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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
SWD 2005, Taormina, Jun,19-26
Introduction of SSTIntroduction of SST
The Space Solar Telescope,
the first space astronomy program in China
SWD 2005, Taormina, Jun,19-26
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
SWD 2005, Taormina, Jun,19-26
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
SWD 2005, Taormina, Jun,19-26
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
SWD 2005, Taormina, Jun,19-26
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
SWD 2005, Taormina, Jun,19-26
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
SWD 2005, Taormina, Jun,19-26
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)
SWD 2005, Taormina, Jun,19-26
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)
SWD 2005, Taormina, Jun,19-26
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)
SWD 2005, Taormina, Jun,19-26
MCP image intensifier, resolution 57 Lp/mm, gain 8900 cd /m2 /Lx, equivalent background irradiance 0.16 µLx
Optic taper: resolution >102Lp/mm
SWD 2005, Taormina, Jun,19-26
The outlook and inside of the detectorThe outlook and inside of the detector
像增强器
CCD
光锥
荧光屏
SWD 2005, Taormina, Jun,19-26
The image of the 17.1nm beam of BSRFThe image of the 17.1nm beam of BSRF
SWD 2005, Taormina, Jun,19-26
Resolution test on 17.1nmResolution test on 17.1nm
23µ
19µ13µ
9µ 23µ
19µ13µ
9µ
SWD 2005, Taormina, Jun,19-26
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.
SWD 2005, Taormina, Jun,19-26
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
SWD 2005, Taormina, Jun,19-26
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
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