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Toshifumi Shimizu (ISAS/JAXA)

Model instruments baseline specification and key open issues EUV/FUV High-Throughput Spectroscopic Telescope. 4 th Solar-C Science Definition Meeting At St. Andrews, U.K. Toshifumi Shimizu (ISAS/JAXA). EUVST’s roles in Solar-C.

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Toshifumi Shimizu (ISAS/JAXA)

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  1. Model instruments baseline specification and key open issuesEUV/FUV High-Throughput Spectroscopic Telescope 4th Solar-C Science Definition Meeting At St. Andrews, U.K. Toshifumi Shimizu (ISAS/JAXA) SCSDM-4

  2. EUVST’s roles in Solar-C • EUV~FUV spectroscopic telescope (EUVS or EUVST) is a key component for achieving Solar-C science goals. • It will provide the crucial link between the photospheric and chromospheric magnetic field and plasma characteristics obtained by the SUVIT and the high temporal and spatial resolution images of the corona provided by the XIT. • Key science requirements • Simultaneous spectroscopic measurements in emission lines sampling all temperature regions present in the solar atmosphere, i.e., Chromosphere – TR – Corona - Flare • Resolving 0.3” spatial scale to validate the structure connections among all temperature regions • Effective area an order of magnitude higher than currently available for solar studies, much improving temporal cadence. • As major European contribution to Solar-C, this telescope with naming LEMUR (Large European Module for Solar Ultraviolet Research) has been proposed to ESA as a mission of opportunity in the 2010 Cosmic Vision Call. SCSDM-4

  3. EUVST(LEMUR): instrument requirements & layout • Optics: single off-axis mirror (30cmf, f=360cm) and a grating • Telescope length: 430cm With low scattering optics, for exploring low EM regions (MR and CH). Slit assembly SCSDM-4

  4. EUVST/LEMUR SCSDM-4

  5. Temperature coverage and radiometric performances For active region plasma IRIS SiIII CIII o o o o OVI SiII HI NeVIII FeiX Mg X FeXI FeXII o o FeXVIII o OIV NV, OV Flare lines: Fe XVIII 974 Fe XIX 592 Fe XX 721 Fe XXI 786 Fe XXIII 1079 Fe XXIV 192 Counts/s/arcsec • Broad temperature coverage 104 K to 107 K • Performance at two temperature regions important for coronal heating studies SCSDM-4

  6. Temperature coverage 1) High temp Corona • For observing nanoflares, it is important to probe 5-10 MK plasmas with good temperature discrimination. • It is confirmed that the Fe XVIII 974.86 line (log Te~6.80) is strong and unblended. It will allows ~1s cadence observations of line radiances, profiles, and Doppler flows in hot (6 MK) plasma. • Ca XIV, XV, XVI, XVII lines (log Te =6.55-6.75) are available, but need • longer exposures. • Flare lines are available. SUMER campaign on 8 Nov 2011 (Teriaca et al. 2012) SCSDM-4 Radiometric performance after the revision (2012/1)

  7. Temperature coverage 2) High TR to Corona • To properly follow mass and energy flows in the temperature region from high TR to corona, where morphological changes are observed, a further line is needed between the strong OVI 1032 (log Te=5.50) and Ne VIII 770 (log Te=5.75), especially in active region studies. • Having the Ne VII 465 line (log Te= 5.75) becomes possible with modification of instrument design (larger detectors). SUMER – AR, nearly simultaneous OVI 1032 NeVIII 770 Intensity SCSDM-4 Doppler velocity Radiometric performance after the revision (2012/1)

  8. Determine structures and evaluate energy and mass flows from observations • Determine “dynamical” structures and their connections in ch.-TR-corona system. • Trace changes on Poynting flux as a function of space (along B & across B) and time, by observing changes on velocities (Doppler & turbulent) and density (Intensity). • It is important to identify signatures of energy dissipation, such as temporal and/or spatial damping of waves • For oscillations, frequencies, phase speeds and temporal/spatial variation of transverse displacements are measurable. Compare the properties and theoretically modeled wave modes for inferring wave mode. SCSDM-4

  9. White lines: Magnetic field lines Disk Center (C) Limb (L) Resolving 0.3” spatial scale essential to trace structure connections in atmospheres • SOT imaging obs. tells 0.3~0.4” as typical width of chromospheric spicules. • Spectroscopic measurements with EIS suggests only ~10% of volume in coronal loops (~0.3” in length) is filled with hot plasma. • Unresolved high-speed (>100km/s) jets at base of coronal loops • Unresolved dynamic events and structures CaIIH spicules on the limb A breakthrough comes from observations telling dynamical flow behaviors and plasma properties in ~0.3” structures Chromosphere (~0.3”) Corona (~1”) SCSDM-4 Chr.(CaII) 3-5min, TR(Si IV) in bursts of up to 30 min, Corona(NeVIII) more diffuse

  10. High cadence to follow physical changes Hinode/SOT Spicles • “Fast” scan observations • Effective area an order of magnitude higher than currently available instruments slit width 1” 5s (AR) – 15s (QS) for 5” width 0.28” 18s (AR) - 54s (QS) for 5” width if 1s for AR and 3 s for QS is used as exposure.  Powerful to measure properties of oscillating structures (waves). Repeated scan for 5” (DePontieu et al.2007) Observation mode examples SCSDM-4

  11. EUV/UV High-throughput Spectroscopic Telescope • One of key instruments for archiving Solar-C science goals With low scattering optics, for exploring low EM regions (MR and CH). Slit assembly SCSDM-4

  12. SCSDM-4

  13. EUVST/LEMUR

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