NAOJ GW Elog Logbook 3.2
[Aritomi, Michael]
After opening the gate valves between input/end and arm, we tried to recover FC. We centered the PR reference and first target, but we could see only the scattered light at second target... We checked that the green beam is roughly center of the gate valve between BS/input with the PR reference.
Note: After the gate valve between BS/input is used as PR reference, don't forget to open the gate valve.
In elog2865, it is reported that the RF amplifier (ZHL-2) for AOM stopped outputting. I checked the output of the RF amplifier and confirmed that it is working. I injected the input of 5.5dBm and the output of the amplifier is 23.4dBm, which is reasonable.
I opened the gate valves between input/end and arm. Before I opened the gate valve between input/arm, the pressure of input and arm were 1.2e-6 mbar and 3.7e-8 mbar, respectively. After I opened the gate valve, both of them became 1e-6 mbar. Before I opened the gate valve between end/arm, the pressure of end and arm were 2e-7 mbar and 1.5e-7 mbar, respectively. After I opened the gate valve between end/arm, the pressure of end and arm became 4e-7 mbar and 5.4e-7 mbar, respectively.
[Aritomi, Michael]
We started the evacuation of input/end chambers. After evacuation with a rotary pump, we opened small gate valves close to input/end chambers. The current pressure of end chamber and arm are 3.7e-4 mbar and 3.4e-8 mbar, respectively. The current pressure of input chamber and arm are 4.1e-4 mbar and 3.1e-8 mbar, respectively. We will open small gate valves close to arm, and large gate valves between input/end and arm next week.
Yuhang and Michael
We went through the instructions outlined in T2012111, for installing the Debian 10 operating system on the frontend computer for the central station. As described in 2905, this overrides the previous OS installations on the frontend computer. We have a list of errors/ambiguities in the installation procedure which will be sent to Takahiro Yamamoto.
1.1 OS installation
OS was installed in English. Actually I have tried installing Japanese input packages on my Debian 10 workstation in the past and found it extremely poorly documented, so I didn't even bother with that and will just ask Yamamoto-san.
1.2 Additional packages
No issues. We used 1.0.6 version of cdssoft on the ALIGO Caltech repository. Python and Python3 are called separately, just to let it be known (Python version is 2.7.12, Python3 version is 3.7.3)
1.3 OS settings
As mentioned previously, there was an issue with mounting network locations in the /etc/fstb file. We did not follow through with the rest of the instructions since they all seem to be tied to things appearing in the /users/ directory that was created. I feel like there is also some abiguity in the instructions on where these mount directories should be created. I created them inside /etc/, but maybe I should try again just starting at /.
1.4 Bash settings
No issues. Should mention for clarity that .bashrc is a hidden file located in /home/controls.
1.5 miniconda3 installation
We did not follow through with the last step since it seems the conda command doesn't work. In the first step here, a symbolic link is created between /home/controls and a folder that should be created in /users/DGS..., but nothing is present inside the /users/ folder right now.
1.6 ssh settings
No issues
1.7 NTP settings
No issues
1.8 Vinagre setting
No issues
1.9 Guardian setting
We were not sure where the bugfix is supposed to be applied. But upon looking again there is the blue line at the top that indicates which file is changed, so I will check again before sending my questions to Yamamoto-san.
1.10 Camera settings
The procedure says "camera code itself is old version" but I'm not sure what it is referring to or even if anything is installed.
1.11 SDF settings
I guess the blue line at the top indicates which files should be changed. We haven't tried yet.
1.12 z command
No issues
1.13 Zoom setting
No issues
1.14 Skippy-XD installation
We weren't sure what counts as the "1st PC".
Similar measurement was done in elog2646. In this measurement, the minimum(maximum) CC2 amplitude did not correspond to squeezing(anti-squeezing) quadrature.
Michael and Yuhang
As suggested by Matteo, we took squeezing level and CC2 signal magnitude as a function of CC2 demodulation phase.
They are both normalized, either by shot noise level or CC2 signal without pump.
Fig 1 is squeezing measurements at different CC2 demodulation phase. The phase is changed as linspace(0, 180, 19). It is not understood why sometimes some peaks appear around 5-20kHz.
Fig 2 is squeezing and CC2 signal magnitude as a function of CC2 demodulation phase.
Similar measurement was done in elog2646. In this measurement, the minimum(maximum) CC2 amplitude did not correspond to squeezing(anti-squeezing) quadrature.
Michael and Yuhang
The optical bench was closed and some squeezing measurements are done with different pump power.
The result is attached. Compared with previous characterization, this measurement has more phase noise of 30mrad. It is not understood why phase noise is increased.
Some pictures of the gluing.
After optimizing homodyne balance, alignment and checking parametric gain, I performed some sqz-asqz measurements. The result is shown in the attached figures. The measurement seems not stable enough to match the theoretical prediction curve in Fig.2. New measurements should be done.
