Reports until 17:28, Wednesday 20 July 2016
H1 ISC (OpsInfo)
sheila.dwyer@LIGO.ORG - posted 17:28, Wednesday 20 July 2016 - last comment - 19:11, Thursday 21 July 2016(28538)
SRM dither alignment loops working

We closed some alignement loops for SRM using a dither and demodulating POP90 this morning.  These loops seem to have a ugf below 100 mHz, so we may want to increase their gain, but they seem to be working well for now.  They come on in the guardian durring the DRMI ASC and leave them on.  They maintain POP 90 (and the ratio of AS90/POP90) at a reasonable level as we go through the CARM offset reduction, engaging the soft loops, and increasing the power. 

We saw a instability that seemed to be a cross  coupling between SRM and SOFT yaw loops, Jenne increased the gain in the soft yaw loops by a factor of 10 which seems to have taken care of the problem and is now in the guardian. 

As long as this keeps working, operators should no longer have to adjust SRM. 

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sheila.dwyer@LIGO.ORG - 19:11, Thursday 21 July 2016 (28575)

Somehow, running this loop durring acquisition was causing an HLTS bounce mode (28 Hz ish, probably PR3) to ring up, which also saturated the quad L2 drives and therefore cause violins to ring up.  We are now using the normal 36 WFS during DRMI, turning them off, and turning on the dither loop in the ENGAGE_SRC_ASC state once we reach full lock.  This donesn't ring anything up.