Science Specification of SOLAR-C payload SOLAR-C Working Group 2012 July 23

SUVIT ItemDescription Telescope Aplanatic Gregorian telescope: diameter of primary: ~1.5m Focal Plane Instruments Broadband Filtergraph (BF), Narrowband Filtergraph (NF), Spectro-polarimeter (SP) Wavelength coverage 280 nm (TBD) – 1100 nm Spectral lines (spectro-polarimetry) Chromosphere: He I 1083 nm, Ca II 854 nm Dynamics: Mg II 280nm (not baseline) Photosphere: Si I nm, Fe I 525 nm Spectral lines (imaging) Chromosphere: Mg II 280nm (TBD), Ca II 854nm, H I 656nm, Na I 589nm, Mg I 517nm Photosphere: Fe I 525 nm, continuum (wavelength TBD) Sampling scale Imaging: 0.015” (narrow field), 0.045” (wide field) Spectro-polarimetry: 0.07” Spatial resolution (or imaging performance) Imaging: 0.05” at 280nm (TBD), 0.09” at 525nm, 0.14” at 854nm Spectro-polarimetry: Slit scan: 0.14”, IFU: 0.14”(along slit)×0.18” (across slit) Slit width Slit: 0.07”, IFU: effectively 0.18” Spectral resolution Narrowband filtergram: ~50,000 Spectro-polarimetry: 100,000 –210,000 (slit), ~96,000 (IFU) Exposure time Intensity observations: 0.05 – 1 sec, Polarimetric observations: 1 – 20 sec Polarimetric accuracy of chromospheric lines 1×10 -4 (6×10 -3 ) for 0.2” (0.1”) sampling and 20 (1) sec integration Sensitivity of B long : 1–2 (10-20) G, of B trans : ~100 (~300G) [Zeeman], 0.1–100 [Hanle] G Filed of view Imaging: 61×61 arcsecs (narrow field), 184×184 arcsecs (wide field) Slit scanning polarimetry: 184×143 arcsecs 2D spectro-polarimetry (IFU) : 10×10 arcsecs

SUVIT ItemScience requirementsScience backgrounds Related hardware limitations 1.5m telescope aperture -High spatial resolution <0.1” -Number of collected photons for spectro-polarimetry of chromosphere -Signature of smaller-scale photospheric/chromospheric structures in Hinode observations and recent numerical simulations -0.01% polarization measurement for chromospheric magnetic fields -Fairing size of H IIA rocket -Max size of 1.5m diameter mirror available from the mirror vendor that has Hinode heritage 0.015” (0.045”) spatial sampling in imaging observations -Diffraction limit of 1.5m telescope at 280nm: 0.047” -(FOV=184”x184”) -Highest resolution in UV range -(FOV to cover typical active regions) -Pointing stability by active controls -Optical performance and image restoration at UV Slit width -Slit scan 0.07” -IFU: 0.18” Optimized for IR observations in spatial resolution and throughput -Format of detector for target FOV -Available optical fibers for IFU Line selection (spectro-polarimetry) -He I 1083nm, Ca II 854nm -Mg II 280nm (TBD) -Fe I 525 nm (TBD) -Measurement of chromospheric magnetic fields and dynamics -Measurement of photospheric magnetic fields and dynamic -Detector sensitivity at visible and near-IR -Simultaneous observation of two wave bands not possible -Mirror coating and glass materials for sensitivity at UV Spectral resolution -Slit: 100,000 – 200,000 -IFU: 96,000 -Sufficient for both photosphere and chromosphere -IFU: sufficient for chromosphere -Detector format in association with observing spectral range and FOV -Available optical fiber for IFU Exposure duration Intensity: < 0.05–1 sec Polarimetry: 1–20 sec -High-frequency waves -0.01% photometry for B -High-speed IR camera -Limited temporal cadence or duration because of the limited telemetry amount Field of view 184×184 arcsecs Raster scan 184×143 arcsecs IFU: 10×10 arcsecs -Diffraction limit, wide field -Size of active regions -Size of chromospheric structures -Sampling unit and detector format -Optical design to accommodate large FOV.

EUVS/LEMUR ItemDescription Telescope Off-axis single mirror telescope: diameter of primary: 30 cm Focal Plane Instruments Spectrographs, Slit imaging camera for co-alignment Wavelength coverage Spectrographs: First order: 17–21 nm, 69 – 85 nm, 92.5 – nm, 111.5–127.5 nm Second order: 46–54 nm, 56–64 nm Slit imaging camera: A chromospheric line/band (e.g., continuum around 160 nm) Temperature coverage 0.01 – 20 MK Imaging performance 0.28″ in 80% encircled energy over nominal field of view (FOV) (0.14″ reachable in the range on a reduced FOV) Spatial sampling 0.14” at detector Slit 0.14″, 0.28″, 0.56″, 1″, 5″ Spectral resolution (  17,000~30,000 Exposure time 1 – 5 s for 0.28 arcsec sampling 0.1 – 0.5 s for 1 arcsec sampling Field of view 280 arcsec (along slit) × 300 arcsec (scanning direction)

