Abstract:

IFO was recovered and can reach OBSERVATION state.

What I did:

1. Adding a gain of factor 2 for ETMX_NBDAMP_L3 filter to stop oscillation around 5Hz.
2. Adding a gain of factor 2 for ETMX_NBDAMP_{L,T}1 to stop oscillation around 2.2 Hz.
3. Performing initial alingment of XARM and PRMI to recover the IFO alignment.

Note:

I'm not so sure the change of gains of ETMX_NBDAMP_{L,T}1 during the lock acquisition.
So, if the lock acquisition is not stable with the current condition, it is necessary to turn on gains of 0.5 after reaching PRFPMI_RF_LOCKED state and turn off when IFO lose lock.

Before PRM was aligned, the ETMX GR resonance was lost suddenly during Find IR Resonance.

At present, the IFO cannot reach PRMI 3F locked. During Find IR resonance, ~ a 5Hz peak can be seen in the DARM sensitivity. (Photo.1)

In addition, the earthquake frequency range seismic noise is now increasing, as shown in photo 2. This phenomenon happened when the volcano in Hawaii became active in the past.

I chnaged the LSC lock from Observation to PRFPMI+RF Lock around 9:00 according to the Ushiba-kun's suggestion.

During RF lock, ETMX showed about 5 Hz oscilation, then IFO was unlocked. So we need to mitigate this oscillation.

I took the TCam photos for four mirrors at 9:09~9:37 after Takahashi-san's height adjustment. I will check the image.

During my work, I relaunching PlanetaryImager several times (same as klog).I was wondering that taking and transfering two images was big computer load for the server. If so, I can change the script to take image one by one, not two image at the same time. Anyway, I will check it next week.

During my work, accidentally Miyoki-san requested  PRFPMI_RF_LOCKED state to the LSC_LOCK guardian... This time there was no issue due to this misoperation. Before touching the interferomter, It's better to check the `Commissioning teamup` or the message on ` VIS overview medm` for safety manner. Takahashi-san and I are putting the working message there.

After my work, I requested the PRFPMI_RF_LOCKED to the LSC_LOCK guardian and left the interferometer.

I changed the setpoint for the F2 GAS from 590 to 485 so that the NM V Oplev can be zero.

I changed the setpoint for the F2 GAS from -1568 to -1620 so that the NM V Oplev can be zero.

I changed the setpoint for the F1 GAS from -4820 to -5140 so that the NM V Oplev can be zero. The F1 GAS was offloaded with the FR.

I changed the setpoint for the F1 GAS from -20 to -270 so that the NM V Oplev can be zero.

I took the TCam photos for four mirrors at 8:25~8:30 before Takahashi-san's height adjustment.

6:35 Output temp became 21.8C (cooler stopped cooling)

6:41:Output temp became ~9 C (cooler started cooling)

This phenomenon has sometimes happened in the past. However, this tends to happen on Saturdays, Sundays, and Holidays. It is suspected to relate to some condition changes in the KAGRA site or something.

[Yokozawa, Michimura]

To prepare for 10 W input operations, we added a non-polarizing 50:50 beamsplitter in the IR PD path.
Now the power on TRX IR PD, s-pol PD, p-pol PD and TRX IR CCD camera receive half the power than it used to be.
See attached photo for the updated layout. 2inch BS (Sigma-Koki NPPH(+/-5%)Q-50.8C08-20-W0.5D-1064) was added between RBS1 and RBS3, and a beam dump LB1 was installed in the reflection.
The updated layout is reflected in JGW-T1808962-v21 for both TMSX and TMSY (klog #32181).

[Uchiyama, Ushiba]

We inserted 2-inch BS (NPPH(+/-5%)Q-50.8C08-20-W0.5D-1064) between RBS1 and RBS3 TMSY as shown in fig1 (yellow square).
The ghost beam generated by BS was caught by existing beam dump, which dumps surface reflection of RPD2 (see also fig1).
Figure 2 shows the photos, and BS and beam dump are shown by yellow and blue arrows, respectively.

After that, we centered GR/IR QPDs, and PDs including S/P-pol monitors.
I also added a gain of 2 at FM1 of K1:TM-Y_IR_PDA1 to compensate the power reduction.
Michimura-san and Yokozawa-san performed the similar work at TMSX (32183).

After the work on TMSX/Y, we confirmed PRFPMI can be locked with RF signals, so the work doesn't affect to the lock acquisition.

Temps in the PSL room recovery and PZT voltage for IPs for the IMC injection are shown in the Figure.1

Around UTC0:00 (9:00 JST) today, the GPS got into trouble as shown in Figure 1. Because of this trouble, some applications such as ndscope could not be used.

Michimura-kun guessed

• the leap data cached from IETF page is in /usr/share/zoneinfo/leap-seconds.list, and this file says, "File expires on 28 December 2024".
• Since there is no leap seconds after 2017, and we can just update the expiration timestamp Or update leaps.py (gpstime) with the latest file?

He also found the messages, "ietf.org is no longer serving this file. Use https://data.iana.org/time-zones/data/leap-seconds.list instead." Oshino-kun also said, "Maybe we only need to update tzdata package to update leap-seconds.list file.". However, a careful manner seems to be necessary for the simultaneous update of the GPS file for all servers, and it used to be done by only YamaT-san. 

As an emergency measure, we decided to update the GPS file only in k1ctr0 in the DAB control room to use this server as a remote desktop server from the KAGRA site for today's activities, and Oshino kun performed the attached command for the update. Then ndscope could be active in this server.

Of course, we need the GPS file update for all servers.

IMC alignment was destroyed by the last night earthquake. Ushiba-kun adjusted the IMC alignment in this morning and PRFPMI+RF lock was recovered.

To reduce the DAC noise (basically moving peaks in DAC noise), I modified LSC_LOCK guardian.
Now, 2nd stage dewhitening filters of TM for Type-A suspensions, except for ETMX, are engaged at ENGAGE_WHITENING_FILTERS state (index=1425).

I confirmed IFO can be locked without problems after modifying the guardian.
DAC noise around 68, and 138 Hz were reduced thanks to this modification (fig1).

After tuning the notch filters of Type-A suspensions, I performed the alignment to OMC.
Then, IFO can be locked with DC readout.

So, I plan to keep IFO with requesting OBSERVATION state during New Year Holidays.

I measured the eigenmode frequency of Type-A suspensions and updated the notch filters at MN_DAMP_{L,T}, MN_MNOLDAMP_{R,P,Y}, TM_LOCK_{P,Y}, and ETMX_{IM,MN}_LOCK_L.
Measured data are stored at /users/Commissioning/data/VIS/{ITMX,ETMX,ITMY,ETMY}/eignmode_measurement/.

[Yamaguchi, Nakagaki]

We have changed the operation thresholds for the GV closure devices at the X and Y ends.
Together with yesterday's work, the set values for each device are as follows

• [ETMY]       9.6e-6 Pa
• [ITMY]       6.9e-6 Pa
• [BSY&BSX] 9.4e-6 Pa
• [ITMX]       7.8e-6 Pa
• [ETMX]       2.0e-5 Pa

We located the Magnetic Injection Large Coil (klog30893) to the nominal position (klog31506).

We also tried to make magnetic fields using a function generator (directly, without an amplifier) with 4.1Hz, 20.1Hz, 40.1Hz, and 80.1Hz sine waves.
The permanent magnetometer observed the injected lines.

[Uchikata]
Uchikata-san developped the script to summarize the lockloss count labeled by the SYS_LOCKLOSS guardian. The path is /users/yuzu/lockloss/get_number.sh
The attached image shows the example (Fig).