aLIGO LHO Logbook

H1 SUS (SUS)

leonid.prokhorov@LIGO.ORG - posted 19:06, Tuesday 14 July 2015 - last comment - 17:39, Friday 17 July 2015(19645)

Night OPLEV Charge measurements procedure

I wrote the script for the OPLEV charge measurements which sets most of the settings and easy-to-use. It works for ~ 2.5 hours.
If you are the last person who leaving the LHO in the night - please, run it!

Instructions:
1. Set ISC_Lock state to DOWN
2. Set both ETMs to "ALIGNED" state
3. Align Optical levers (pitch and yaw) for both arms to 0 +/-.5 urad
4. Run the scripts: scripts directory is /ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/Scripts
run the python files: ./ESD_Night_ETMX.py and the second script in another terminal: ./ESD_Night_ETMY.py

If it works, it:
a) In first ~ 30 seconds sets the channels and can warn about troubles with ESD or Alignment. If it happens - check this system and press 
b) During the measurements it should once a second print "Receiving data for GPS second: 1234567" 
c) After all the measurements it should restore all the settings back.

If it gives the errors but still receive some data - let it work.
If it obviously not work, you can try to run it again. If it does not help - please, restore all settings running ./ESD Restore_Settings.py . 

Due to it is first try, today I will be very thankful if you'll check after running the scripts :
1. L3 Lock:
   Bias Voltage - 0
   Offset - green light
   Ramp time - 5s
2. ESD linearization:    Bypass - ON
3. For ETMY:   turned on Hi-voltage driver.
Just in case: scripts modify only this settings.

Comments related to this report

leonid.prokhorov@LIGO.ORG - 17:39, Friday 17 July 2015 (19722)

Link

1. Script was updated to align the optical levers. If you did not align it - script will do it between (a) and (b), i.e. in first minutes. Measurements begin when OPLEV are aligned.
2. If you need to stop the charge measurements, there are two ways. 1.(preferable) Press 'Enter' - it will stop the script not later then in 12 minutes, when all the biases and quadrants will be done for this circle. It will restore all the settings 2. You can break it using Ctrl-C immediately but then you will need to restore ESD settings using ./ESD_Restore_Settings.py or do it manually. Using the second way you also loose and need to manually restore the optical levers offsets for ETMs. 
Note: Main charge measurement scripts set all the settings back to where they find it. If you break it and use ESD_Restore_settings.py - it will set all values to "standard". 
(!) We are talking about change the sign of ESD bias voltage on ETMX. Using ESD_Restore_settings.py will change it to today's value.