Reports until 15:46, Monday 21 September 2026
H1 SUS (CDS)
oli.patane@LIGO.ORG - posted 15:46, Monday 21 September 2026 (91998)
QOSEM BBSS M1 sat amp whitening modification Timeline and Comparison

 Wanted to compile a table of the whitening changes that we've made to the QOSEM BBSS M1 satamp and how each modification has lowered the time constant. With our current settings, our time constant is 4 seconds, which is much nicer for not saturating compared to the original design, whose time constant was 23 minutes.

  Whitening zpk Compensation zpk LHO implementation LLO implementation Time Constant (s)
Original Design zpk([720e-6],[145e-3],1,"n") zpk([145e-3],[720e-6],1,"n") -- -- ~1400
1st Modification (CIT:1028) zpk([0.0144],[2.89],1,"n") zpk([2.89],[0.0144],1,"n") 2026/07/13 - LHO:91003   70
2nd Modification zpk([0.263],[2.89],1,"n") zpk([2.89],[0.263],1,"n") 2026/09/09 - LHO:91853 2026/07/28 - LLO:82137 4
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