Kiwamu, Stefan

With the BS L2P and L2Y decoupling in place we were successfully able to hand off a PRY lock to the BS, turning off any PRM and PR2 feed-back.

We needed an output matrix element of -0.05.

The attached open loop gain plot shows a lock on PRM & PR2 in black, the original BS lock in orange, and the final BS lock after adding an additional z30:p100 lead filter.

I then noticed that the BS is still ringing up during lock-acquisition because of an asymmetric saturation in the M2 coils. Adding a low limiter (10000cts) before the f^2 filter fixed the problem, but that was not enough low frequency range once in lock.
Thus I added a z1:p20 filter in the ISCINF filter, with a 2e5cts limiter, followed by a z20:p1 filter in the M3_LOCK filter. This way I can limit high-frequencies earlier, but still have the low frequency range.

With that the PRY was acquiring using only the BS actuation (StripTool trace attached) - success!

Next on the to-do list: power-recycled Michelson.