I checked the F0 GAS TF when suspension is TWR_FLOAT state but no significant change happens (fig1).
Also, I checked the F0 GAS motion when moving F1 GAS filters and confirmed F0 GAS also moved (fig2).
So, the situation could not be recovered by just moving BF yaw position.
This log shows the health check results of ETMX tower.
I picked up several graphs, which needs to be discussed here, so please see klog37627 to check all transfer functions.
Summary:
Peaks around 1Hz has strange shape when exciting F0 and F1.
BF GAS transfer functions have lower gain than the reference.
Detail:
IPL and IPT transfer functions (fig1 and fig2) are different from the reference but these are due to the filter setting changes due to the FLDACC controls.
Figure 3 and 4 show the transfer functions when changing the filter setting.
Though there are still difference at 30mHz and peaks around 70mHz, they should be fine in terms of the health check because they are due to crossover between ACC and LVDT and coupling between L and T, respectively.
F0 and F1 transfer functions (fig5 and 6) are also different from the reference at the peaks around 1Hz.
According to Takahashi-san, the current suspension position is close to touching the outer flame, and large excitation could cause the suspensions to touch the flame.
So, I measured F0 GAS TF with 10 times smaller excitation (fig7) but the situation didn't change.
In addition, I checked suspension was touching somewhere by moving F1 GAS filters (fig8).
Since there is no motion at F3 and BF GAS, suspension doesn't seem to touch the outer flame.
However, F0 GAS has a strange behaviour due to the change of the F1 GAS filter position, so it is necessary to identify what happens.
BF GAS transfer function has lower gains than the reference at entire frequency bands.
Since the gain at high frequency (frequency region where suspension acts as the free mass) is low, it cannot be explained by just changing the stiffness of the GAS filter.
Since suspension doesn't seem to touch, LVDT calibration and/or actuator efficiency might be reduced.
Other than those differences, TFs are well matched with the references, so they should be fine.
Note:
About IPL and IPT transfer function, manual treatment is now necessary for measuring the TF with correct filter setting.
I will implement it into automeasurement script later but until then, please turn on FM8 of K1:VIS-ETMX_IP_FLDACCINF_H{1,2,3} and FM1 of K1:VIS-ETMX_IP_ACCBLEND_FLDACC{L,T} before starting the script and turn them off after the measurement.
I suspected that the heat-up is wrong according to the data relation between F0 GAS and temp at EYV. I asked Takahashi-san, and we decided to cool down again. I turned off the heater around 8:30. We will check whether we can cool more in EYV.
To adjust F0, I increased the heater power from zero to 900W. Then the temperature increased by 1 C degree. I hope it affected the F0 position to the better status.
This log shows health check results of ETMX payload.
Summary:
TM H1 actuator might have a problem.
Detail:
I ran the automesurement scripts and checked the results of ETMX payload.
Figure 1 - 28 show the graphs of each measurement.
IM EULER DoFs measurements have different results from the reference but they are probably due to the sensor decoupling matrix modifications because there is no difference in TFs from each actuator to each sensor.
TM H1 gain is smaller than the reference by 3dB but I could not confirm the reason and it might be a hardware problem, so it is necessary to check.
Note:
TM health check template didn't work well because we installed switching circuit of ETMX TM coil drivers.
So, I modified the template and then it works well.
This log shows the health check results of ETMX tower.
I picked up several graphs, which needs to be discussed here, so please see klog37627 to check all transfer functions.
Summary:
Peaks around 1Hz has strange shape when exciting F0 and F1.
BF GAS transfer functions have lower gain than the reference.
Detail:
IPL and IPT transfer functions (fig1 and fig2) are different from the reference but these are due to the filter setting changes due to the FLDACC controls.
Figure 3 and 4 show the transfer functions when changing the filter setting.
Though there are still difference at 30mHz and peaks around 70mHz, they should be fine in terms of the health check because they are due to crossover between ACC and LVDT and coupling between L and T, respectively.
F0 and F1 transfer functions (fig5 and 6) are also different from the reference at the peaks around 1Hz.
According to Takahashi-san, the current suspension position is close to touching the outer flame, and large excitation could cause the suspensions to touch the flame.
So, I measured F0 GAS TF with 10 times smaller excitation (fig7) but the situation didn't change.
In addition, I checked suspension was touching somewhere by moving F1 GAS filters (fig8).
