throughput of a normal incidence spectrometer design in different wavelength ranges luca teriaca max...
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THROUGHPUT OF A NORMAL INCIDENCE SPECTROMETER
DESIGN IN DIFFERENT WAVELENGTH RANGES
Luca TeriacaMax Planck Institut für Sonnensystemforschung
Expected throughput for spatiallyresolved observations.
A = 3.848×10−3 m2, area of the entrance aperture (primary mirror of D=7 cm).
S = 2.56×1010 m2, area of the solar surface imaged over one pixel at perihelion (160×160 km2) by EUS. Equivalent to 1″/pixel angular scale.
r = 3.2912×1010 m, Solar Orbiter–Sun distance at perihelion (0.22 AU).
RP(λ) = Reflectance of the primary SiC mirror.
RG(λ) = Reflectance of the concave variable line-spacing SiC grating (diffraction efficiency times SiC reflectance).
V(λ) = Slit vignetting. Here a 1” wide slit is assumed.
DQE(λ) = Detector quantum efficiency.
L(λ) = Spectral radiance (ph m–2 s–1 sr–1 nm–1). Both average quiet Sun and active region spectra are considered.
Δλ = Spectral resolution element. A value of 0.005 nm is assumed.
LDVRRr
SA
t
NQEGP2
Reflectance of SiC mirrors
Bare and KBr-coated MCPs
Grating diffraction efficiency (SUMER)
λ (nm) efficiency (%) 77 17100 28122 28
efficiencies at higher orders are taken equal to that of the first order
1165 – 1265 Å: Quiet Sun
1165 – 1265 Å: Quiet Sun
1165 – 1265 Å: Quiet Sun
1165 – 1265 Å: Active Region
1165 – 1265 Å: Active Region
1165 – 1265 Å: Active Region
950 – 1050 Å: Quiet Sun
C III
H I Ly γ H I Ly β O VI
Si XII Si XII
950 – 1050 Å: Quiet Sun
C III
H I Ly γH I Ly β O VI
Si XII Si XII
950 – 1050 Å: Active Region
Fe XVI
Si XII Si XII
950 – 1050 Å: Active Region
Fe XVI
Si XII Si XII
700 – 800 Å: Quiet Sun
O III O II O V Ne VIII O IV
N IV S V
Mg IX
700 – 800 Å: Quiet Sun
O III O II O V Ne VIII O IV
N IV S V
Mg IX
700 – 800 Å: Active Region
O III O II O V Ne VIII O IV
N IV S V
Fe XVI Mg IX
700 – 800 Å: Active Region
O III O II O V Ne VIII O IV
N IV S V
Fe XVI Mg IX
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