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cell Up: Positioning
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Mirrors
Use the template from RGOC position collimator 1 (C 
) on the collimator optical axis. Remove R
from its baseplate, remove the alignment post from the telescope end of
the optical bench, and replace it with a perforated alignment target. The
laser beam should now be striking the pole of the front lens of C
. Adjust the position of C
to get the back reflections and interference patterns coincident with the
laser beam at the target. Replace R
and check the separation A
to the pole of C
- this should be 860.5mm. If necessary, adjust by using blocks to allow
the complete collimator baseplate to slide along the collimator axis, and
further clamping blocks and slip gauges to enable controlled adjustment.
Minor adjustment of the longitudinal position of C
can be achieved using the micrometer on C
, but note this has a total range of 2.5mm, so it is best to put this in
the centre of its range, and adjust using the method described above. Remove
the alignment post closest to the laser, and replace it with one of the
perforated targets. . Iterate on checking the separation between R
and C
and the back reflections until both are correct.
Use the same method to position collimator 2 (C 
). The separation between C
and C
should be 227.6mm. Remove C
to do the squaring on. (note: both at RGOC and when aligned at LPO it was
not possible to balance the back reflections and interference patterns
from C
perfectly -- see figure ?? for details. Again, it is necessary to iterate
between separations and back reflections. Clamp the baseplate securely
to the optical bench, and lock all adjusting screws on the kinematic mounts.