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Coronas-Photon Project The RT-2 experiment. CORONAS-PHOTON mission is the third satellite of the Russian CORONAS program on the Solar activity observations.
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CORONAS-PHOTON mission is the third satellite of the Russian CORONAS program on the Solar activity observations. The main goal of the CORONAS-PHOTON mission is the study of the Solar flare hard electromagnetic radiation in the wide energy range from Extreme UV up to high energy gamma - radiation (~2000MeV)
Sattelite CORONAS-PHOTON STEP-F TESIS KONUS-RF-anti pressure vessel PHOKA RT-2/GA RT-2/S KONUS-RF N-2M RT-2/G PINGUIN Magnetometer
Orbit and Launcher Satellite CORONAS – PHOTON (METEOR type) Weight <2250kg Launcher: Cyclon-3M Cosmodrome: Plesetsk Orbit: Circular 500-550 km. Inclination 82.5 deg Nominal mission lifetime 3 years Extended 5 years Telemetry 8.2 GHz; Onboard memory 1.0Gbyte Data transmission rate 7.68Mbits/sec Launch: Januray 30, 2009.
Solar activity launch date
NaI(Tl) CsI(Na) PMT Dynode chain 3 detectors (2 phoswich + 1 CZT & CMOS) 1 electronics box
Aschwanden, 07 • 89 solar flares • Eth = 18.0+3.4 keV • = 6.9+0.9 (10 – 20 keV) • = 3.5+1.1 (30 – 50 keV) • Width typically 100 s at high energies • Use Lin et al. 20 keV flux for flare frequency
RT-2 / S & RT-2/CZT Detector Modules
Detector interface Det_1 (P) RT2-S Satellite interface Det_2 (P) RT2-G Processing Electronics Det_3 (CZT) Total Satellite Payload
Design (RT-2CZT) CAM Assembly Collimator Assembly FZP (2 pairs) Detector Housing CMOS CCD instead Of 1 CZT module CZT Detectors
Coded Mask Imaging Concept Multiple pin-hole MASK Mask casts shadow on detector plane Shift of shadow pattern encodes source location Cross correlation of mask pattern with shadow recovers shift and locates sources
Fresnel’s Zone Plate • It is made up of Tungstun of 1 mm thickness and alternate solid and hollow regions with flanges to support the overall structure. • rn = (n)1/2 x r1 where, r1 = radius of innermost disc
CMOS CCD Detector • RadEye 1Premium quality • 25 by 50 mm active area • 5,24,288 pixels (512 x 1024) • Pixel size and intrinsic resolution 48µm (Silicon Photodiodes) • Dark current (at 23°C) – 4000 e-/s • Noise (at 1 fps) – 150 e-/s • Frame rate – 0.01 to 4.5fps • Operating temperature – 0 to 50°C • Dark current doubles approx. every 8°C • Threshold about 150 keV • 30 keV with processing; cooling; low noise
Configuration Concentrate on > 25 keV flares Wide bandwidth required: one Phoswich Change to > 25 keV CZT: Coarse imaging (correct to a few Arcmin to as low an energy threshold as possible) Imaging: A few arcseconds, particularly at high energies RT-2/S: 15 - 120 keV; upto 20000 counts/s; M class flares RT-2/G: 25 - 120 keV; upto 20000 counts/s; X class flares (use Aluminum window) RT-2/CZT: Three CZT detectors; upto 100,000 cts/s CZT1: 10 - 100 keV; CAM; 2 arcminutes CZT2: 25 - 100 keV; CAM. 2 arcminutes CZT3: 25 - 100 keV; FZP 1 arcminutes One CMOS detector: 30 - 100 keV FZP 2 arcseconds
Salient Features … • Fastest time resolution : 0.3 ms (event mode; maximum 2500 counts/s) • Normal mode: 8 channel counts : 10 ms • All spectra : 1 s • Total 6 kbytes in spectral mode • 32 kbytes in event mode (7800 events)
Modes • Debug mode - by command • Solar Quiet mode - by command (100 s; 1 s) • Solar flare mode - onboard intelligence (10 s; 0.1 s) • SAA mode – by good/bad signal • Earth occultation mode – by light/shadow signal
Data management • RT-2/S & G • 1 s count rates + 100 s spectrum throughout. • 100 ms count + 10 s spectrum from 1 hr of flare data (threshold from > 25 keV counts) • 10 ms count + 1 s spectrum from 20 minutes flare data • CZT: 1 s count + 100 s image throughout • CMOS: 1 s count + 100 s image for 1 hr of flare data.