The Solar-B Mission Len Culhane – EIS Principal Investigator Louise Harra – UK EIS Project Scientist Mullard Space Science Laboratory University College London

SUMMARY The Solar-B mission is outlined and the instruments described – EUV Imaging Spectrometer (EIS) in more detail Solar-B mission operations are described proposal submission is discussed EIS planning software is summarized possible joint observations with other missions suggested The Solar-B priority science plan for the first 90 days after commissioning is reviewed ISSI – Proba Team, 21st June, 2006

Solar-B Spacecraft EIS - MSSL/NRL/BIRM/RAL → EUV Imaging Spectrometer SOT - ISAS/NAOJ → Solar Optical Telescope XRT - SAO/ISAS → X-ray Telescope FPP - Lockheed/NAOJ → Focal Plane Package EIS SOT FPP XRT EIS – UiO → QL Software ESA/NORWAY → Svalbard Ground Station ISSI – Proba Team, 21st June, 2006

Mission Characteristics Launch date: 23rd September, 2006 Launch vehicle: ISAS MV Mission lifetime: 3 years Orbit: Polar, Sun Synchronous Inclination: 97.9o Altitude: 610 km. Mass: 900 kg Mission control: ISAS/Uchinoua Data downlink: Uchinoura → 4 orbits/day Svalbard → 15 orbits/day ISSI – Proba Team, 21st June, 2006

Solar-B Science Summary Establish the mechanisms responsible for heating the corona in active regions and the quiet Sun Active region evolution Nature of sub-photospheric magnetic flux tubes Upper atmosphere heating and wave energy Determine the mechanisms responsible for transient phenomena, such as flares and coronal mass ejections Flares and the role of magnetic reconnection Photospheric magnetic field helicity and CMEs Investigate the processes responsible for energy transfer in the quiet Sun Origin and nature of quiet Sun magnetic fields Flux cancellation and ephemeral regions Network and weak internetwork magnetic fields ISSI – Proba Team, 21st June, 2006

Solar-B Mission Instruments Solar Optical Telescope (SOT) Largest optical telescope (d = 0.5m) to observe Sun from space Diffraction-limited (0.2 – 0.3 arc sec) imaging in range 3880 – 6680 Å Vector magnetic field and velocity measurement at the photosphere X-Ray Telescope (XRT) High angular resolution ( < 2 arc sec) coronal imaging Wide temperature coverage: 1 MK < Te < 30 MK EUV Imaging Spectrometer (EIS) Coronal raster imaging at 2 arc sec Plasma diagnostics (Te, ne, v) in 170 – 210Å and 250 – 290Å ranges ISSI – Proba Team, 21st June, 2006

FPP Optical Component Layout Littrow Mirror Folding Mirror 448 x 1024 CCD Scanning Mirror Polarizing BS X3 Mag lens Folding Mirror Shutter Slit Field lens Grating Field lens Preslit X2 Mag lens Shutter 2048 x 4096 CCD Filterwheel Birefringent Filter Telecentric lenses Field Mask Beam Distributor Secondary Primary CLU Tip Tilt Mirror Filterwheel 50 x 50 CCD Reimaging Lens Folding Mirror OTA Common Optics CT NFI BFI SP Demag lens Image Offset Prisms Folding Mirror Polarization Modulator ISSI – Proba Team, 21st June, 2006

Filtergraph Fields of View Rectangle shows the Narrowband Filter FOV, 320 x 160 arc sec with 0.08 arc sec pixels (4096 x 2048) - inner square is 160 x 160 arc sec Broadband Filter system has higher magnification (0.053 arc sec pixels) to preserve SOT diffraction- limited resolution Broadband Filter FOV is 216 x 108 arc sec Both filter systems share a single CCD. ISSI – Proba Team, 21st June, 2006

Filtergraph Observables Filtergrams Broad-band Filter Imager: all 6 bands - only observable made by BFI Narrow-band Filter Imager: all 9 lines and nearby continuum Dopplergrams Images Doppler shift of a spectral line - line of sight velocity Longitudinal Magnetograms Location, polarity and estimate of flux of magnetic field components along the line-of-sight Stokes Parameters I, Q, U, V Analysis of I, Q, U, V at multiple wavelengths in a spectral line yields vector magnetic field measurements → vector magnetograms, also from spectropolarimeter ISSI – Proba Team, 21st June, 2006

