solar Orbiter Team Physikalisch-MeteorologischesObservatoriumDavos and World Radiation Center (PMOD/WRC), Davos, Switzerland Margit.Haberreiter@pmodwrc.ch 2. Solar Orbiter - Overview 2. EUI and SPICE Instruments and main Science goals Solar Orbiter is an ESA/NASA mission By approaching as close as 0.28 AU, Solar Orbiter will view the Sun with high spatial resolution and combine this with in-situ measurements of the surrounding heliosphere. Thanks to its unique orbit (see Figure above, right panel), Solar Orbiter will deliver images and data of the unexplored Sun's polar regions and the side of the Sun not visible from Earth. Figure 2.The EUI (Extreme Ultraviolet Imagers is composed of two high resolution imagers (HRI), one at Lyman α and at 17,4 nm one dual band full-sun imager (FSI) working alternatively at the two 17,4 and 30,4 nm EUV pass bands. In all the units, the image is produced by a mirror-telescope, working in nearly normal incidence. Figure 3.Overview of the SPICE instrument. Spectrally resolved imaging spectroscopy allows us to understand the mechanisms responsible for flow of mass and energy through the solar atmosphere. SPICE is built on the heritage from SOHO/SUMER and CDS, Hinode/EIS. The goal is to link SPICE observations with in-situ measurements onboard Solar Orbiter . This will allow us to link processes in the solar atmosphere with the heliosphere, in particular understand the dynamics in the solar atmosphere and the processes responsible for the acceleration of the Solar Wind. Two spectral windows will be observed with a separate shortwave and longwave detector: Detector 1: 703.9 - 790.2 Å Detector 2: 972.5 - 1049.2 Å • The main science goals of Solar Orbiter are: • Determine the properties, dynamics and interactions of plasma, fields and particles in the near-Sun heliosphere • 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 magnitized atmosphere • Probe the solar dynamo by observing the Sun’s high-latitude field, flows and seismic waves The Solar Orbiter spacecraft is a Sun-pointed, 3-axis stabilized platform, with a dedicated heat shield to provide protection from the high levels of solar flux near perihelion. Feed-throughs in the heat shield (with individual doors) provide the remote-sensing instruments with their required fields-of-view to the Sun. Single-sided solar arrays provide the required power throughout the mission over the wide range of distances from the Sun and can be rotated about their longitudinal axis to manage the array temperature, particularly important during closest approach to the Sun. 3. Components for SPICE and EUI built and managed by PMOD Danys Low Voltage Power Supply Figure 2. Upper panel: The SPICE Door Mechanisms (SDM)resides at the entrance of the SPICE instrument. It contains a movable shutter paddle to provide contamination control during ground and launch activities. When the shutter is closed, it forms a labyrinth seal to form a purgeable instrument cavity for contamination protection during AIT and launch. Left panel:The off-axis parabola mirror forms an image of the sun onto the entrance slit assembly containing four interchangeable slits of differing widths. The slit selects a portion of the solar image and passes it to a concave TVLS grating which re-images the spectrally dispersed radiation onto two array detectors.Each slit is fabricated on a single crystal Silicon wafer using precision lithography techniques developed for electronic chips Right upper panel:LVPS Right lower panel: EUI optical bench structure. 4. Science Observations with SPICE and EUI Table 1: Key spectral lines as to be observed by SPICE: References: Haberretier, M. 2011, Solar EUV Spectrum Calculated for Quiet Sun Conditions, Solar Physics, 274, 473. Haberreiter, M. 2012, Towards the reconstruction of the EUV irradiance for solar Cycle 23. In: Proceedings of the International Astronomical Union, IAU Symposium, Volume 286, p. 97-100. Synthetic Spectra as calculated with the SOLMOD code (Haberreiter 2011, 2012) showing the spectral ranges at which EUI (left panel) and SPICE will observe. EUI will take images in the EUV at 17.1 nm and 30.4 nm observing the strong Fe XII 17.1nm and He II 30.4 nm,. SPICE will observe in two spectral intervals, between 703.9 - 790.2 Å and 972.5 - 1049.2 Å, indicated on the right hand panel.