Reports until 17:22, Wednesday 17 August 2016
H1 PSL (PSL)
peter.king@LIGO.ORG - posted 17:22, Wednesday 17 August 2016 (29160)
Water leak in the high power oscillator
This morning Ed asked me to look at some trend plots he had just generated.  Clearly noticeable was a sharp
rise in the humidity and a drop in the flow rates for the heads.  I checked the crystal chiller and its
water level was below minimum and the controller displayed an error informing of such.

    Attached is a picture of the burst hose attached to the head 3 water cooling circuit.  This is the same
connection that failed ~2-1/2 years ago.  I do not recall if it has been adjusted since that time.  Although
care is/was taken to prevent twisting of the hose when the fitting is tightened, it is highly likely that
there was a small twist in the hose that exerted a small shear resulting in the tear seen in the picture.

    Also attached is a picture of the 4f lens for head 4, clearly showing some water droplets on it.

    Apart from the obvious step of replacing the hose, the turbine flow sensor for head 4 will also be
replaced.  The laser will take the better part of a day to dry out - to be on the safe side.  All optical
surfaces and the fibre bundle tips will need to be inspected for cleanliness before any operation of the
high power oscillator is contemplated.
Images attached to this report