Solar-B X-ray Telescope (XRT) Schematic Grazing incidence telescope; average glancing angle 0.9o PSF and detector pixel sizes are ~ 1 arc sec – resolution ~ x 2.5 better than Yohkoh SXT Ageom is 3.3 cm2 Focal length is 2.7m Inner diameter is 35cm CCD (2k x 2k) gives full-sun (33”) images Focus adjustment for optimum on-axis or wide field resolution ISSI – Proba Team, 21st June, 2006

X-ray Telescope Response Telescope has ~ three times greater effective area than Yohkoh SXT Nine filters cover 1 MK < Te < 30 MK with Te resolution D (log Te) = 0.2 White light (G-band) solar images can be registered on the CCD at one filter wheel position; allows X-ray and EIS to visible image alignment XRT full-Sun observables: → 33 arc sec X-ray & white light images ISSI – Proba Team, 21st June, 2006

EIT and TRACE - EUV Coronal Images Impact of better XRT resolution is shown in a comparison of SOHO EIT and TRACE EUV images Resolution of XRT betters that of the Yohkoh SXT by the same margin (x 2.5) as a) TRACE images better b) EIT images The SXT and TRACE images shown are on the same scale and are of the same coronal structures In full-disk mode, the effective resolution improvement over Yohkoh SXT is ~ x 5 b a ISSI – Proba Team, 21st June, 2006

EIS - Instrument Features Large Effective Area in two EUV bands: 170-210 Å and 250-290 Å Multi-layer Mirror (15 cm dia ) and Grating; both with matching optimized Mo/Si Coatings CCD camera; Two 2048 (l) x 1024 high QE back illuminated CCDs Spatial resolution: 1 arc sec pixels/2 arc sec resolution Line spectroscopy with ~ 25 km/s pixel sampling Field of View： Raster: 6 arc min × 8.5 arc min; FOV centre moveable E – W by ± 15 arc min Wide temperature coverage: log T = 4.7, 5.4, 6.0 - 7.3 K Simultaneous observation of up to 25 lines ISSI – Proba Team, 21st June, 2006

EIS Optical Diagram Primary Mirror Entrance Filter CCD Camera Grating Front Baffle Entrance Filter Primary Mirror CCD Camera ISSI – Proba Team, 21st June, 2006

Slit and Slot Interchange Four slit/slot selections available EUV line spectroscopy - Slits - 1 arc sec  512 arc sec slit - best spectral resolution - 2 arc sec  512 arc sec slit - higher throughput EUV Imaging – Slots - Velocity information overlapped - 40 arc sec  512 arc sec slot - imaging with little overlap - 250 arc sec  512 arc sec slot - detecting transient events ISSI – Proba Team, 21st June, 2006

for 40 arc sec Slot Imaging Strong Isolated Lines for 40 arc sec Slot Imaging Short Wavelength Band Ion l (Å) Fe XI 188.2 Fe XXIV 192.0 Ca XVII 192.8 Fe XII 195.1 Fe XIII 202.0 Fe XIII 203.8 Long Wavelength Band Ion l (Å) Fe XXIV 255.1 He II 256.3 Fe XVI 263.0 Fe XIV 270.5 Fe XIV 274.2 Fe XV 284.1 ISSI – Proba Team, 21st June, 2006

EIS Field-of-View 512  900  Raster-scan range Shift of FOV center with coarse-mirror motion 250  slot 40  360  512  EIS Slit Maximum FOV for raster observation ISSI – Proba Team, 21st June, 2006

EIS Effective Area Primary and Grating: Measured - flight model data used Filters: Measured - flight entrance and rear filters CCD QE: Measured - engineering model data used Following the instrument end-to-end calibration to ± 25%, analysis suggests that above data are representative of the flight instrument ISSI – Proba Team, 21st June, 2006

