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Reports until 11:53, Tuesday 24 March 2015
H1 SEI (ISC)
hugh.radkins@LIGO.ORG - posted 11:53, Tuesday 24 March 2015 (17427)
Dark Mich Lock with BS ST2 Isolation

JimW tweeked the level2 isolation controllers to reduce the gain a few around 100hz.  This morning we got a chance to use them for a time.  The Stage stil can NOT be isolated while the Mich Locks or unlocks without tripping the stage2 watchdog.

The first attachment is an hours trends where I picked dtt start times.  The second attachment is the dtt of MICH_OUT and the ground spectra.  With what looks like a very similar ground motion during the two measurements, there does appear to be reduced output of the MICH Loop with the Stage2 Isolating in the few hz to few 100mhz band.  Good to do similar with more IFO signals when available but it seems this is an improvement.

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