SWD 2005, Taormina, Jun,19-26 An EUV Imaging Detector of Space Solar Telescope Qian Song, Binxun Ye, Zhaowang Zhao National Astronomical Observatories, China Chinese Academy of Sciences An EUV Imaging Detector of Space Solar Telescope Qian Song, Binxun Ye, Zhaowang Zhao National Astronomical Observatories, China Chinese Academy of Sciences

SWD 2005, Taormina, Jun,19-26 Introduction of SST The Space Solar Telescope, the first space astronomy program in China

SWD 2005, Taormina, Jun,19-26 Satellite 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 Payloads MOT EUT HWT WBS SIR

SWD 2005, Taormina, Jun,19-26 Main 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 Payloads 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 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 structure

SWD 2005, Taormina, Jun,19-26 EUT 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 and 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: 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 EUV

SWD 2005, Taormina, Jun,19-26 Phosphor ’ s output against input

SWD 2005, Taormina, Jun,19-26 MCP image intensifier, resolution 57 Lp/mm, gain 8900 cd /m 2 /Lx, equivalent background irradiance 0.16 µLx Optic taper: resolution >102Lp/mm

SWD 2005, Taormina, Jun,19-26 The front end of the detector

SWD 2005, Taormina, Jun,19-26 The outlook and inside of the detector

SWD 2005, Taormina, Jun, s dark: MCP contribution 800DN

SWD 2005, Taormina, Jun,19-26 Test on BSRF

SWD 2005, Taormina, Jun,19-26 The image of the 17.1nm beam of BSRF

SWD 2005, Taormina, Jun,19-26 Resolution test on 17.1nm

SWD 2005, Taormina, Jun,19-26 The intensity distribution of the 19μ grid

SWD 2005, Taormina, Jun,19-26 Response of the detector on 17.1nm & 19.5nm 17.1nm, 18e/photon 19.5nm, 21e/photon

SWD 2005, Taormina, Jun,19-26 Possible 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,19-26