Science Observables Observation of single lines  w Observation of single lines Line intensity and profile Line shift () → Doppler motion Line width (w) and temperature → Nonthermal motion Observation of line pair ratios Temperature Density Observation of multiple lines Differential emission measure ISSI – Proba Team, 21st June, 2006

EIS Sensitivity Detected photons per 11 per 1 sec exposure Ion Wavelength (A) logT Nphotons AR M2-Flare Fe XVI 251.07 6.40 - 108 Fe XXII 253.16 7.11 71 Fe XVII 254.87 6.60 109 Fe XXVI 255.10 7.30 3.3103 He II 256.32 4.70 16 3.6103 Si X 258.37 6.11 14 62 262.98 15 437 Fe XXIII 263.76 7.20 1.2103 Fe XIV 264.78 6.30 20 217 270.51 17 104 274.20 76 Fe XV 284.16 6.35 111 1.5103 Ion Wavelength (A) logT Nphotons AR M2-Flare Fe X 184.54 6.00 15 36 Fe XII 186.85 / 186.88 6.11 13/21 105/130 Fe XXI 187.89 7.00 - 346 Fe XI 188.23 / 188.30 41 / 15 110/47 Fe XXIV 192.04 7.30 4.0104 192.39 46 120 Ca XVII 192.82 6.70 31 1.8103 193.52 135 305 195.12 / 195.13 241/16 538/133 Fe XIII 200.02 6.20 20 113 202.04 35 82 203.80 / 203.83 7/20 38/114 ISSI – Proba Team, 21st June, 2006

Solar-B Mission Operations

Solar-B Mission Data Acquisition SOT/FPP Data a) b) c) Data are stored on-board in 8 Gbit memory Instrument memory allocations are: - SOT/FPP → 70% - EIS/XRT → 15% each Data downlinked to Svalbard ground station (ESA/Norway) on 15 orbits/day - memory dumped once per orbit EIS average data rate → 45 kbps Command uplinks only from Uchinoura - four memory dumps per day Quick-look assessed at ISAS and Uchinoura ISSI – Proba Team, 21st June, 2006

Solar-B Mission Data Distribution Level-0 and Cal Data Level-2 Data (FPP) Level - Reformat Solar B Database in Japan in US in UK FPP Level 1 and -2 Reformat at Lockheed Data distributed to UK, US and Norway in compressed level – 0 form Because of complexity, FPP data are transmitted in level – 0 form to Lockheed Palo Alto They are processed to level – 2 to produce vector and scalar magnetograms These products are then sent to Japan and onward to UK and Norway ISSI – Proba Team, 21st June, 2006

Solar-B Mission Operations Mission operations will be conducted from the ISAS Spacecraft Operations Centre in Fuchinobe, Japan Solar-B team observing plans and community proposals will be discussed at monthly meetings Each instrument team will have a Scientific Schedule Coordinator who will organize the preparation of instrument proposals and their integration in the overall mission observing plan Weekly and daily planning meetings allow flexibility to respond to changing solar conditions ISSI – Proba Team, 21st June, 2006

Operations Roles A) Solar-B Mission Solar-B Chief Planner (CP) Provided by the instrument teams in rotation, one week shifts Chief Planner Assistant (CPA) Scientific Schedule Coordinators (SSC) One for each instrument Assistance from other participating countries EIS SSC based in MSSL with visits to Japan B) Individual Instruments (EIS-specific Roles) Chief Observers (CO) (SOT, XRT, EIS): One person for each instrument, one week shifts Instrument Software Coordinators (ISCO): EIS person initially at ISAS, then at MSSL; planning software from RAL Instrument System Engineers (ISE): EIS person at ISAS for commissioning, then at MSSL ISSI – Proba Team, 21st June, 2006

EIS Operations Staffing NRL UK/Norway/Japan Bradley Sun --------- Culhane Harra, Other UK Mariska MSSL (x5) Doschek RAL (x2) Rainnie Young EIS Planner (Rotator @ 3 weeks each) Landi/Warren Norway (x2) GSFC/Davila Hansteen Wikstol NAOJ (x2) ISAS GMU/Dere Hara Watanabe Discussion points for this slide: To point out the extent of the NRL activities, including the work done in the UK; I will ask Clarence to summarize the UK activities and to emphasis the complexity of the NRL delivered components Post Doc/ Brooks ISAS On-Site (1 year) Post Doc/ MSSL ISAS On-Site (1 year) Williams First year of operation (Minimum)

