Robert, Sheila

Similar to what was done in LLO alog 31104 Robert and I made some injections on the end reaction masses while LLO was briefly unlocked last night.  

We only got a good measurement of fringing for ETMX, where we did see a shelf around 45 Hz with a 1 Hz longitudnal excitation.  The RMS velocity of the top mass of the reaction chain was 46nm/s  rms durrig our 1Hz excitation, and about 13 nm/sec rms without any excitation.  Looking at osems on M0 and lower down the chain, it seems like we were driving the test mass at a resonance, so that lower masses were moving more.  At L2 the relative motion between the main and reaction chain was several um/sec, which is 2.5 orders of magnitude larger than the normal velocity at L2, so we don't think this is a problem.  

Times: 17/02/2017 1:42:44 UTC excitation on 1:45:51 quiet time