Just in case people were confused, although the PRMI + 2 ALS arms were controlled, we weren't able to bring them in to resonance. They were in some unknown off-resonant state.
We can try to calculate the expected recycling gain (ignoring losses in the PRM) following section F.2.1 of my Manifesto:
T_PRM = 5.6%, R_ARMS ~ 98%, G_PRC ~38.
So the full TRX/TRY powers should be G_PRC/T_PRM = 690.
In our stable configuration, we were sitting at TRX/Y powers of ~5-10. Once in awhile we could get a state where the power was saturating the detectors at ~50 and possibly would have gone up to 100, but it was all oscillation at that point. (we've got to find and notch the ETM violin mode frequencies in the ALS feedback servos.
As we move in towards resonance, we have to now consider all of complications of handing off to various error signals and CARM optical spring compensation and RF saturation that have been discussed in Rob's thesis and Lisa's lock acquisition modeling. |