the solar-b euv imaging spectrometer: an overview of eis j. l. culhane mullard space science...

The Solar-B EUV Imaging Spectrometer:

an Overview of EIS

J. L. Culhane

Mullard Space Science LaboratoryUniversity College London

AIA HMI Team Meeting , Monterey 13-17 Feb., 2006

EIS Instrument Overview

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EIS Optical Diagram

Grating

Front Baffle

Entrance Filter

Primary Mirror

CCD Camera



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• 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



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EIS Effective Area

Primary and Grating: Measured - flight model data usedFilters: 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



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Spectroscopic PerformanceLong 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

57.7 mÅ58.1 mÅ

57.9 mÅ

~ 4600



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Spectroscopic PerformanceShort 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

47 mÅ 47 mÅ

~ 4000

• Following further new line identifications in the Penning source spectrum, an absolute wavelength scale may be possible



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END OF TALK



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Observables

• 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



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EIS Field-of-View

360

512

EIS Slit

Maximum FOV for raster observation

512

900 900

Raster-scan range

Shift of FOV center with coarse-mirror motion

250 slot

40 slot

512



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EIS Sensitivity

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 6.11 41 / 15 110/47

Fe XXIV 192.04 7.30 - 4.0104

Fe XII 192.39 6.11 46 120

Ca XVII 192.82 6.70 31 1.8103

Fe XII 193.52 6.11 135 305

Fe XII 195.12 / 195.13 6.11 241/16 538/133

Fe XIII 200.02 6.20 20 113

Fe XIII 202.04 6.20 35 82

Fe XIII 203.80 / 203.83 6.20 7/20 38/114

Detected photons per 11 area of the Sun 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 - 3.3103

He II 256.32 4.70 16 3.6103

Si X 258.37 6.11 14 62

Fe XVI 262.98 6.40 15 437

Fe XXIII 263.76 7.20 - 1.2103

Fe XIV 264.78 6.30 20 217

Fe XIV 270.51 6.30 17 104

Fe XIV 274.20 6.30 14 76

Fe XV 284.16 6.35 111 1.5103



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Doppler Velocity and Line Width Uncertainties

Doppler velocity

Line width

Bright AR line Flare line

Photons (11 area)-1 sec Photons (11 area)-1 (10sec)-1

One- uncertainty in: - Doppler shift (v in km/s) - Non-thermal line width ( FWHM 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)



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First 90 Day Observing Plan

• Flare Trigger and Dynamics: Spatial determination of evaporation and turbulence in a flarepatial determination of evaporation and turbulence in a flare

• Active Region Heating: Spatial determination of velocity field in AR loops for a range of TSpatial determination of velocity field in AR loops for a range of Tee values values

• Quiet Sun Studies: Correlate coronal TCorrelate coronal Tee, n, nee, v with the magnetic topology inferred from FPP, 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 Measurement of intensity and velocity field at a coronal hole boundary and at

selected sites in coronal holesselected sites in coronal holes



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SUMMARY

• 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



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• 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



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EIS on the Solar-B SpacecraftRoles 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 SpacecraftNorway (UiO):` EGSE Software

All participants are involved inPost-launch Mission Operationsand Data Analysis



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Processed Science Data Products

• Intensity Maps (TIntensity Maps (Tee, n, nee):):

– images of region being rastered from the zeroth moments of

strongest spectral lines

• Doppler Shift Maps (Bulk Velocity):Doppler Shift Maps (Bulk Velocity): – images of region being rastered from first moments of the


• Line Width Maps (Non-thermal Velocity):Line Width Maps (Non-thermal Velocity): – images of region being rastered from second moments of the




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Doppler velocity

Line width

Bright AR line Flare line

Photons (11 area)-1 sec-1

Photons (11 area)-1 (10sec)-1

Number of detected photons

Doppler Velocity and Line Width Uncertainties



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Primary Mirror

Raster Drive

Primary Mirror Assembly

• Multilayer-coated mirror shown installed in the instrument structure



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Grating Assembly

Grating

Focus Drive



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Atomic Force Microscope Profile of Laminar Grating

.

• Mean groove depth is 6.4 nm and the land width is 108 nm (4200 lines/mm)

• AFM profile of grating grooves in a 1 μm x 1 μm region near grating center for grating FL-8

• 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



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Dual CCD Camera

CCD Camera and Readout Electronics

Camera and associated electronics installed in the instrument structure

CCDs with cold finger attachments



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Slit/Slot and Shutter Assembly

Slit/Slot Wheel ShutterSlit/Slot Wheel- before blackening



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EIS Instrument Pre-Calibration

EIS Instrument Completed

the solar-b euv imaging spectrometer: an overview of eis j. l. culhane mullard space science...

Documents

overview of eis

eis instrument overview

eis calibration slide

aia hmi team meeting

flight instrument slide

eis field

fe xii186

fe xiii203