Displaying report 1-1 of 1.
Reports until 12:01, Thursday 10 August 2017
H1 SEI (CSWG, DetChar, ISC, SUS)
jeffrey.kissel@LIGO.ORG - posted 12:01, Thursday 10 August 2017 (38122)
Test Mass BSC ISI ST2 RX/RY -- Pitch -- Drive (i.e. QUAD Cage) Noise Projection to DELTA L EXTERNAL
J. Kissel, S. Dwyer

Similar to the BSC ISI ST2 X/Y (longitudinal) broad-band excitations taken and projections made two weeks ago (see LHO aLOG 37752), I've processed the RX / RY (pitch) broad-band injections I took a few days ago (see LHO aLOG 38031).

As with longitudinal, All test masses show significant coupling with ambient pitch motion, and more so than in longitudinal especially around 70 Hz. In the first two attachments, I show the projection to DARM, both as a total sum compared with other terms in the noise budget, and as individual optics (including the two worst offenders in longitudinal). Thanks to Sheila for her help making these plots using her "simple" noise budget.
The couplings may be a little underestimated: the coherence between X/Y IN1s and RX/RY IN1s is non-negligible, but it's still small enough (0.1 to 0.2) that adding these noise predictions are incoherent (i.e. adding them in quadrature) is close enough.
Remember that ST2 RX/RY are uncontrolled, but even if they were, the bandwidth could only be 30-40 Hz.

Unfortunately, though these excitations are *loud* as reported by the BSC ISI ST2 GS13s and DARM, the excitations are still too small to be visible in the optical levers* or OSEMs. *Strangely, the coherence between Sus. Point Motion (the projected and calibrated GS13s) and Optical levers goes *down* with the load excitation ON. The second two attachments show the details of the excitations.
But this means meas can't rule out that this *only* motion of the cage.

I'll attach measurement descriptions, calibration functions, and further support material eventually, but the data and templates have been (re)committed to the SeiSVN repo, now with excitation references included: 
/ligo/svncommon/SeiSVN/seismic/BSC-ISI/H1/Common/Data/
    2017-08-06_BSCISI_ST2_BB_RXRY_Injections_ETMX.xml
    2017-08-06_BSCISI_ST2_BB_RXRY_Injections_ETMY.xml
    2017-08-06_BSCISI_ST2_BB_RXRY_Injections_ITMX.xml
    2017-08-06_BSCISI_ST2_BB_RXRY_Injections_ITMY.xml
    2017-08-06_BSCISI_ST2_BB_RXRY_Injections.xml

I also provide a references key text file eventually as well, but I want to get this data up and get on to processing the RZ excitations also taken that day.
Images attached to this report
Displaying report 1-1 of 1.