40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Entry  Thu Sep 10 01:09:20 2015, rana, Update, LSC, Moved LSC sensing matrix notch frequencies NewLSCnotches.png
    Reply  Thu Sep 10 04:23:00 2015, ericq, Update, LSC, Moved LSC sensing matrix notch frequencies DRMI_1F.pdfDRMI_3F.pdf
Message ID: 11589     Entry time: Thu Sep 10 04:23:00 2015     In reply to: 11588
Author: ericq 
Type: Update 
Category: LSC 
Subject: Moved LSC sensing matrix notch frequencies 

Frequencies are:

  • CARM: 309.21 Hz
  • DARM: 307.88 Hz
  • MICH: 311.1 Hz
  • PRCL: 313.31 Hz
  • SRCL: 315.17 Hz

POP110 and POP22 demod angles were adjusted for DRMI lock. 

Last week, I never achieved a fully 1F lock, REFL165 was used for SRCL. Tonight, we created input matrix settings for pure 1F locking, and did some signal mixing to reduce the PRCL to SRCL coupling. The PRCL to MICH coupling was already low, since AS55 is fairly insensitive to PRCL. 

Similarly, for the 3F signals, some signal mixing of REFL33I and REFL165Q was used to reduce the PRCL to MICH coupling. The PRCL to SRCL coupling in REFL165 isn't too bad, so no compensation was done. Interestingly, in this setting, the 3F MICH and SRCL signals agree with the 1F signals on their zero crossing, so no offsets are needed. REFL33 I does need an offset, however, to match the REFL11I PRCL zero crossing. 

The DRMI acquires faster with SRCL set to 165I. Once acquired, the 1F/3F can be made smoothly, and both settings are very stable. The sensing matrix in each setting is consistent with each other. (The PRCL and SRCL lines in AS55 change, but really I shouldn't even plot them, since they're not very coherent). 

For some reason, these show a sign flip relative to last week's measurements. The relative angles are consistent, though. 

Next up is finding the right coefficient for the SRM in the MICH output matrix, when actuating on the BS. 

Attachment 1: DRMI_1F.pdf  72 kB  | Hide | Hide all
DRMI_1F.pdf
Attachment 2: DRMI_3F.pdf  72 kB  | Hide | Hide all
DRMI_3F.pdf
ELOG V3.1.3-