Solar‐C meeting, 11 Nov. 2013 in Takayama

Solar UV‐Visible‐IR Telescope(SUVIT)
K.Ichimoto （Ｋｙｏｔｏ Ｕ.）,Y.Suematsu, Y.Katsukawa , H.Hara, R.Kano(NAOJ), T.Shimizu, K.Matsuzaki (JAXA)
and Solar‐C WG

Many Hinode results are related
to fundamental MHD processes.

waves

ubiquitous
field

magnetic reconnectionflows
turbulence
instability

magneto-convectionBut,, they are not yet contributed to our fullunderstanding of chromosphere and corona..
Limitations of SOT;
- Many features are unresolved.
> 80% of flux are invisible to Hinode/SP (Pietarila Graham+. 2010)- Hinode is blind to chromosphere in terms of diagnostics.
No information of physical quantities, v, B, T, n.

- Insufficient time resolution of spectroscopic observations
G-bandBz (SP)B?
CP

The most significant jump of SUVIT
from the SOT• 3 times higher spatial resolution
 resolve elementary density / temperature structures• High precision spectro‐polarimetry of chromosphere Zeeman / Hanle diagnosis of chromospheric mag. field• Time cadence (especially magnetic field data) capture dynamic evolution of physical conditions in fundamental
plasma process
height

SUVIT
chromospherephotosphereimaging

SOTmag. vel.

1”

0.3”

0.1”

Spatial scale

Gain with a higher spatial resolution（photosphere）
３times higher resolution compared to SOT
 10 times higher sensitivity to magnetic elements

ground 1”

SOT 0.3”
mag.elements [x,y]SUVIT 0.1”
+ vortex , current、mix.pol.
0.1”～ photon mean free path# of detectable mag. elements x 7 (from power-low PDF -1.8)# of detectable interactions x 50
(courtesy by Iida)

With uninterrupted observation, SUVIT will unveil for the first time
the whole picture of magnetic energy generation in the photosphere.

Gain with a higher spatial resolution(chromosphere)
Mysterious spicule

Suematsu, SOT 0.2”, CaH？
Ryutova+ 2008

0.1” width structure= energy & mass flow channels?

Ji+ 2012, BBSO 1.6m NST 10830A & AIA 171A

SUVIT will detect the fine scale channels connecting
photo. /chrom./corona, current sheets, mag.
reconnection, shock fronts,,,

 First quantitative understanding of energy
flows in the chromosphere!

Science requirements
Spatialresolution
Field ofview
WavelengthcoverageWavelength
resolution
Polarimetricsensitivity
Time resolution

Data raterequirement (goal)

reason0.07” for imaging obs.
0.1” for mag. field obs.
0.36” for 2D chrom. mag. field180”x180” (200”x200”) for AR study
8”x8”(10”x10”) for elementary structures

resolve chrom. T &  fine structures
resolve photo. mag. elements (<1)scale of divergent chrom. mag. field ( >1)
Size of a moderate AR
Size of a spicule

393 nm (280nm) – 1083nm

high res. contrast chrom. imaging
photo. & chrom. mag, measurement
Thermal width of spectral lines in photo,/chrom.
Zeeman signal

200,000 for precise photo. mag. field
100.000 for precise chrom. mag. field
50,000 for high res. mag./vel. field
3･10‐4 (10‐4) for chrom. mag. field
10‐3 (10‐4) for photo. mag. fieldB∥~10G, B⊥~100 G
B∥~2G, B⊥~70 G

1sec for imaging obs.
10sec for small FOV mag. obs.
1hr for large FOV mag. obs~2.5 Mbps in average (after compression)~50 Mbps at peak ( “ )Flare evolution
Chrom. dynamic features
AR mag. evolution
ex. Track long term evolution of AR
ex. Diagnose the evolution of dynamic process

Instrument requirements
Spatialresolution
Field ofview
Wavelength
coverage
Wavelength
resolution
Polarimetricsensitivity
Time resolution

Data raterequirement (goal)

