Friday, March 21, 2014

CsI Window Emissivity

The purpose of this experiment was to quantify the emissivity of the CsI window, by comparing spectral settings looking out at the room to the same settings when aimed at a 77K piece of foam.

We obtained 3 hi-med spectral settings at Ames during CD017, just prior to shipment. 

At DAOF, following about 1 week of operations with the CsI window lens uncovered while attached to TAAS, we took the same 3 hi-med spectral setting emissivity data as well as 3 other settings in hi-med and medium modes. 

spec_room  ; spectrum while looking out at the room, no window cover
spec_ln2; spectrum while blocking the window with a LN2 soaked sponge
spec_dark; spectrum taken with lens wheel mirror in place

Assuming that the room has an emissivity of 1.0, the window emissivity is:

emissivity=(spec_ln2-spec_dark)/(spec_room-spec_dark)

more description here:
http://codgermmck.blogspot.com/2014/01/emissivity-of-krs5-window-in-cd014.html





At NASA Ames and DAOF:

OCLI Q 1173 cm-1; 8.52 um
high-med, [0] - [2] ; 50.329 deg, 4 egos, FT=1s,  slit 4 x 5-pix dash
500<DN<4000
emissivity_Ames= 2.7 %  (large uncertainty due to echelle movement)
emissivity_DAOF= 1.6 %

BP14100 729.4 cm-1, 13.71 um
high-med, [0] - [2] ; 55.935 deg, 100 egos, FT=1s, slit 4 x 5-pix dash
500<DN<4000
emissivity_Ames= 2.0 %
emissivity_DAOF= 1.9 %

Soifer 415.4 cm-1, 24.07 um
high-med, [0] - [2] ; 46.265 deg, 6 egos, FT=1s, slit 4 x 5-pix dash
emissivity_Ames= 4.1 %
emissivity_DAOF= 3.9 %


Other settings at DAOF:

N04679 2142.5 cm-1; 4.67 um
medium, [0] - [2] ; 50.621 deg, 100 egos, FT=1s,  slit 7 x 44 deg arc
emissivity_DAOF= 2.2 %

OCLI Q 1150 cm-1; 8.77 um
high-med, [0] - [2] ; 52.502 deg, 4 egos, FT=1s,  slit 4 x 5-pix dash
emissivity_DAOF= 1.7 %

OCLI Q 1150 cm-1; 8.77 um
medium, [0] - [2] ; 52.502 deg, 4 egos, FT=1s (256 rows),  slit 1 x 44 deg arc
emissivity_DAOF= 1.7 %

OCLI O 950 cm-1; 10.53 um
high-med, [0] - [2] ; 52.502 deg, 4 egos, FT=1s,  slit 4 x 5-pix dash
emissivity_DAOF= 2.2 %

OCLI O 950 cm-1; 10.53 um
medium, [0] - [2] ; 52.502 deg, 4 egos, FT=1s (256 rows),  slit 1 x 44 deg arc
emissivity_DAOF= 2.2 %

 

 

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