Reports until 10:06, Monday 18 December 2023
H1 CAL
dana.jones@LIGO.ORG - posted 10:06, Monday 18 December 2023 - last comment - 15:12, Wednesday 20 December 2023(74858)
OM2 hot vs. cold broadband measurements

Here's a comparison of Pcal to DeltaL External and GDS Calib Strain broadband measurements with OM2 hot and cold.

File path to DTT template: /ligo/home/dana.jones/Documents/OM2_heating/OM2_hot_v_cold.xml

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dana.jones@LIGO.ORG - 15:12, Wednesday 20 December 2023 (74866)

Dana, Louis

These broadband measurements were taken as part of the regular calibration sweeps when H1 was fully thermalized. To get the measurements, I used this command (for a sample report ID):

pydarm ls -r 20230802T000812Z | grep PCALY2DARM_BB | grep pcal

which returned:

>> pcal: /ligo/groups/cal/H1/reports/20230802T000812Z/PCALY2DARM_BB_20230727T161527Z.xml

Then to get the exact start time of the injection I used:

grep TestTime /ligo/groups/cal/H1/reports/20230802T000812Z/PCALY2DARM_BB_20230727T161527Z.xml

See this link for a list of calibration measurements. To calibrate the Delta L External and Pcal measurements I used the following files found in /ligo/home/dana.jones/Documents/OM2_heating/:

deltal_external_calib_dtt_20230621T211522Z.txt
deltal_external_calib_dtt_20230628T015112Z.txt
deltal_external_calib_dtt_20230716T034950Z.txt
deltal_external_calib_dtt_20230823T213958Z.txt
deltal_external_calib_dtt_20230830T213653Z.txt
deltal_external_calib_dtt_20231027T203619Z.txt

pcal_calib_dtt_20230621T211522Z.txt
pcal_calib_dtt_20230628T015112Z.txt
pcal_calib_dtt_20230716T034950Z.txt
pcal_calib_dtt_20230823T213958Z.txt
pcal_calib_dtt_20230830T213653Z.txt
pcal_calib_dtt_20231027T203619Z.txt

These files were generated using the following two commands (again, for a sample report ID):

pydarm export -r 20230802T000812Z --deltal_external_calib_dtt

and

pydarm export -r 20230802T000812Z --pcal_calib_dtt.

Note: For the most recent curve (23/12/10), I applied the 23/10/27 calibration TF as this was the latest valid one available.

In addition, for GDS_CALIB_STRAIN I applied a gain of 3995 in the Poles/zeros tab to convert to meters (see .xml file).

User note for calibration tab in DTT: Make sure when applying different calibration transfer functions to each curve that you set the start time appropriately—you can’t just use the same time for all of them or the system won’t know which one to choose. For each measurement, set the corresponding calibration start time to, say, 1 day before.

louis.dartez@LIGO.ORG - 15:21, Tuesday 19 December 2023 (74913)
Here's a PCALY-to-GDS_CALIB_STRAIN broadband comparison with the OM2 in the hot state (gold trace, 2023-12-10) and in the cold state (cyan trace, 2023-12-18), see bb_hot_cold_om2.png. Both measurements were taken while the IFO was thermalized. 

Pcal corrections have been applied to PCALY_RX_PD_OUT. 

The two traces don't line up exactly but their differences are down to the percent level. Sheila is pulling up GDS_CALIB_STRAIN spectra from before and after the OM2 cooling for comparison purposes. This plot suggests that she will be able to overlay the two and compare them as long as we're not interested in making any determinations close to ~few percent level.
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