EIS Planning Tool Software Planning tool software is in SSW Users will need to install the EIS SolarSoft tree Study Definition Line Lists Raster Definition Planners then export studies to ASCII format E-mail a formatted file and a science case to a dedicated account at MSSL ISSI – Proba Team, 21st June, 2006

EIS Planning Tool - line list interface ISSI – Proba Team, 21st June, 2006

Planning Tool – make/edit raster ISSI – Proba Team, 21st June, 2006

5. Planning Tool – make/edit study ISSI – Proba Team, 21st June, 2006

Solar-B Mission Science for the First 90 Days

SOT Initial Science Plan Active region tracking: - Emerging AR - Mature/decaying AR - Flaring AR - Subsurface flows - MHD waves Quiet Sun: - Network flux dynamics - Internetwork flux - Convective flow structure Irradiance: - Activity belt - Polar regions Prominences/Filaments - Prominence at limb/Filaments on disc - Track boundary evolution ISSI – Proba Team, 21st June, 2006

XRT Initial Science Plan Flares from dynamic AR on disk:  Follow AR across disk, flare program loaded - Deploy range of filters and FoV sizes - Flare topology and energetics Track modest (emerging or decaying) active region on disc:  Image with large, medium and small FoVs - Structure, energetics and dynamic behaviour - AR evolution; track centre to limb? Quiet Sun/X-ray Bright Points:  Multi-filter study of bright points - Thermal structure and dynamics - Life-cycle statistics Quiet Sun/coronal holes  Single filter for boundary imaging - Track boundary evolution Quiet Sun/filament  Magnetic structure around filament - Track filament for 1-2 days ISSI – Proba Team, 21st June, 2006

EIS Initial Science Plan Flare trigger and dynamics:  Spatial determination of evaporation and turbulence in a flare - Characterize AR topology - Measure key structures in detail - Flare trigger response for early velocity measurement Active region heating:  Spatial determination of v, Te and ne in active region structures - High time cadence sit and stare observations; dynamics - Observe AR global changes - Velocity measurements (± 3 km/s) Quiet Sun and coronal hole boundary:  Correlate coronal Te, ne and v with magnetic topology - Study corona above two supergranule cells - Study corona above bright point or explosive event - Observe above a coronal hole boundary Quiet Sun and Prominences (assume no available AR)  Spatial determination of v, Te and ne in surrounding regions -Register and follow eruption ISSI – Proba Team, 21st June, 2006

90 Day Observing Programme Summary Topic SOT XRT EIS AR Tracking a) Emerging AR √ b) Complex AR/Flares c) Decaying AR Quiet Sun a) Network Small events/ Bright Points Quiet Sun b) Intra-network Small events/ Bright Points Spicules Magnetic connections Prominences/Filaments ISSI – Proba Team, 21st June, 2006

90 Day Observing Programme Summary Topic SOT XRT EIS Helioseismology/AR Tracking √ Helioseismology/QS/ Disc centre Helioseismology/ Polar regions Coronal Holes Coronal Holes/ Polar Plumes Irradiance/ a) AR Tracking √/irradiance? b) Activity belt repointings Small events Coronal Hole Boundaries ISSI – Proba Team, 21st June, 2006

EIS Core Science Programme AR Heating → dynamic phenomena in loops Coronal/Photospheric velocity field comparison in AR Coronal Seismology → waves in AR structures AR Helicity content → CMEs, magnetic clouds Evolution of trans-equatorial Loops Flare produced plasma → source, location and triggering Flare reconnection → inflow and outflow Quiet Sun transient events → network, network boundaries, CH boundaries, size scales CME Onsets → dimming, filaments, flux-ropes, flaring AR, trans-equatorial Loops Evolution of large coronal structures → streamers, large-scale reconnection, slow Solar Wind ISSI – Proba Team, 21st June, 2006

