Thursday, August 11, 2016

SAC M4 out!

The RSS collimator doublet came out of the spectrograph & was taken to the clean room for inspection ahead of being cleaned & having its throughput measured.

RSS collimator doublet
The Spherical Aberration Corrector (SAC) M4 mirror in its kinematic "steering wheel" had to be removed to provide access to SAC M5.  M4 turns out to be quite messy too, so it will also get cleaned up before we put everything back together again.  For now though it's safely in its box - after a few pics were taken, the mirror was inverted to protect the optical surface & the lid was bolted closed.

M4 looking up from inside its box
The baffle around the outer edge of M5 was quite awkward to remove, but having done so we could clearly see just how much dust it had kept off the mirror!  We'll do a trial-clean on a small patch outside the clear aperture & then decide whether the coating's in good enough condition for us to proceed.  If that looks ok, we'll remove the central cone baffle & get on with the delicate task of cleaning M5 in situ.

M5 begging to be cleaned

No comments:

Post a Comment