milano 06.03.09. single step d=400mm, f=40°diag from a message of levacher about next step thermal...
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MILANO 06.03.09
Single step D=400mm, f=40°Diag
From a message of Levacher about ‘next step thermal analysis’ for the baffle can be allocated a space of 400x400mm
Assuming Max Db=400mm FoV (Diag)=40° Dl=200mm
We can have Lb~250 (corresponding to max 50° offaxis,enough for Sun with K=0.5)
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
SS400mm with vanes
Vanes are used so to ensure that the entrance of the system cannot see parts of the baffle directly illuminated by the offaxis source
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
SS400MM Vanes 100% Lambertian R5%
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
IN :5E-1WOUT :1.8E-5WR=3.6E-5
Weights
Element Weight(g)
Tube 510
Front 18
Edge1 25
Edge2 36
Edge3 49
Edge4 66
Edge5 87
Edge6 109
Edge7 132
Back 153
TOTAL 1184
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Aluminium (2.7 g/cm3)0.6mm thickness
Edges
If vane edges are plane greater contributor
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Power=4.66E-6W Power=1.27E-5W
Edges
Beveled Edges, bevel oriented toward outside for the first vanes, toward inside for the others (turning point: when is impossible to light the bevel directly)
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Power=4.9E-6W
Baffle width variation (radius) (length fixed 250mm)
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Both Sizes Variation
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Complete TOU
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Lenses Front / back : no scattering AR 1% ideal Side: scatter 4% reflect 1% (No TIR)
Mountings (Baffle, vanes, stop, telescope tube, lens diaphgrams) Scatter 4% reflect 1%
CCD reflect 5% Baffle dimensions: 440dia - 250length
Weights
Element Weight(g)
Tube 561
Front 25
Edge1 34
Edge2 46
Edge3 61
Edge4 80
Edge5 102
Edge6 126
Edge7 150
Edge8 174
Back 176
TOTAL 1535
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Aluminium (2.7 g/cm3)0.6mm thickness
PST
PST= Point source transmission = detector irradiance/entrance pupil irradiance (for a point source) Irradiance= power/surface Sometime defined in slight different
ways (using power or using system aperture)
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
PST
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
25 deg ‘bump’
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Cut (and painted) last lens
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
NOISE AND SUN
From PDR Noise(ph)/ Noise(b)>3 Count(ph)/ Count(b)>9 Based on a 9 pxs psf, 40 tel phot noise 27ppm/h, G0 star
of mv=11.15 (ReferenceStar) To be budgeted beetwen zodiacal light, straylight, hot
spots, thermal noise Count(ph) is the total photon count form RS (PhRS) or
per pixel (9 pixels) photon count (PhRS/9) (Count(ph)=PhRS or count(ph)=PhRS/9)?
SUN mv=-26.75 G2 Flux ratio F(Sun)/F(RS)=~10^15 approx photon count
same ratioPhSUN=1E15*PhRS PST(50°)<1E-9 – 1E-10 For us PST(50°) ~ 1E-6 – 1E-7 SUNSHIELD!!!
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Ghosts
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
0°
10°
15°
Full detector P=6.44E-2
100x100 pxls P=6.39E-2
Issuses/Future work
TOU mechanical model SunShield Model (Zodiacal light, Out of FoV stars) Sky Model (other sources) Materials and paintings …
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
SQUARED?
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
30°cut buffle
30°cut buffle
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania
Milano, 6.3.9 Matteo Munari Salvo Scuderi - INAF OACatania