Since there is no motion at F3 and BF GAS, suspension doesn't seem to touch the outer flame.
However, F0 GAS has a strange behaviour due to the change of the F1 GAS filter position, so it is necessary to identify what happens.
BF GAS transfer function has lower gains than the reference at entire frequency bands.
Since the gain at high frequency (frequency region where suspension acts as the free mass) is low, it cannot be explained by just changing the stiffness of the GAS filter.
Since suspension doesn't seem to touch, LVDT calibration and/or actuator efficiency might be reduced.
Other than those differences, TFs are well matched with the references, so they should be fine.
Note:
About IPL and IPT transfer function, manual treatment is now necessary for measuring the TF with correct filter setting.
I will implement it into automeasurement script later but until then, please turn on FM8 of K1:VIS-ETMX_IP_FLDACCINF_H{1,2,3} and FM1 of K1:VIS-ETMX_IP_ACCBLEND_FLDACC{L,T} before starting the script and turn them off after the measurement.
I checked the F0 GAS TF when suspension is TWR_FLOAT state but no significant change happens (fig1).
Also, I checked the F0 GAS motion when moving F1 GAS filters and confirmed F0 GAS also moved (fig2).
So, the situation could not be recovered by just moving BF yaw position.
[Kimura, Yasui. H.Sawada and M.Takahashi]
We temporarily closed the side flange on the -Y side of the EXC.
After completing the tightening work, we cleaned up the area around the EXC clean booth.
The cleanup work included removing compressed air cylinders for venting to atmosphere in EXC and flexible piping for the duct-shield cryocooler unit of TMSX side called Xer.
After performing a health check on the EXC suspension, we will tighten the side flange mounting bolts to the specified torque. We then plan to begin evacuating the EXC.
I offloaded the F3 and BF GAS filters with the FRs after closing the EXC.
The health check was performed again after solving the low-coherence problem in BF GAS. Compared with the reference, the coupling from Y to T and R in IM changed. Other TFs look healthy.
ETMX Triangulation Survey — Day 2
A detailed report on the triangulation survey will be added later.
Following the preparation described in [klog 37607](https://klog.icrr.u-tokyo.ac.jp/osl/?r=37607), we carried out a triangulation survey at the X-end using a total station placed at three locations: A, B, and C.
The following points were observed from these three locations for triangulation:
- Reference markers P1 and P2.
- Four corners of the copper housing, circled in red and named C1–C4.
- Four corners of the sapphire nail heads, circled in green and named S1–S4.
In addition, the following points were measured from location C only:
- The HR-side corner of the test-mass ear.
- The HR-side upper corner of the AR-side sapphire nail head bonded to the ear.
Supplements
We aligned the horizontal line of a green laser level with the top surface of the sapphire nail head and made a best-effort adjustment to align it with the center of the P1 marker.
[Moriwaki, Aoumi, Shimode, Hirose]
We checked the existing beam shutter connections in the PSL room and around the OMCDCPD in preparation for the future installation of the Fast Beam Shutter.
- The connection of the beam shutter in the PSL room was checked and confirmed as follows(Fig1):
k1shutter model→ (D-sub 37-pin cable) → Binary In/Out Converter (S1605341, S1910323)→ (BNC cable)→ Shutter Driver (S2314812)→( BNC cable→ Split into two cables: Fig2)→ Shutter
- In addition, since we plan to connect a fast beam shutter to the OMCDCPD in the future, we also checked the circuitry around the OMCDCPD.(Fig3)
OMC DC Driver ["Zsw Ctrl"] (S2416233)→ (D-sub 9-pin cable)→ Binary In/Out Converter (S1910321)["Ch00-07"->"Ch24"]→ (BNC cable)→ OMC Piezo Driver [Shutter Trigger](S1910872)
For the future installation of the Fast Beam Shutter, we are considering disconnecting the D-sub 9-pin cable currently connected between OMC DC Driver ["Zsw Ctrl"] and the Binary In/Out Converter, and connecting the BI/BO of the Fast Beam Shutter directly to OMC DC Driver ["Zsw Ctrl"] instead.
The current connector of the Fast Beam Shutter circuit is a D-sub 25-pin connector, while the output from OMC DC Driver ["Zsw Ctrl"] uses a D-sub 9-pin connector.
Therefore, we are considering changing the connector of the Fast Beam Shutter circuit from D-sub 25-pin to D-sub 9-pin.
