a coronagraph for the quaff mission: q-cor
DESCRIPTION
A CORONAGRAPH FOR THE QUAFF MISSION: Q-COR. Philippe Lamy Laboratoire d’Astrophysique de Marseille. CORONAGRAPH HERITAGE. LASCO-C2 LASCO-C3 STEREO-KCOR. LASCO C2. Field of View: 1.5 -6 .0 R Sensitivity: 2·10 7 2·10 10 B . LASCO C3. Field of view: 3.7 -30 R - PowerPoint PPT PresentationTRANSCRIPT
Frankfurt - 09 December 2004
A CORONAGRAPH FOR THE QUAFF MISSION: Q-COR
Philippe Lamy
Laboratoire d’Astrophysique de Marseille
Frankfurt - 09 December 2004
CORONAGRAPH HERITAGE
•LASCO-C2•LASCO-C3•STEREO-KCOR
LASCO C2
Field of View: 1.5-6.0 R
Sensitivity: 2·1072·1010 B
Frankfurt - 09 December 2004
Frankfurt - 09 December 2004
LASCO C3Field of view: 3.7-30 R
Sensitivity: 3·1091011 B
Optical parameters of COR2 (STEREO mission)
Frankfurt - 09 December 2004
COR2 optical layout
Frankfurt - 09 December 2004
Frankfurt - 09 December 2004
Optical parameters of Q-COR
Field of View 2-15 Rsun solar elongation (±3.5°)
Spatial Scale 15 arcsec/13 m-pixel
Focal Plane Array 2048 × 2048, 13 m-pixel, 14 bit/pixel
Bandpass 450-600 nm
Exposure times 3 s; 3 exposures required for pB
Synoptic Cadence 1 min.
Maximum Cadence 10 s
Effective Focal Length 185 mm
Stray-light (B) to Disk light (Bo) < 10e-11 B/Bsun
A CORONAGRAPH FOR QUAFF: Q-COR
Subsystem Select Comment
Optical concept KCOR Except O1 (C2) and FOV FOV vs spatial resolution
Optical contact – AR Coated
Structure TBD Rectangular (C2) or tube (KCOR)
Door KCOR-C2 ~ similar design
Ext occulter + AØ C2 Simpler – Superior performances
Light tube C2-KCOR Simple ray tracing
HRM KCOR or C2
O1 C2 Doublet in optical contact-AR Coated
IOCS C2 Not available on KCOR
O2 KCOR
Shutter KCOR Placed in front of O3 (pupil)
Lyot Spot C2
O3 KCOR
Polarizer wheel KCOR Placed in front of CCD
CCD camera ?
Pointing Error Syst C2 If required
S/C Mounting-Pointing ?
Boresighter ?
Frankfurt - 09 December 2004
SPARE PARTS AVAILABLE FROM LASCO-C2• Optical components mounted in their barrels
- lenses- filters + color correctors- polarizers- HRM (heat rejection mirror)
• External occulter + AO• Pointing error system PES• Internal occulter centering system IOCS*• Focusing mecanisms*• Internal calibration system (tungsten lamps)• Shutter*• Filter and polarizer wheels*
CAVEATS- No motors(*)- No rad-hard optical components- No structure- Single set
Frankfurt - 09 December 2004
SOME OUTSTANDING ISSUES
• S/C mounting
• Pointing Strategy
• FOV Clearance
• Radiation damage
• Internal calibration
• Focusing mechanism (air/vacuum)
• Focusing on OE
Frankfurt - 09 December 2004
Q-COR work packages