J. Kissel, C. Vorvick, B. Weaver

In prep for closeout of HAM4 after swapping out the SR2 Scrapper Baffle (see LHO aLOG 41768), Cheryl and Betsy remeasured the standard suite of SR2 top-mass transfer functions, and I took a set of ASDs for all the OSEMs hunting for ground loops.

Transfer functions reveal the dynamics are still free-and-clear (even with the large Yaw offset needed to steer the SR3 beam to SR2, as has been needed after the Sep-Dec 2017 incursion), and ASDs suggest that there are no ground-loops on the suspension electronics.

Team SUS is GO for HAM4 door closure.

Raw data lives here:
/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM1/Data
2018-05-02_1655_H1SUSSR2_M1_WhiteNoise_L_0p01to50Hz.xml
2018-05-02_1655_H1SUSSR2_M1_WhiteNoise_P_0p01to50Hz.xml
2018-05-02_1655_H1SUSSR2_M1_WhiteNoise_R_0p01to50Hz.xml
2018-05-02_1655_H1SUSSR2_M1_WhiteNoise_T_0p01to50Hz.xml
2018-05-02_1655_H1SUSSR2_M1_WhiteNoise_V_0p01to50Hz.xml
2018-05-02_1655_H1SUSSR2_M1_WhiteNoise_Y_0p01to50Hz.xml

/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/Common/Data/
2018-05-02_H1SUSSR2_All_OSEM_ASDs.xml


The .pdf attachments are the standard transfer function results. 

The image (.png) attachments show SR2's OSEM ASDs compared against the respective stage's expected sensor noise. Also shown is MC3's for comparison. 
In these, we see that -- although there is a hump in all OSEMs above 1 kHz that deviates from our expected sensor noise, MC3's results confirm my suspicion that this is a common feature to all OSEMs read out by UK satellite amplifiers.