Second Quarter 1995
A first cryostat layout was completed. However, further
work on the optical design resulted in an increase to the beam size
in the spectrograph to avoid having
large prism angles (and therefore larger reflection
losses). This resulted in longer focal length optics.
These have proved more difficult to fold efficiently. The
net result is a larger vacuum jacket.
A preliminary design of the calibration unit was also
produced. Design modifications were made to the IRTF Test Dewar to enable
it to be used for testing arrays, electronics and mechanisms for potential
use in SpeX.