Caption: A prototype FUSE spectrograph grating being removed from a vacuum
tank in a clean room at Jobin Yvon in France. The FUSE gratings are approximately
a foot square, and contain some 5300 - 5800 lines per millimeter etched
onto its surface. (The exact number changes as a function of position across
each grating, and they are slightly curved, so we can't strictly call them
parallel!) These etchings are what disperse far-UV light into a spectrum
for analysis, and provide the high spectral resolution of the spectrograph.
Placing these complicated etchings onto the curved surface of the grating
was a particularly difficult task carried out by our French colleagues.
It is interesting to note that if the lines on a FUSE grating were
all placed end to end, the resulting line would be over 300 miles long!
(Click on photo to see larger version!) [519 Kb gif]
Caption: A side view of the top end of FUSE during integration at JHU/APL.
This picture shows two of the four FUSE gratings (under red covers) as mounted
in the spectrograph. (May. 1998.)
(Click on photo to see larger version!) [400 Kb gif]