Reports until 13:52, Wednesday 05 June 2024
H1 ISC
jennifer.wright@LIGO.ORG - posted 13:52, Wednesday 05 June 2024 - last comment - 12:33, Thursday 06 June 2024(78260)
GUARDIAN changes to remove bounce mode of BS

Jennie W, Jenne D, Sheila

 

The other day I designed a new notch to get rid of a bump we had been seeing at 17.75Hz. We think this is the bounce mode of the BS coupling into the MICH loop. The notch for this in LSC-MICH has not been updated since the BRDs were installed I think, and there is no notch for this mode in the ASC-MICH_P and ASC_MICH_Y loops.

 

Changes made to ISC_DRMI.py

Added Bounce-roll notch (FM8) to MICH2 (line 457) in DRMI_LOCKED state and took out line turning on notch at 15Hz (line 456).

#ezca.get_LIGOFilter('LSC-MICH2').switch_on('FM10') # Turn on the BounceRoll FM10 in LSC FM

ezca.get_LIGOFilter('LSC-MICH2').switch_on('FM8') # Turn on the BounceRoll FM8 in LSC FM 05/06/2024 J Wright

 

Added bounce-roll notch to PREP_PRMI_ASC in FM MICH_P and MICH_Y in FM9. These were added to lines 690 and 692.

ezca.get_LIGOFilter('ASC-MICH_P').only_on('INPUT','FM3','FM9','FM10','OUTPUT', 'DECIMATION') #SED increased gain by 20db (removing FM1) Oct 28 2019. added in BR for damped mode at 17Hz 05/06/2024 J Wright
 
ezca.get_LIGOFilter('ASC-MICH_Y').only_on('INPUT','FM3','FM4','FM7','FM9','FM10','OUTPUT', 'DECIMATION')#change LP from LP6 to ELP15 SED DDB March 17 2019, added in BR for damped mode at 17Hz 05/06/2024 J Wright
 

Added these same filters in PREP_DRMI_ASC state in FM MICH_P and MICH_Y in FM9 in lines 920 and 922.

ezca.get_LIGOFilter('ASC-MICH_P').only_on('INPUT', 'FM1','FM3','FM9','FM10','OUTPUT', 'DECIMATION')# added in tuned BR for 17Hz mode J Wright 05/06/2024.
 
ezca.get_LIGOFilter('ASC-MICH_Y').only_on('INPUT', 'FM1','FM3','FM4','FM7','FM9','FM10','OUTPUT', 'DECIMATION')#change LP from LP6 to ELP15 SED DDB March 17 2019, added in tuned BR for 17Hz mode J Wright 05/06/2024.
 
Next time we lock I will see if these remove our noise bump at 17.75 Hz.
 
I loaded the ISC_DRMI guardian when we had just dropped to down.
Comments related to this report
jennifer.wright@LIGO.ORG - 14:11, Wednesday 05 June 2024 (78261)
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Just undid these changes in case they prevent us locking DRMI as we keep falling put from ENGAGE DRMI ASC in ISC_LOCK guardian.

jennifer.wright@LIGO.ORG - 12:33, Thursday 06 June 2024 (78279)
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I turned these filters on when we got to NLN at the start of today's commissioning period. Since they didn't unlock us and seem to possibly make the noise at 17.7Hz better in DARM I have put them back in ISC_DRMI as detailed above and reloaded it. I will post a high resolution spectra next time we get a good lock stetch.