Impact on instrument design0.07” for imaging obs.
0.1” for mag. field obs.
0.36” for 2D chrom. mag. field180”x180” (200”x200”) for AR study
8”x8”(10”x10”) for elementary structures

Telescope diameter ~ 1.4m
diffrac. limited optics Str. > 0.8 @633nm
sufficient spatial sampling 0.015~0.02”/pix
Large acceptance angle of optical system
Large format camera
Dual mode (high reso. & wide FOV)
Wide l coating, (restricted glass for 280nm)
chromatic design of imaging optics
Grating size > 20cm,spectrograph f x slit width
Narrowband filter width ~ 0.1A @520nm
Telescope diameter ~ 1.4m, High throughput
Fast camera (~50fr/s), onboard demodulation
High pol. modulation efficiency & calibration
High speed camera
2D spectroscopy (IFU in SP) + 2D scan mech.

393 nm (280nm) – 1083nm
200,000 for precise photo. mag. field
100.000 for precise chrom. mag. field
50,000 for high res. mag./vel. field
3･10‐4 (10‐4) for chrom. mag. field
10‐3 (10‐4) for photo. mag. field
1sec for imaging obs.
10sec for small FOV mag. obs.
1hr for large FOV mag. obs~2.5 Mbps in average (after compression)~50 Mbps at peak ( “ )Large telemetry
Efficient data compression w/ 12bit JPEG

Science requirements are realized by two complementary instruments;
Filtergraph (FG) & Spectro-polarimeter (SP)Spectral resolution


SP/IFU

1sec

2・105

10sec

FG/BFI

105
5・104

1min
104

10min

FG/NFI

1hr
103

1day
1%

SP/slit

0.1%

10”

100”

1000”

1min
1hr
1day

0.01%

Random noise

1weekTime span

FOV

Wavelength coverage• Measure the magnetic field of chromosphere by Zeeman effect extension to longer wavelength is inevitable• Observe chromospheric dynamics with a highest resolution andcontrast
 demand for shorter wavelength, i.e. MgII 280nm
SUVIT candidate lines
Spectrum bands
ContinuumTBD
Mg II k279 nm
CN band
388 nmCa II K393 nmBlue cont. 450 nm
Mg I b517 nmFe I
Na I DFe IHIαCa IIHe I

525 nm589 nm
630 nm
656 nm854 nm1083 nm

SP(x)

BF(x)
(x)
xxx

NFxxxxx
TBD
TBDxx

PurposeT in the upper photosphere
T and V in the chromosphere
Magnetic elements in the photosphere
Structures in the chromosphere
Imaging and T in the photosphere
V and B in the low chromosphere
V and B in the photosphere
V and B in the low chromosphere
V and B in the photosphere
Structures in the chromosphere
T, V, and B in the chromosphere
V and B in the chromosphere

280nm is optional. Technical issues not fully settled down..

SOT lines
H

CaH
D16303

imaging
Spectro‐polarimetry

11

SUVIT lines

HeIH( )MgII kCaII KCaHCaII IR
D16303

imaging
Spectro‐polarimetry

12

SUVIT basic design concept• Maximum usage of the Hinode heritage– An axi‐symmetric aplanatic Gregorian
telescope with 1.4m aperture– Heat dump mirror and 2nd field stop tominimize the heat lord to FG & SP
– FG & SP are connected with the telescopeassy. (TA) by collimated beam via OBU– Common rotating waveplate as a pol.
modulator– Image stabilizing system with a tip‐tilt mirror– Same testing strategy;
optical alignment, opto‐thermal vac.,microvibration, contamination control,,,• But, the new demands make SUVIT a much more challenging
13
instrument than SOT/Hinode!

SUVIT layout

1.41mPMUor PCU

3.1m
heat dump mirror

14

Telescope structure

Tangential support of M2 to prevent thedefocus caused by a thermal effectLight waighted (~90%)
Minimum gravitational deformation
15
when the mirror is in vertical.

