Reports until 15:46, Friday 05 May 2023
H1 ISC (GRD)
elenna.capote@LIGO.ORG - posted 15:46, Friday 05 May 2023 (69358)
Increase DARM offset back in guardian path

We have determined that 40 mA is a better DARM offset to operate at (more in-depth alog coming soon). I have added back in the guardian state "INCREASE_DARM_OFFSET" to the ISC_LOCK guardian. This state will occur between lownoise_length_control and damp_violins_full_power. We will increase the DARM offset to 40 mA in this state. This value is set in lscparams as DCPD_SUM_NLN. For lock acquisition, we will continue to use 20 mA, which is set via DCPD_SUM_TARG in lscparams. We will still have the OMC whitening off in this state, and the OMC_WHITENING state will still check the DCPD counts before turning on the whitening, in case we are in danger of saturation. If the violins are rung up particularly high, we might have to wait a little longer in OMC whitening now before we can proceed to NLN.

The guardian state uses a 5 second ramp time to increase the DARM offset.

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