Reports until 14:29, Monday 17 November 2014
H1 SUS
betsy.weaver@LIGO.ORG - posted 14:29, Monday 17 November 2014 - last comment - 14:08, Wednesday 19 November 2014(15107)
3IFO QUAD Q7 Phase 1 testing

A second round of testing on the all-metal 3IFO QUAD unit Q7 is attached.  After we saw a few cross coupling terms and struggled with coherence in the prior measurement set, we made a few adjustments to the QUAD mechanics.  However, readjusting the lacing cabling and retuning the sensor mounting tablecloth seemed to not help much.  There is still L and R bleeding into P on the reaction chain.  We were able to improve the coherence by building a fort around the test stand however.  The main chain looks to be in pretty good shape though.

 

The first attachement below is of Q7 with damping on and off.

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Comments related to this report
betsy.weaver@LIGO.ORG - 14:31, Monday 17 November 2014 (15110)

The attachment below is of the Q7 (pink traces) undamped TFs compared to the 3IFO Q6 and Q8 units.

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travis.sadecki@LIGO.ORG - 11:04, Tuesday 18 November 2014 (15124)

Screenshots of damping filters for DC offset diagnosis.

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travis.sadecki@LIGO.ORG - 14:08, Wednesday 19 November 2014 (15165)

Spectra for all stages of Q7 attached.  Note that the L1 and L2 stage OSEMs are not aligned and centered.

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