[Yuta, Paco]
In summary, we locked FPMI using REFL55_I, REFL55_Q, and AS55_Q. The key to success was to mix POX11_I and POY11_I in the right way to emulate CARM/DARM, and to find out the correct demodulation phase for AS55.
Procedure
- Close PSL shutter and zero offsets in AS55, REFL55, POX11, POY11, and ASDC
- For ASDC run python3 resetOffsets.py -c C1:LSC-ASDC_IN1, otherwise use the zer offsets on I and Q inputs from the RFPD medm screen.
- Lock XARM/YARM using POX/POY to tune demodulation phase.
- Today, the demode phase in POX11 changed to 104.801, and POY11 to -11.256 deg.
- XARM and YARM are used in the following configuration
- INMAT
- 0.5 * POX11_I - 0.5 * POY --> XARM
- 0.5 * POX + 0.5*POY --> YARM
- REFL55_Q --> MICH (** this should be turned on after POX11/POY11)
- LSC Filter gains
- XARM = 0.012
- YARM = 0.012
- MICH = +40 (note the sign flip from last time)
- OUTMAT
- XARM --> 0.5 * ETMX - 0.5 * ETMY
- YARM --> MC2
- MICH --> BS
- UGFs (sanity check)
- XARM (DARM) ~ 100 Hz
- YARM (CARM) ~ 200 Hz
- MICH (MICH) ~ 40 Hz
- Run MICHOpticalGainCalibration.ipynb to see if ASDC vs REFL55_Q looks nice (ellipse in the XY plot), and find any residual offset in REFL55_Q.
- If the plot doesn't look nice in this regard, the IFO needs to be aligned.
- Sensing matrix for CARM/DARM and MICH.
- With the DARM, CARM and MICH lines on, verify the demod error signals look ok both in mag and phase.
- For example, we found that CARM error signals were correctly represented by either 0.5 * POX11_I + 0.5 * POY11_I or 0.5 * REFL55_I.
- Similarly, we found that DARM error signal was correctly represented by either 0.5 * POX11_I - 0.5 * POY11_I or 2.5 * AS55_Q.
- To find this, we minimized CARM content in AS55_Q, as well as CARM content in REFL55_Q.
- We acquired the lock by re-configuring the error point as below:
- INMAT
- 0.5*REFL55_I --> YARM (CARM)
- 2.5 * AS55_Q --> XARM (DARM)
- During the hand-off trials, we repeatedly ran the sensing matrix and UGF measurements while stopping at various intermediate mixed error points to check how the error signal calibrations changed if at all.
- Attachment #1 shows the DARM OLTF using POX/POY (blue), only with CARM handoff (green), and after DARM handoff (red)
- Attachment #2 shows the CARM OLTF using POX/POY (blue), only with CARM handoff (green), and after DARM handoff (red)
- Attachment #3 shows the MICH OLTF using POX/POY (blue), only with CARM handoff (green), and after DARM handoff (red)
- The sensing matrix after handoff is below:
Sensing Matrix with the following demodulation phases
{'AS55': 192.8, 'REFL55': 95.63177865911078, 'POX11': 104.80089727128349, 'POY11': -11.256509422276006}
Sensors DARM CARM MICH
C1:LSC-AS55_I_ERR_DQ 5.09e-02 (89.6761 deg) 2.03e-01 (-114.513 deg) 1.28e-04 (-28.9254 deg)
C1:LSC-AS55_Q_ERR_DQ 4.78e-02 (88.7876 deg) 3.61e-03 (-68.7198 deg) 8.34e-05 (-39.193 deg)
C1:LSC-REFL55_I_ERR_DQ 5.18e-02 (-92.2555 deg) 1.20e+00 (65.2507 deg) 1.15e-04 (-102.027 deg)
C1:LSC-REFL55_Q_ERR_DQ 1.81e-04 (59.0854 deg) 1.09e-02 (-114.716 deg) 1.77e-05 (-23.6485 deg)
C1:LSC-POX11_I_ERR_DQ 8.51e-02 (91.2844 deg) 4.77e-01 (67.1709 deg) 7.97e-05 (-72.5252 deg)
C1:LSC-POX11_Q_ERR_DQ 2.63e-04 (114.584 deg) 1.32e-03 (-113.505 deg) 2.10e-06 (118.146 deg)
C1:LSC-POY11_I_ERR_DQ 1.58e-01 (-88.9295 deg) 6.16e-01 (67.6098 deg) 8.71e-05 (172.73 deg)
C1:LSC-POY11_Q_ERR_DQ 2.89e-04 (-89.1114 deg) 1.09e-03 (70.2784 deg) 3.77e-07 (110.206 deg)
Lock gpstimes:
- [1342220242, 1342220260]
- [1342220420, 1342220890]
- [1342221426, 1342221574]
- [1342222753, 1342223230]
Sensitivity estimate (NANB)
Using diaggui, we look at the AS55_Q error point and the DARM control point (C1:LSC-XARM_OUT). We roughly calibrate the error point using the sensing matrix element and actuation gain at the DARM oscillator freq 4.78e-2 / (10.91e-9 / 307.880^2). The control point is calibrated with a 0.95 Hz SUS pole. Attachment #4 shows the sensitivity estimate. |