Coating on the mirrors
Obs

wavelength

Mg II h&k
280nm

G‐band430nm

Na I D H I Hα589nm 656nm

Ca II IR854nm

Highly enhanced Ag(SAGEM)

He I
1083nmAｌ＋MgF2

We selected Ag coating forAg- high trroughput in Vis.-IR- less heat absorption at the primary irror

a special coating on Ag for 280nm (TBD)
Technical issue remains;– need further development

16

Mg II 280nm
In the current study,
we optimize the system design for 380‐1100nm w/o 280nm
280nm will be included when
‐ definitive scientific justification is made after the study ofIRIS data
‐ it is proven that inclusion of 280nm does not degrade theperformance in Vis.&IR nor introduce significant risk
Decision will be made by spring in the next yearFiltergraph layout
Broad‐bandfilter turret

Narrow‐bandtunable filter• FOV, plate scale (4k x 4k camera):– NB‐High Res: 90” x 90”, 0.0225” pixels– NB‐Wide FOV: 180” x 180”, 0.045” pixels– WB‐High Res: 60” x 60”, 0.015” pixels– WB‐Wide FOV: 180” x 180”, 0.045” pixels
SUVIT Meeting, 12 Dec 2012

T. Tarbell, LMSALSpectro‐polarimeter

Another option; three cameras

20Spectral product
FeI 525nm

Long slit

CaII 854nm

HeI 1083nm

IFU

4 sets of orthogonally polarized spectrum
21

Data acquisitionTo achieve S/N~ 104, we need to collect 108 photons
 high IR sensitivity
 fast readout, onboard accumulation (~1000 frames!)
IR camera

Onboard demodulation  IQUVR

Teledyne Co.
H2RG FPA, SIDECAR ASIC,HgCdTe, 2k x 2k pixels, 18m/pix
Space qualified(TRL-6 for H2RG, TRL-9 for SIDECAR)

Readout 64 frames/sec, (WP 1 sec/rot)22

Lesson from Hinode;

Pointing stability
SOT/Hindoe achieved ~0.02” rms.
SUVIT requires 2 – 3 times higher pointing stability

Critical area

Lesson from Hinode;

Contamination control;
SOT throughput (real)

SOT contamination model

We do not understand exactly the cause of degradation of SOT
throughtput.
 Need further experiments for Solar‐C!

Critical issues
Technical;
••
•
•
•
•

Realization of a diffraction limited large space telescope
Pointing stability, 3 times tight compared with SOT/HinodeOptics to accommodate the MgII 280nm
Contamination control (especially for UV)
Weight & cost!
:Scientific;• Reliable Stokes inversion for chromosphere to reveal– energy carried by waves to solve the heating problem.
– good boundary condition for field extrapolation.
– direct evidence of magnetic reconnection– origin of spicule, prominence, flare,,• How the MgII 280nm contribute to the Solar‐C science goal?
• What does SUVIT’s spatial resolution really see?
• :25

SUVIT block diagram
FG‐CamInternational collaboration

FGP: Filtergraph package

IU: IF unit

TA: Telescope AssyPMU

HK, HTRBSPMU control

HK,HTR

CMU
orCLU

Doors
Top/side command

Mechanism

SPP: Spectrograph package
Scan‐M FW
focus

TTM control

M1

shutter
FG‐MHC

TTM

Adj.

M2

focus FW1&2 TF

TA‐E

CT‐CamSP‐MHC

Grating

HK,HTR

SP‐CamSP‐E
PMU signal

Control,status

PMU signal

CT signal

Control,data

S/C bus

FG‐Econtrol
dataInternational collaboration• JAXA/NAOJ/Univ’s• NASA/ LMSAL/ HAO• Hawaii‐U• ESA• MSSL / MPS• IAC / IAA• Oslo•‐‐ telescope, SP, integration‐‐ FG‐‐ IFU experiemnt‐‐ telescope mirrors (TBD)‐‐ SP cameras, mechanism‐‐ Stokes inversion‐‐ MHD modeling

Need extensive international collaborationand strong supports from you!

27

Thank you28