Some Possible Joint Observations Solar-B Instruments: Active Region study campaign (SOT/EIS/XRT) Emission measure distributions in AR structures (EIS/XRT) AR helicity content and CME launches (SOT/EIS/XRT) Magnetic topologies in small events (SOT/EIS/XRT) Network and intra-network small event energies and velocities (EIS/SOT) Plasma and magnetic structures above Coronal Hole boundaries (EIS/SOT) Reconnection flows in flares (EIS/XRT) Other Missions: CME launching, topology and magnetic clouds (Solar-B, STEREO, ACE) CME dimming outflow velocities; their relation to CMEs (Solar-B/EIS, STEREO) Trans-equatorial loop and filament eruptions (Solar-B/EIS, XRT, STEREO) Coronal (EIT) waves and their relation to CMEs (Solar-B/EIS, XRT, STEREO) Intensity and velocity studies of waves in AR structures (Solar-B, TRACE, SDO) Impulsive flares and sub-surface wave propagation (Solar-B, TRACE, SDO) ISSI – Proba Team, 21st June, 2006

END OF TALK ISSI – Proba Team, 21st June, 2006

Processed Science Data Products Intensity Maps (Te, ne): – images of region being rastered from the zeroth moments of strongest spectral lines Doppler Shift Maps (Bulk Velocity): – images of region being rastered from first moments of the Line Width Maps (Non-thermal Velocity): – images of region being rastered from second moments of the strongest spectral lines ISSI – Proba Team, 21st June, 2006

EIS Data Flow CCD Readout Electronics EIS ICU S/C MDP Data compression DPCM(loss less) or 12bit-JPEG Small spectral window (25 max) CCD Readout Electronics 2Mbps max 1.3 Mbps EIS ICU S/C MDP control Large hardware CCD window Observation table  250 kbps max for short duration,  45 kbps average 1 slit obs. 40 slot obs. 250 slot obs. Spec.width 16 40 250 Spatial width 256" 512" 256" No. of lines 8 4 4 Compression 20% 20 % 20% Cadence 2 sec 5 sec 15 sec Rate 38.4 kbps 38.4 kbps 40 kbps Average rate depends on number of downlink station. Telemetry data format 10 min cadence for 44 rastering ISSI – Proba Team, 21st June, 2006

Installation of Key Subsystems in Structure Primary Mirror Grating Dual CCD Camera Filter Holder Installed EIS Instrument Completed Entrance Filter Holder ISSI – Proba Team, 21st June, 2006

Vector Magnetograms Spectra of two Fe lines at 6301.5 Å and 6302.5 Å and nearby continuum are exposed with a 0.16 x 164 arcsecond slit The Spectro-polarimeter (SP) can scan across a 160 x 320 arc sec FOV while the CT and Filter FOVs are fixed In normal mode, the SP scans 160 arc sec in 83 min Fast maps are 2.8 times quicker hence 160 arc sec in 30 min Magnetic field measurement: - B (longitudinal) to ± 3 G - B (transverse) to ± 30 G - Field direction to ± 1o ISSI – Proba Team, 21st June, 2006

Velocity Measurement Accuracy Bright AR line Flare line Photons (11 area)-1 sec-1 Photons (11 area)-1 (10sec)-1 Doppler velocity Line width Number of detected photons ISSI – Proba Team, 21st June, 2006

EIS and XRT Science Coronal heating mechanisms - Multi-filter XRT and multi-line EIS slot images study thermodynamic properties of coronal structures EIS and XRT can show the AR coronal structures that have significant large scale flows Rapid intensity fluctuations observed by XRT combined with velocity maps from EIS and SOT Dopplergrams will establish role of waves and flows in different parts of an AR Magnetic reconnection and coronal dynamics XRT will observe statistically significant numbers of small reconnection events Comparing location, energetics, and duration of these events (XRT, EIS, and SOT filtergrams) with evolving photospheric magnetic field will allow first quantitative study of - conditions necessary for reconnection - efficiency of the reconnection - coronal impact of the reconnection Photospheric-coronal coupling For ARs, need to trace magnetic connectivity → photosphere – chromosphere -corona Spectral imaging with EIS and SOT - allows identification of loop footpoints - associates footpoints with photospheric magnetic features Flare events and coronal mass ejections. Topological properties of flares and CMEs studied using non-linear force-free field models from SOT vector data - Follow AR evolution and identify the coronal sites of flare or CME initiation - Discover magnetic null points above flaring active regions and track AR magnetic helicity changes ISSI – Proba Team, 21st June, 2006

