EIS - MSSL/NRL EUV Imaging SpectrometerSOT - ISAS/NAOJ Solar Optical TelescopeXRT - SAO/ISAS X-ray TelescopeFPP - Lockheed/NAOJ Focal Plane Package

Mission Characteristics

• Launch date: August 2006• Launch vehicle: ISAS MV• Mission lifetime: 3 years

• Orbit: Polar, sun synchronous• Inclination: 97.9 degrees• Altitude: 600 km. • Mass: 900 kg

• Large Effective Area in two EUV bands: 170-210 Å and 250-290 Å– Multi-layer Mirror (15 cm dia ) and Grating; both with optimised Mo/Si Coatings– CCD camera; Two 2048 x 1024 high QE back illuminated CCDs

• Spatial resolution: 1 arcsec pixels/2 arcsec resolution

• Line spectroscopy with ~ 25 km/s pixel sampling

• Field of View ： – Raster: 6 arcmin×8.5 arcmin; – FOV centre moveable E – W by ± 15 arcmin

• Wide temperature coverage: log T = 4.7, 5.4, 6.0 - 7.3 K

• Simultaneous observation of up to 25 lines

EIS - Instrument Features

Slit Exchange Mechanism

Primary Mirror

Entrance Filter

Concave Grating

Filter

CCDs

Shutter

1939 mm

1440 mm

1000 mm

EIS Optical Diagram

Grating

Front Baffle

Entrance Filter

Primary Mirror

CCD Camera

Installation of Key Subsystems in Structure

Primary Mirror Grating

Entrance Filter Holder

Dual CCD Camera

Filter Holder Installed

EIS Instrument Completed

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

Emission Lines on EIS CCDs

1024 pixels

• Four slit/slot selections available

• EUV line spectroscopy - Slits - 1 arcsec 512 arcsec slit - best spectral resolution - 2 arcsec 512 arcsec slit - higher throughput

• EUV Imaging – Slots – Overlappogram; velocity information overlapped– 40 arcsec 512 arcsec slot - imaging with little overlap– 250 arcsec 512 arcsec slot - detecting transient events

Slit and Slot Interchange

EIS Field-of-View (FOV)

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

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

AR: active region

Expected Accuracy of Velocity

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

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 strongest spectral lines

• Line Width Maps (NT Velocity):Line Width Maps (NT Velocity): – images of region being rastered from

second moments of the strongest spectral lines

Norikura coronagraph observations of all three of these parameters

The first 3 months….

• Flare trigger and dynamics: Spatial determination of atial determination of evaporation and turbulence in a flareevaporation and turbulence in a flare

• Active region heating: Spatial determination of the velocity patial determination of the velocity field in active region loopsfield in active region loops

• Coronal Hole Boundaries: Measurement of intensity and easurement of intensity and velocity field at a coronal hole boundaryvelocity field at a coronal hole boundary

• Quiet Sun Brightenings: Determination of the relationship etermination of the relationship between different categories of quiet Sun events.between different categories of quiet Sun events.

Active Regions

• connect the photospheric velocity field to the signatures of coronal heating. This will allow us to determine the dominant heating mechanism in active regions, and will be extended to other coronal brightenings.

• search for evidence of waves in loops and make use of observations for coronal seismology

• study dynamic phenomena within active region loops.

Quiet Sun• link quiet Sun brightenings and explosive events to

the magnetic field changes in the network and inter-network to understand the origin of these events.

• determine the variation of explosive events and blinkers with temperature.

• Search for evidence of reconnection and flows at junctions between open and closed magnetic field at coronal hole boundaries.

• Determine the impact of quiet Sun events on larger scale structures within the corona.

• Determine physical size scales using density diagnostics.

Solar Flares

• determine the source and location of flaring and identify the source of energy for flares. EIS will measure the velocity fields and observe coronal structures with temperature information. Hence will allow us to address the trigger mechanism.

• detection of reconnection inflows, outflows and the associated turbulence which play the pivotal role in flare particle acceleration.

Coronal Mass Ejections

• determine the location of dimming (and the subsequent velocities) in various magnetic configurations allowing us to determine the magnetic environment that leads to a coronal mass ejection.

• The situations to be studied include filaments, flaring active regions and trans-equatorial loops.

Large Scale Structures

• determine the temperature and velocity structure in a coronal streamer

• determine the velocity field and temperature change of a trans-equatorial loop, and search for evidence of large-scale reconnection.

• Using a low-latitude coronal hole, search for evidence of the fast solar wind.

Information is maintained on our website;http://www.mssl.ucl.ac.uk/www_solar/solarB/

The EIS science planning guide shows details of the 3 month plan studies including line choices, which slit/slot, FOV etc.

The planning software will be released into SSW in the autumn. Quicklook software etc. is already in SSW. Details are on the website.

The next solar-B science meeting will be in Kyoto in November.