MOSFIRE Study for IRMS
1/24/2011 Updated






MOSFIRE
IRMS
memo


Telescope Aperture
10 m (Keck/Cassegrain)
30 m (TMT/Nasmyth)



Telescope F-ratio
f/14.5
f/15



Plate Scale of Telescope
1.38 arcsec/mm (0.72 mm/arcsec)
300 mm for 6.8'
507 μm for 0.7" slit width
0.45 arcsec/mm (2.22 mm/arcsec)
267 mm for 2'
355 μm for 160 mas slit width



AO
None
NFIRAOS



Pixel Scale
0.18"
0.06"



Detector
H2RG x 1
H2RG x 1



FOV
6.14' x 6.14'
2' x 2'



Pupil Size
125 mm
-



Instrument Rotator
None
Required
Will be coupled w/NFIRAOS interface


OIWFS (On-inst Wave Front Sensors)
Tip-tilt for conpensation of flexure
Required
Feedback to NFIRAOS to monitor tip-tilt(TT), astigmatism, and focus(TTF).


ADC (Atmospheric Dispersion Corrector)
None (on-telescope)
Required (on-instrument)



MOS Method
Cryogenic Configurable Slit Unit (CSU)

~45 remotely configuralbe slit.

Slit width can be adjustable.
CSU?
CSU made by csem (Swiss)


Spectroscopy
Fixed reflective grating used in orders 3,4,5,6 (K,H,J,Y).






Technical Key Points to make IRMS.
MOS method.
Optics.
AO specific mechanisms are required.

Questions
About CSU
Cryogenic performance?
Stray light from the gap of bars? --- Sky obs will be required for this evaluation.
Availability/feasibility of making another (and larger) CSU? Development Time? Cost? Other better solutions?

Others
Optical performance(Image quality)?