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The Solar-B EUV Imaging Spectrometer: an Overview of EIS

The Solar-B EUV Imaging Spectrometer: an Overview of EIS. J. L. Culhane Mullard Space Science Laboratory University College London. Primary Mirror. Entrance Filter. CCD Camera. Front Baffle. Grating. EIS Optical Diagram. Each element measured independently at Brookhaven

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The Solar-B EUV Imaging Spectrometer: an Overview of EIS

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  1. The Solar-B EUV Imaging Spectrometer:an Overview of EIS J. L. Culhane Mullard Space Science Laboratory University College London

  2. Primary Mirror Entrance Filter CCD Camera Front Baffle Grating EIS Optical Diagram EIS Instrument Overview

  3. Each element measured independently at Brookhaven Complete instrument calibrated end-to-end at RAL Instrument contamination budget maintained by keeping at positive dry Nitrogen pressure Continuous QCM monitoring pre and post launch Temperature insensitive lines in QS measured throughout mission Two GSFC EUNIS rocket flights during mission Philosophy based on SOHO CDS approach. EIS Calibration EIS Instrument Overview

  4. 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, analysis indicates that the above data are representative of the flight instrument EIS Instrument Overview

  5. l/Dl ~ 4600 57.7 mÅ 58.1 mÅ 57.9 mÅ Spectroscopic Performance Long Wavelength Band • Ne III lines near 267 Å from the NRL Ne–Mg Penning discharge source • Gaussian profile fitting gives the FWHM values shown in the right-hand panel EIS Instrument Overview

  6. l/Dl ~ 4000 47 mÅ 47 mÅ Spectroscopic Performance Short Wavelength Band • Mg III lines near 187 Å from the NRL Ne–Mg Penning discharge source • Gaussian profile fitting gives the FWHM values shown in the right-hand panel • Following further new line identifications in the Penning source spectrum, an absolute • wavelength scale may be possible EIS Instrument Overview

  7. END OF TALK EIS Instrument Overview

  8. 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  w Observables EIS Instrument Overview

  9. Shift of FOV center with coarse-mirror motion Maximum FOV for raster observation 360  900  900  512  512  512  Raster-scan range 250  slot 40  slot EIS Slit EIS Field-of-View EIS Instrument Overview

  10. EIS Sensitivity Detected photons per 11 area of the Sun per 1 sec exposure. EIS Instrument Overview

  11. Flare line Bright AR line Doppler velocity Line width Doppler Velocity and Line Width Uncertainties • One-s uncertainty in: - Doppler shift (dv in km/s) - Non-thermal line width (dFWHM in km/s) • Values are plotted against number of detected photons in the line for: - Bright AR line (Fe XV/284 Å) - Flare line (Fe XXIV/255 Å) Photons (11 area)-1 sec Photons (11 area)-1 (10sec)-1 EIS Instrument Overview

  12. Flare Trigger and Dynamics: Spatial determination of evaporation and turbulence in a flare Active Region Heating: Spatial determination of velocity field in AR loops for a range of Te values Quiet Sun Studies: Correlate coronal Te, ne, v with the magnetic topology inferred from FPP Coronal Holes and Hole Boundaries: Measurement of intensity and velocity field at a coronal hole boundary and at selected sites in coronal holes First 90 Day Observing Plan EIS Instrument Overview

  13. Following SOHO CDS, the EIS instrument will provide the next steps in EUV spectral imaging of the corona: x 10 enhancement in Aeff from use of multilayers and CCDs x 5 enhancement in spectral resolution x 3 enhancement in spatial resolution Like CDS; absolute calibration performed to ± 20% EIS will: Address a broad range of coronal science topics Enable major goals of Solar-B mission by relating coronal response to magnetic flux emergence and material flows SUMMARY EIS Instrument Overview

  14. Large Effective Area in two EUV bands:170-210 Å and 250-290 Å Multi-layer Mirror (15 cm dia ) and Grating; both with optimized Mo/Si Coatings CCD camera; Two 2048 x 1024 high QE back illuminated CCDs Spatial resolution: 1 arc sec pixels/2 arc sec resolution Line spectroscopy with ~ 25 km/s per 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/spectral windows EIS - Instrument Features EIS Instrument Overview

  15. EIS on the Solar-B Spacecraft Roles and Responsibilities UK (MSSL (PI), Birmingham, RAL):  CCD cameras, Structure, On-board Processor, Filter Housing, Calibration USA (NRL, GSFC, Columbia): Optics, Coatings, Mechanisms, Filters, Japan (NAOJ, ISAS): Testing, Integration with Spacecraft Norway (UiO):`  EGSE Software All participants are involved in Post-launch Mission Operations and Data Analysis EIS Instrument Overview

  16. 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 strongest spectral lines • Line Width Maps (Non-thermal Velocity): – images of region being rastered from second moments of the strongest spectral lines EIS Instrument Overview

  17. Flare line Bright AR line Doppler velocity Line width Doppler Velocity and Line Width Uncertainties Photons (11 area)-1 sec-1 Photons (11 area)-1 (10sec)-1 Number of detected photons EIS Instrument Overview

  18. Raster Drive Primary Mirror Primary Mirror Assembly • Multilayer-coated mirror • shown installed in the • instrument structure EIS Instrument Overview

  19. Grating Assembly Grating Focus Drive EIS Instrument Overview

  20. Atomic Force Microscope Profile of Laminar Grating • AFM profile of grating grooves in a • 1 μm x 1 μm region near grating center • for grating FL-8 • . • Mean groove depth is 6.4 nm and the • land width is 108 nm(4200 lines/mm) • Grating substrates fabricated by Zeiss • - Holographic technique used to form a • sinusoidal groove pattern • - Ion beam etching used to shape laminar • grooves and to achieve specified groove depth EIS Instrument Overview

  21. Dual CCD Camera CCD Camera and Readout Electronics Camera and associated electronics installed in the instrument structure CCDs with cold finger attachments EIS Instrument Overview

  22. Slit/Slot Wheel - before blackening Shutter Slit/Slot Wheel Slit/Slot and Shutter Assembly EIS Instrument Overview

  23. EIS Instrument Completed EIS Instrument Pre-Calibration EIS Instrument Overview

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