Soon after Type-A suspensions are aligned, both GRX and GRY flashes inside the arm cavities.
So, no serious misalignment happens during the blackout.
Though saturation of the actuators occured, all VIS finaly reached the LOCK_ACQUISITION state after offloading actuators.
Since ITMX F0 GAS and ETMY IP H2 actuators are saturating, they should be offloaded again.
I glued the magnets to the side plates for the IRM damper.
I offloaded the following GAS filters and IPs with the FRs for the recovery from the power outage.
- SRM: F0 GAS, H1 IP
- SR2: F0 GAS
- SR3: F0 GAS
- BS: F0 and F1 GAS
- ITMX: F0, F1, F2, and BF GAS
- ITMY: F0, F1, F2, F3, and BF GAS
- ETMX: F0, F3, and BF GAS
- ETMY: F0, F1, F2, F3, and BF GAS, H1 and H2 IP
- PR3: SF and BF GAS (FR for SF GAS reached SW limit)
The detchar computers (k1det0, k1det1) came back online from the power outage. The regular production of the segment files at k1det1 restarted without issues.
Ushiba, Tanaka
Ushiba-san found that GR beams did not reach the input mirrors even though PR3(SR3) alignment was restored. According to each GR input monitor on POP/POS, GR beams seems to reach to POP/POS table. So I entered the mine and checked the GR laser shutters works or not.
At first, I checked the GRX laser shutter on the POP table. Since the display showed something, the driver itself seemed to be turn on. In this state, I tried to open and close the shutter by medm screen. However, the shutter did not work. Then, I tried to open and close the shutter manually by using the wheel on the driver. I confirmed that I could open and close the shutter manually. So the driver and shutter themselves seems to work. Again, I retried to open and close it by medm screen. Then, I could do so.
Similarly, the GRY shutter could be recovered by the same procedure.
We are not sure of the reason why. One of possibilities is that the current amount to work the shutter is not enough. We used Thorlabs SH1 as the GR shutter and Thorlabs KSC101 as the GR shutter driver. However, KSC101 is designed for a half inch shutter but SH1 is a 1-inch shutter. So we used the driver to work the larger shutter than one that makers expect. Maybe while the driver keep working, we can move the shutter remotely. However, the driver is turned off once. we may need to move the shutter manually once in order to move it remotely .
I paused LSC_LOCK and INTIAL_ALIGNMENT guardian because they change SRM guardian state and would be dangerous during SRM hardware works.
Please do not use these guardians until properly managed their guardian state not to change SRM state or SRM work will be finished.
We opened and actvated interlock systems for GVifi, GVbsx, GVitmx, GVetmx, GVbsy, GVitmy, and GVetmy in the moring on March 6, 2026.
We also opened GVtmsx and stopped TMP of TMSX.
The detail can be found in kagra wiki page.
With several test, we succeeded to take the data and showed the spectrum as shown in Fig.1. (ground motion at the 2nd floor of the Hokubu-kaikan)
So, we can take the ground motion using this portable system in future. (But we need the GPS signal, we cannot take data inside the mine)
If you have interested in the ground motion (ex. atotsu entrance, new laser room, experimental room in your laboratory) please contact to me.
Next step, now we used the AC power supply and DC power supply(pm 15V), but we may possible to change to the battery (12V) operation.
We will make the connector to take the three axis seismometer + microphone (or accelerometer)
Finally, they came back online.
I guess the malfunction of two Sunrise heaters is related to changes in thermal conditions after several years of continuous operation at ~1kW. This means that the inner circuits of heaters are baked at high temperature ( < ~60 °C: this is normal according to the manual) for several years. The circuits inside the heaters might have cracked during the cooling period of the power outage.
We tried to start the BS-C and SR-C Daikin coolers. However, we could not operate the BS-C Daikin cooler in the cooling mode, but only in the air flow mode. We started the IYC-C Daikin cooler, instead. We need a repair for the BS-C Daikin cooler.
Digital system was recovered from the planned power outage.
The recovery of the end stations proceeded largely as scheduled, and at the corner station, thanks to much assistance, the power supply system restoration was completed significantly ahead of schedule. Thanks a lot.
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Issues
VIS-TMSX is unavailable
Though all real-time models are now online, VIS-TMSX cannot be used due to LVDT LO issue reported in klog#36501. VIS-TMSX guardian must be kept in SAFE state (there haven't been any preparation of VIS-TMS control yet, so it's not serious for now)
hyades-1 is still offline
hyades-1 couldn't be launched due to errors on the system disk. Now hyades-0 and hyades-2 are the product servers and hyades-1 which was one of the product server in the past is now just a backup server for emergency cases. So it's not serious. We need more investigation and some additional work for recovering it. Purchasing new disk might be necessary.
Because of the trouble on hyades-1, some servers which mounted the data storage of hyades-1 cannot be launched. I launched them as rescue mode and modified a mount configuration in /etc/fstab. After then, they came back online. Let's ensure to add "nofail" option for NFS mount if the mount point is not essential on that system.
Malfunction of the power supply unit of servers
On k1ioo0 and k1script1, one of the redundant power supply units was beeping. They were connected to the UPS via the AC power strip in the server rack. Because other healthy servers were also connected to the same AC power strip and input power of UPS was shutout by the breaker at the power distribution panel, it may not be related to the power outage itself. Anyway, they were recovered by replacing the power supply units to spare ones.
KImura, Yausi, SawadaH, Uchiyama
We performed recovery works for vacuum system after the blackout.
- We have not opened GVs yet except for GVpr3, GVsrm, GVtmsy.
- Closed GVs: GVifi, GVbsx, GVbsy, GVitmx, GVetmx, GVtmsx, GVitmy, GVetmy, GVommt
- We strted operation of all TMPs except for #10(PRM-PR3) and #26(at TMSY)
- Turned on vacuum gages and Raspberry pies.
We found the vacuum gauge at Xarm21 was out of order.
Some of the vacuum pressure values in the medm overview screen shows empty. We asked DGS members help us.-> finally solved.
Coluor of GVifi in the medm overview screen shows strange (should be red). We will check tomorrow.
After restarting the process, the value reading problem resumed.
We opened and actvated interlock systems for GVifi, GVbsx, GVitmx, GVetmx, GVbsy, GVitmy, and GVetmy in the moring on March 6, 2026.
We also opened GVtmsx and stopped TMP of TMSX.
After restarting the process, the value reading problem resumed.
During the recovery work from the blackout, I noticed that the signal generator used for the LO of the LVDTs of the TMSX-VIS was dead.
When I turned on the generator, it showed "SYSTEM TEST FAILED 001" immediately.
The generator was turned off and the AC cable was removed before the blackout. Still, it is dead now. Probably it was near the end of its lifetime. R.I.P.
As the TMSX-VIS is not actively controlled at this moment, this will not cause any immediate problem.
Yet, we should replace the signal source asap.
I recovered the signal generators for the LVDTs from the power outage. Some commercial SGs have been initialized after the power is off. Their amplitude was set to be the same as the previous state.
Air environment during the power outage
the humidity was kept less than 60%
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With Shingo Hido
We recovered the both Pcals.
There was no issue.
Plots update
- Change plot color: gradient, the center corresponds to 9:00 a.m.
- Scale from Voltage to each physical unit
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About the (5) issue.
We recovered the monitoring system of Xend by changing the AC adpter for the media converter in the morning on March 5, 2026.
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