J. Kissel

We're most of the way through turning H1 SUS ETMX into a super actuator of TOP, UIM, and TST actuation stages, so I've installed an over all controller into FM1 of the LSC_DARM filter bank in the H1LSC.txt filter file, called simply "ALSDIFF" (this replaced a "p0.01" integrator). The filter design string is 
zpk([5;5],[0.5;80;80],1,"n")
i.e. two real zeros at 5 [Hz], balanced with two poles at 80 [Hz] to provide a phase boost around 15-20 [Hz], and a boost pole at 0.5 [Hz],
which was the controller used for a design with a 15 [Hz] UGF (see plots from LHO aLOG 11676). Noteably, the DC gain of the filter is unity. We haven't yet installed any of the overall gains, so those will need to be installed and tuned before we *actually* get a UGF of 15 [Hz]. Remember, the design uses both ETMs, and over-estimates the TST drive strength by a factor of 4. But, as long as we install the *measured* gain ratios (again, see LHO aLOG 11676), and are consistent with our overall super-actuator gain, we should be alright.

At this point, our plan is to have what is sent to the suspensions be in units of [um] of desired DARM correction, and we'll have the overall gain of the super actuator be [ct_{TST} / um_{DARMCTRL}], or DAC counts of test mass motion per micron. From LHO aLOG 11676, 
TST: 1.760e-13  [m / ct_{TST}]
     = 1.76e-7 [um / ct_{TST}]
   ==> 5.68e+6 [ct_{TST} / um]