Reports until 03:19, Tuesday 27 March 2018
H1 PSL (PSL)
peter.king@LIGO.ORG - posted 03:19, Tuesday 27 March 2018 (41156)
70 W amplifier update
In trying to improve the mode matching into the pre-modecleaner, the alignment through the mode matching
lenses was redone because of a mechanical interference issue with already installed mounts.  With the
lenses in their calculated positions, the beam was still too big for the pre-modecleaner and the visibility
was ~40%.  More beam propagation measurements were taken to check the results from the previous week.
Re-doing the fit and allowing large variations in the amplifier output waist and location, resulted in new
positions for the lenses.  That improved the pre-modecleaner visibility to ~75%.

    At the moment, both the pre-modecleaner and reference cavity are locked but are by no means tweaked up.
I had hoped to be at this stage with less than 10 hours on the amplifier's clock but the alignment and
beam size checks took longer than expected.




 Volker Quetschke / Peter