Before making this modification, the pin assignments and electrical interface (signal levels, BI/BO configuration, etc.) need to be checked to confirm compatibility with OMC DC Driver ["Zsw Ctrl"].
I offloaded the F0 GAS with the FR.
I offloaded the F0 GAS with the FR.
Though I tried to offload the F0 GAS with the FR, the FR didn't work well. So I changed the setpoint for the F0 GAS from 4250 to 4230 temporarily to avoid saturation.
To test the latest version of the DetChar tools, I checked the Segment files automatically generated using HTCondor and compared them with those generated on k1det1.
The files from August 19 and 20 were not consistent. The likely cause was that the HTCondor job ran at 0, 15, 30, and 45 minutes past each hour, before all data for each 15-minute period were available.
I changed the schedule to 3, 18, 33, and 48 minutes past each hour, following the crontab configuration on k1det1.
I will check the results again after a few days.
Nakagaki, Uchiyama
We successfully extracted log data from the TMP at Y-10. We will send it to the company to investigate the reason for the trouble.
[Kimura]
I found the operational analysis report (in Japanese) for this TMP, which was conducted in October 2021, so I am uploading it.
This TMP had experienced the same anomaly in October 2021 as it did this time.
This work had been postponed because maintenance of the Kashiwa cluster was scheduled after the planned power outage at Kashiwa campus. Though I planned to recover k1nds2 on last Friday, I forgot it and recovered it today.
ETMX Position Survey — Day 1
Detailed measurement data and survey results will be added tomorrow or later.
Today, 5 October, we carried out the first day of the ETMX position survey using a Leica T30 total station, following the preparation described in [klog 37607](https://klog.icrr.u-tokyo.ac.jp/osl/?r=37607).
We plan to take measurements from at least two locations. Today, we completed the measurements from one location.
The following target points were observed:
- Four corners on the near side of the sapphire nail heads, as viewed through the chamber opening.
- Four edge points on the copper clamps securing the nail heads.
- Two reference markers attached to pillars outside the chamber, within the clean booth at the X-end.
We also measured the marker for another measurement location to establish a baseline for the triangulation survey.
[Kimura, Yasui and Uchiyama ]
On the afternoon of Oct. 5, when we checked the fault history using the TMP’s external controller, the attached error log was displayed.
Based on a comparison between the internal clock and my watch, we estimate that this error occurred around 8:30 a.m. on Oct. 2.
On Oct. 6, we plan to extract the operation history stored in the TMP and perform a fault analysis.
(Okabe, Machida, Miyakawa)
We checked the status of the ISS after recovery from the power outage. Due to the outage, the protection circuit for abnormal operation of the main PD power supply had been triggered, cutting off power to the PD. We reset the protection circuit and restored power to the PD, and confirmed that the PD responded to the incident light.
We then set the frequency and output level of the LO supplied to the AOM driver. According to the records from the University of Toyama, the driver should be supplied with an 80 MHz signal at 10 dBm. Since a 1/2 power divider is connected to the LO, this corresponds to an LO setting of 13 dBm, i.e., 1.0 Vrms or 2.825 Vpp into 50 Ω. However, with this setting, approximately 20% of the laser power was lost. We therefore reduced the power to 1/8, i.e., 1 dBm at the driver. With the 1/2 power divider connected to the LO, this corresponds to an LO setting of 4 dBm, i.e., 0.354 Vrms or 1 Vpp into 50 Ω. With this setting, the laser power loss was reduced to approximately 5%, which is consistent with the previous operating condition.
We then brought the ISS Guardian to the Locked state and confirmed that the servo engaged without any problems and that the boost was also turned on.
Regarding the noise performance, we confirmed that both the in-loop and out-of-loop noise levels remained nearly unchanged from their previous levels (Fig.1).
We also measured the OLTF and confirmed that the UGF was approximately 56 kHz, with a phase margin of 21 degrees (Fig.2).
I compared the BF GAS TFs measured in the different executions below.
- Manual execution with the whitening filter OFF in the COILOUTF (Fig. 1): Good coherence.
- Execution using the health check script. The whitening filter was OFF automatically (Fig. 2): Good coherence.
- Manual execution with the whitening filter ON in the COILOUTF (Fig. 3): Bad coherence.
- Result in the first health check on Sep. 27 (Fig. 4): Low coherence.
