swd 2005, taormina, jun,19-26 an euv imaging detector of space solar telescope qian song, binxun ye,...

SWD 2005, Taormina, Jun,19-26

An EUV Imaging Detector of Space SolaAn EUV Imaging Detector of Space Solar Telescoper Telescope

Qian Song, Binxun Ye, Zhaowang ZhaoQian Song, Binxun Ye, Zhaowang Zhao

National Astronomical Observatories, ChinaNational Astronomical Observatories, ChinaChinese Academy of SciencesChinese Academy of Sciences


Introduction of SSTIntroduction of SST

The Space Solar Telescope,

the first space astronomy program in China


SatelliteSatellite

Solar synchronous circular orbit

Orbit height: 735 km

Inclination: 98.3°

Period: 99.3 min

Attitude: accuracy ±6", stability ±3"/s

Weight: 2 ton

Lifetime: 3 years

Launch: LM-4B


Payloads

• MOT• EUT• HWT• WBS• SIR


Main optical telescop, MOTMain optical telescop, MOT

Resolution 0.1‘

FOV 2.8'×1.5‘

Polarization Accu.

2×10 –4

with a 2-D polarizing spectrograph, working in 8 channels simultaneously


PayloadsPayloads

•HWT: a Hα and white light telescope, whole sun viewing

resolution 1 , FOV 0.7°×0.7°

• WBS: a wide band spectrometer,

investigating high energy flare process on -ray, hard & soft x-ray

• SIR: solar and interplanetary radiospectrometer, 1-60GHz

nonthermal electron populations


EUT EUT

Based on the EUVSAT proposal. Consists of four normal incidence telescopes mounted in a vacuum vessel, which should overlap, be well aligned and synchronized with each other and with the images of the MOT.

Field of view 7’×7’

Resolution 0.8”

Wave length 12.8, 17.1, 19.5, 30.4 nm (subject to change)

Focal length 7.04 m

Distance between Mirrors 1.4 m

Primary Mirror 120 mm

Secondary mirror 48 mm


EUT structureEUT structure


EUT Detector: requirementsEUT Detector: requirements

To achieve highest sensitivity, a combination of a phosphor screen, an image intensifier and a CCD is proposed. This not only improves the sensitivity for low intensity scenes, but as a bonus it provides an electronic shutter as well, one with no moving part.

2048×2048 format At least 12 bit dynamic range between CCD readout noise a

nd full well capacity Spacial resolution should match the telescope’s, 0.8”, or 27.

3μ, 36.6 lp/mm


EUT Detector: StructureEUT Detector: Structure

In order to achieve high sensitivity, an image intensifier is used

A phosphor screen is needed to converse EUV photons to visible.

A CCD imager is to be used with format changing optics (fiber optic taper)


Phosphor’s response on EUVPhosphor’s response on EUV

50 100 150 200 250 300

0.00E+000

5.00E-010

1.00E-009

1.50E-009

2.00E-009

2.50E-009

3.00E-009

3.50E-009

4.00E-009

Cu

rre

nt (A

)

Wavelength (Angstrom)


Phosphor’s output against inputPhosphor’s output against input

60 70 80 90 100 110170

180

190

200

210

220

230

240

250

260

270

100

110

120

130

140

150

160

170 17.1nm1

7.1

nm

's C

urr

en

t (p

A)

Current of Accumulate Circle (mA)

l9.5nm

19

.5n

m's

Cu

rre

nt (p

A)


MCP image intensifier, resolution 57 Lp/mm, gain 8900 cd /m2 /Lx, equivalent background irradiance 0.16 µLx

Optic taper: resolution >102Lp/mm


The front end of the detectorThe front end of the detector


The outlook and inside of the detectorThe outlook and inside of the detector

像增强器

CCD

光锥

荧光屏


5s dark: MCP contribution 800DN 5s dark: MCP contribution 800DN


Test on BSRFTest on BSRF


The image of the 17.1nm beam of BSRFThe image of the 17.1nm beam of BSRF


Resolution test on 17.1nmResolution test on 17.1nm

23µ

19µ13µ

9µ 23µ

19µ13µ

9µ


The intensity distribution of the 19The intensity distribution of the 19μ gridμ grid

1140 1144 1148 1152 1156 1160 1164 1168 1172 1176 1180

14500

15000

15500

16000

16500

17000

17500

19 miron grid C

CD

Rea

dout

(D

N)

Pixel No.


Response of the detector on 17.1nm & 19.5nmResponse of the detector on 17.1nm & 19.5nm

3 4 5 6 7 8 9 10 11 12

4.00E+009

6.00E+009

8.00E+009

1.00E+010

1.20E+010

1.40E+010

1.60E+010

1.80E+010

2.00E+010

Rea

dout

ele

ctro

ns

Incident photon number (108 photons)

G: measurements on 17.1nm Linear Fit of DATA171_G

R: 18 e-/photon

3 4 5 6 7 8 9 10

4.00E+009

6.00E+009

8.00E+009

1.00E+010

1.20E+010

1.40E+010

1.60E+010

1.80E+010

Rea

dout

ele

ctro

nsIncident photon number (108 photons)

H: measurements on 195nm Linear Fit of DATA195_H

R: 21 e-/photon

17.1nm, 18e/photon 19.5nm, 21e/photon


Possible SolutionPossible Solution

Better phosphor screen, MCP, fiber optic taper

Open MCP with CrI or KBr-coated photon cathode+CCD

EUV L3 CCD

Suggestions and comments are very precious for us

SWD 2005, Taormina, Jun,19-26NATIONAL ASTRONOMICAL NATIONAL ASTRONOMICAL

OBSERVATORYOBSERVATORY

swd 2005, taormina, jun,19-26 an euv imaging detector of space solar telescope qian song, binxun ye,...

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