Alexa, Sheila, Dan, Dave O.

Stefan had reported that the original SRM ASC wfs had been oscillating post TCS work (alog 15343). For SRM we had used AS_A_RF36_I as the error signal with a gain of P, Y = 0.3, 1.2. We compared this with REFL_B_RF45_Q error signal, which at one point Livingston had been using, and found this actually appeared to be a better signal. We were able to close the yaw loop with a gain of 4. I did not see any oscillations with this loop closed for about 10 minutes; and it appeared to bring the build up back whenever I misaligned SRM. We tried closing the pitch loop, but have not suceeded yet. We tried a gain of -4 and 4, which caused the loop to oscillate. I reduced the gain of -1, and did not see oscillations, but was not able to recover the build up with an SRM alignment.

For now, we decided to move on and try locking. There is still more work to be done in closing this loop. I will not update the guardian yet.