The COILOUTF output in the third case saturated (over +/- 32768) during the actuation (Fig. 5). The COILOUTF output in the first health check did not saturate (Fig. 6). The low coherence was not due to the saturated actuation.
Preparation for the ETMX Position Survey
Background and purpose
In the NCal calibration, the uncertainty in the center-to-center distance between the NCal and the test mass is one of the major contributors to the overall uncertainty of the NCal signal.
Therefore, while the ETMX chamber is open, it is important to directly survey reference points near the test mass and thereby reduce the uncertainty in the test-mass center position compared with an estimate based only on design drawings and manufacturing tolerances.
Prior to the actual ETMX survey, the surveying instruments were brought to the X-end, and the instrument setup and basic surveying procedure were tested. In particular, an object with a known length was measured to verify the procedure for reconstructing the distance between two points from the measured horizontal angles, vertical angles, and slope distances.
Survey preparation
A Leica T30 total station was brought to the X-end and assembled for the survey.
The horizontal-angle convention of the T30 was confirmed to be Horizontal Right (HR), meaning that the horizontal angle increases clockwise when viewed from above.
A KEK sticker attached to the wall was also sighted and measured to confirm that targets on the wall can be observed with the total station under the conditions expected for the actual survey.
As a basic check of the surveying procedure, both ends of a 1500 mm reference scale were measured. The horizontal angle, vertical angle, and slope distance to each endpoint were recorded, and the three-dimensional distance between the two endpoints was calculated from these measurements.
Check of the electronic level
The T30 has a built-in two-axis electronic level, with the two axes displayed as the L and T axes.
Initially, after leveling the instrument such that the electronic-level readings were close to 0°, the total station was rotated horizontally by 180°. A change in the electronic-level readings was observed after the rotation, with a maximum difference of approximately 0.1°.
This indicated that the electronic level had a zero-point offset.
Based on the 180° reversal measurement, the offsets were estimated to correspond to reference readings of 0.0008° for the L axis and 0.0091° for the T axis. The instrument was then leveled more carefully while taking these offsets into account.
After this adjustment, the total station was rotated again over a wide range of horizontal angles. The electronic-level readings remained nearly constant, with variations suppressed to approximately 0.001°. This confirmed that the instrument remained level as it was rotated.
As an independent check, a laser line level was also used to establish a horizontal reference. The telescope of the total station was rotated over a wide range of horizontal angles, and the projected laser line was observed at several positions located at approximately the same distance from the laser level. At these positions, the laser line was found to coincide closely with the center of the telescope field of view.
The agreement between the laser reference and the telescope line of sight over a wide horizontal-angle range provides an additional confirmation that the total station was properly leveled.
Measurement of the 1500 mm reference scale
The horizontal angle, vertical angle, and slope distance were measured for both ends of the 1500 mm reference scale. The distance between the two endpoints was then reconstructed from these measurements.
The calculated distance was 1502 mm, corresponding to a difference of 2 mm from the nominal length of 1500 mm.
Since this measurement was intended as a preliminary check of the instrument setup and surveying procedure, this result alone does not demonstrate a surveying accuracy of 2 mm. However, it confirms that the overall procedure for reconstructing the three-dimensional distance between two measured points from the angular and distance measurements is functioning as expected.
An accelerometer and a geophone were installed temporary at the X-end to compare with the case when the NCal is installed
The accelerometer was installed on top of the Y-minus NCal pylon, with its Y axis pointing toward the Y-end.
The geophone was installed at the bottom of the pylon, with its N axis pointing toward the Y-end.
The microphone was installed between the NCal pylon and the OpLev.
These data are DQ as following.
Accelerometer
X axis : PEM-PORTABLE_EXC_PACK_EX0_ADC0_DSUB25_OUT_DQ
Y axis : PEM-PORTABLE_EXC_PACK_EX0_ADC0_DSUB26_OUT_DQ
Z axis : PEM-PORTABLE_EXC_PACK_EX0_ADC0_DSUB27_OUT_DQ
Mic
X axis : PEM-PORTABLE_EXC_PACK_EX0_ADC0_DSUB28_OUT_DQ
Geophone
X axis : PEM-PORTABLE_EXA_BOOTH_EXA_BNC5_OUT_DQ
Y axis : PEM-PORTABLE_EXA_BOOTH_EXA_BNC6_OUT_DQ
Z axis : PEM-PORTABLE_EXA_BOOTH_EXA_BNC7_OUT_DQ