EIS Instrument Calibration If fl in photons cm-2 s-1 sr-1 is the intensity of the solar radiation at wavelength l, the number of photons registered in each detector pixel per second is: Nl = fl A wd Tffa(l) Tspider Rm(l) Tsef(l) Eg(l) Ed(l) where A is the mirror geometric area and wd is the solid angle per detector pixel Tspider is the transmission of the entrance filter spider support structure Tffa(l), Tsef(l) are the transmissions of the Al entrance and spectrometer filters - filters on an 85% transmission support mesh which is included in T values Rm(l), Eg(l) are the coated mirror and grating efficiencies Ed(l) is the CCD detector quantum efficiency ISSI – Proba Team, 21st June, 2006

EIS Calibration Spectra – 250" Slit Calibration has been carried out with the source used for SOHO CDS calibration (Hollandt et al., 2002, Lang et al., 2000) Source is radiometrically calibrated by PTB, Berlin at the BESSY I electron storage ring Stable high-current hollow-cathode discharge lamp provides appropriate EUV emission lines Following EIS calibration, the source will be re- calibrated at BESSY II NRL Penning source also used for alignment and full aperture illumination ISSI – Proba Team, 21st June, 2006

EIS Calibration Spectrum – 2" Slit Al III, Al IV and Ne IV lines ISSI – Proba Team, 21st June, 2006

Nonthermal Velocity in Flares Te Gradual increase of vnt at the precursor phase of a flare is reported by Harra, Matthews, & Culhane (2001). Detecting of flares in a slit scanning observation is the only way to identify this precursor. Identification of site of large non-thermal velocity in imaging spectroscopy will be very important in understanding the physics of precursor phase. vnt vnt I (S XV) vnt BATSE Ch 1 Harra, Mattews, & Culhane 2001, Ap.J, 549, L245-248 ISSI – Proba Team, 21st June, 2006

Reconnection Inflow Evidence of 2D-reconnection inflow for a long-duration event is reported by Yokoyama et al. (2001) from an EUV imaging observation EIS will detect the reconnection inflow as a Doppler shift in emission line spectra Observation near the limb will be important to detect reconnection inflow Hot reconnection outflow may be detected in Fe XXIV slot observations Movie sequence From Yokoyama et al. 2001, ApJ, 546, L69-72 ISSI – Proba Team, 21st June, 2006

Coronal Mass Ejection Onset Coronal dimming directly associated with outflow (Harra & Sterling, 2001) Bottom panel shows a CDS O V velocity map for a disc event where ~ 80 km/s outflow is seen from the edge of the dimming region CDS limb event observations show intensity reduction and outflow velocities in He I, O V, Mg IX and Fe XVI Using EIS: - select HeII, SiVII, Fe X, Fe XIII, Si X, Fe XIV, Fe XV, Ca XVII lines - raster slit over 6’ x 8’ in 30 min. - raster 40” slot over 6’ x 8’ in 1 min. Respond more quickly to dimming onsets ISSI – Proba Team, 21st June, 2006

Coronal Hole Boundaries CH boundaries are not well understood - EIS will determine the velocity field in this important region. Using EIS: - Select HeII, SiVII, Si X, Fe XII, Fe XI, Fe X lines - Sit and stare studies with the 1" slit alternated with 300" x 300" rasters Movie sequence ISSI – Proba Team, 21st June, 2006

Instruments and Spacecraft Bus Following completion of final thermal vacuum test (20th March to 4th April, 2006):  Instruments separated  Work in progress on ACS system in bus module EIS flight filters were installed on Monday, 19th June Spacecraft arrives at the Uchinoura launch site on 1st August Bus Module Instruments ISSI – Proba Team, 21st June, 2006