EUVS/LEMUR ItemScience requirementsScience backgroundsRelated hardware limitations Telescope aperture 30 cmHigh sensitivityPrimary mirror needs a fine pointing capability (raster scanning and image stabilization) Wavelength (or line) selection Spectrographs: Fist order: 17–21 nm, 69 – 85 nm 92.5 – nm, 111.5–127.5 nm Second order: 46–54 nm, 56–64 nm Slit imaging camera: Chromospheric image with 0.3″ Spectrographs: Make measurements with spectral lines from a broad temperature range and with adequate plasma diagnostics covering the entire outer atmosphere, i.e., chromospheric, transition region, low corona and flare temperatures. Because of the required high temporal and spatial resolution, the spectral bands were defined such to include intense spectral lines in all temperature regimes. Slit imaging camera: Co-alignment with other instruments Spectrographs: nm band: CCD detector with aluminum foil filter for rejecting the visible light and with a focal plane shutter. -Other bands: Intensified CCD or APS detector (blind to visible light). Spectral resolution (λ/Δλ) 17,000 ~30,000Enhancement in velocity resolution for the unresolved velocity signature at the energy deposition sites in Hinode observations -Instrument length < spacecraft -Minimum number of reflections -Temperature coverage has higher priority than high spectral resolution. Imaging performance 0.28″ in 80% encircled energy over nominal FOV (0.14″ achievable in the nm band) Typical width of chromospheric features is ″. Coronal volume filling factor ~0.1 from Hinode observations at 2″ spatial resolution. -Instrument length -TVLS grating magnification. -Image stabilization. Exposure cadence - 1 – 5 s for 0.28″ sampling - < 1 s for 1″ sampling -Rapid heating of coronal structures-Effective area (Size of primary mirror, reflectance, grating efficiency, detector efficiency) Scanning cadence ~25 s for 14″ wide area (0.28″) ~500 s for 280″ wide area (0.58″) -Local dynamics -Dynamics in active regions -Readout speed of detector -Response time of mechanisms Field of view Spectrographs: 280″ (along slit) ×300″ (scan range) Slit imaging camera:> 200″ ×300″ Full coverage of an active region Co-alignment with other instruments -2K pixel detector along the slit -Scanning range -Image quality over FOV

XIT/GI ItemDescription Telescope Ritchey-Chretien telescope: diameter of aperture: ~30 cm Focal plane detector Back-illuminated CCD Wavelength range 9 – 34 nm (some from 9.4nm, 17.1nm, 19.5nm, 21.1nm, 30.4 nm, 33.5nm) Plate scale 0.1 arcsec/pixel sampling Spatial resolution 0.2 – 0.3 arcsec within 200 arcsec off-axis distance Exposure cadence < 10 sec Filed of view 400 arcsec × 400 arcsec ItemDescription Telescope Wolter-I telescope: diameter of aperture: ~25 cm Focal plane detector Back-illuminated CMOS-APS Energy range 0.5 – ~10 keV Energy resolution ~150 eV at 5.9 keV Plate scale 0.5 arcsec sampling Spatial resolution 1.0 arcsec within 200” off-axis distance Exposure cadence Photon integration mode: < 1 sec Photon counting mode: 10 (20) sec for 2” (1”) area Filed of view Photon integration mode: 400 arcsec × 400 arcsec Photon counting mode: ~80 arcsec × 400 arcsec (baseline) ~200 arcsec × 400 arcsec (goal; cover NS×EW extent of ARs) XIT/NI

XIT(GI, NI) ItemScience requirementsScience backgrounds Related hardware limitations Wavelength selection GI: soft X-rays 0.5 – 5 keV (baseline) 0.5 – 10 keV (goal) NI: some from 6 EUV bands GI: revealing the site of heating in the corona NI: image low corona as well as flare high temperature plasmas GI: photon-counting possible in soft X-rays NI: contribution of many other lines Wavelength resolution λ/Δλ GI: ΔE ~ 150 eV NI: λ/Δλ > 30 GI: obtain emission-line structure in energy spectrum NI: avoid confusion due to nearby emission lines GI: available energy resolution of Si NI: resolution of multi-layers < 40 Spatial resolution GI: 1.0” (0.5” sampling) NI: 0.2” (0.1” sampling) GI: ~1/3 scale size of known flare structures near reconnection site NI: coronal volume filling factor ~0.1 from Hinode observations of 2” spatial resolution GI: telescope length < spacecraft NI: trade between spatial resolution and wide field coverage Field of view GI: -integration mode: 400×400 arcsec -ph-counting mode: 80×400 arcsec NI: 400×400 arcsec GI & NI: Full coverage of an active region GI: - APS detector format of 2K×2K and spatial sampling - on-board ph-counting speed NI: CCD format of 4K×4K and spatial sampling Exposure cadence GI: ph-integration mode < 1 sec ph-counting mode 10 (20) sec for 2” (1”) area NI: < 10 sec GI: rapid heating of coronal structures NI: Faster cadence than LEMUR for providing context images GI: - Effective area NI: readout speed of 4K×4K (can be improved by CMOS) telemetry amount