Reports until 15:54, Tuesday 24 April 2018
H1 AOS
jeffrey.bartlett@LIGO.ORG - posted 15:54, Tuesday 24 April 2018 - last comment - 06:01, Wednesday 25 April 2018(41647)
Change PSL Crystal Filters & Adjust Flows 
Peter K., Jeff B. 

   We made several adjustments to the PSL cooling system:

   (1). Changed the Crystal chiller filters inside and outside the enclosure.
   (2). Closed off the chiller bypass to increase the flow from ~11 l/m to 22.5 l/m.
   (3). Opened the throttling valve inside the enclosure to reduce turbulence noise in the manifold.
   (4). Adjusted the Frontend, Power Meter, and 70W Amp flows back to within specs.  

   These adjustments should help reduce the noise from the cooling system in the PSL.
Comments related to this report
peter.king@LIGO.ORG - 06:01, Wednesday 25 April 2018 (41655)PSL
Link 

With the reduced cooling water flows, the output of the 70 W amplifier was reduced by ~4 W.
The pre-modecleaner output over the same time improved a little, or more correctly returned
to its previous.  The uptick at the end of the plot is due to my adjusting the alignment into
the pre-modecleaner with the Picomotors.
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