6.19dB squeezing was observed
Following on from the previous report, I ignored the Kerberos prompt since it is not used at NAOJ. When it asked me for the hostname and admin password changing server I just left both options blank. After that, the package installation completed.
I am now working on 1.3 of T2012111 (Installation procedure of new workstations (Debian10)). I'm a bit stuck on mounting the folders as shown. The instruction page doesn't seem to match the format accepted by /etc/fstb (figure 1) so I added some spaces that seem consistent with how the mount command works - i.e. device directory filesystem options 0 0. My guess is that the device 10.68.10.100:/opt/rtcds is being mounted to the director /etc/opt/rtcds but maybe I should understand which device this actually is. I get the error shown in figure 2, so something is wrong here.
Takahashi-san glued the magnet of input mirror and released the input/end mirrors. We will start the evacuation of input/end chambers tomorrow.
MZ offset: 4.3
Pump power: 29.4mW
Parametric gain: 504/51.6 = 9.8 (Done by scanning OPO and check BAB transmission. The gain is the ratio of Airy peaks for BAB without pump and BAB with 29.4mW pump. The pump phase was continuously scanned.)
This parametric gain is consistent with old measurement.
During the weekend the first two XY maps.
The maps are attached.
Here the position and average.
Z= 71.075 (center), mean absorption: (42.4 +/- 16.8)
Z= 36.85, mean absorption: (40.8 +/- 9.7)
Additional maps.
Here the position and average.
Z=105.3, mean absorption: (61.6 +/- 13.95)
XZ map, mean absorption: (50.1 +/- 18.1)
YZ map, mean absorption: (56.8 +/- 19.1)
Michael and Yuhang
After pointing out the place where issue appears in elog2916, we followed the suggestion from Pierre and checked the resistor connect through J10.
1. We disconnected three pins of J10.
2. We put resistor meter between these pins. It was found that the resistor between blue and black wires becomes infinity after touching wires.
3. We peeled off the heat shrinkable tubing for black wire at the place of connecting to potentiometer. But no issue was found.
4. We peeled off the heat shrinkable tubing for blue wire at the place of connecting to potentiometer. We found the inner steel part of the wire has broken.
5. We soldered the broken blue wire.
6. We tested OPO locking servo and found it worked again. But we will see if it always work in the next week or so to confirm its recovery.
Michael and Yuhang
We found the new way of fixing lens causes the problem of BAB OPO transmission to drift. This is the second lens we have in the transmission of OPO along the FIS measurement path. So we need to find a new way to fix this lens.
Now we put it on a pedestal pillar. After doing so, a large portion of p-polarization appears. Before removing this p-pol, it composes of ~5% of total power. However, we found that we could convert p-polarization completely to s-polarization by tilting HWP.
Marc, Michael, Yuhang
It was reported in elog2627 that we have problem of OPO locking servo, which works from time to time.
To solve this problem, we contacted Pierre for suggestions. Now, it becomes clear where the problem is from.
Firstly, we need to notice that we should check the OPO locking servo circuit when 'servo output' is just an offset. The test result reported in this elog is in this situation.
We found a triangular wave at J10 Pin3 but not at J10 Pin2. According to Pierre, this is related to the 'amplitude' potentiometer. We will check the impedance between J10 pin1/pin2/pin3. According to Pierre, the total impedance should be about 2k. If not, we need to buy a new one and replace it: Bourns (3590S-2-503L). We should make sure there is no issue for this potentiometer soldering.
Marc, Michael, Yuhang
Today we installed Debian 10 on the Front End PC of the central building (and during this process removed the 2 previously installed os).
Yamamoto-san kindly gave us instructions for this (and also future) installation.
Documentations can be find from these links or inside KAGRA dropbox (folder Subsystem/FKC/TAMA_DGS/Reference documents) :
[1] https://dcc.ligo.org/LIGO-T1600055/public
[2] https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=12111
Marc, Matteo
Today we received 2 25 kg substrates grown by AZTEC and repolished by Sigma Koki.
We applied first contact on one of their surfaces and will apply on their other surfaces later today.
On each mirror barrel there is written 'top' followed by some characters.
We added the mirror number (1 or 2) as well as an arrow pointing towards the 'top' sign.
We will use this as our reference for the top part of the mirror during measurement.
Because new substrates should arrive soon, we decided to pursue our investigation of the annealing of the AZTEC samples by taking several XY measurements with 1 mm step size (instead of 0.25 mm for the previous ones).
The results are reported in the attached entry where only z changes as : 45, 47 49 51 53 56 mm (same order as in picture).
Because of the large step size, it was not so obvious to draw conclusion on the improved/degraded homogeneity with annealing so we decided to start again measurements with 0.5 mm step size.
We are not so sure why the measurement at z = 45 mm (fig 1) has so many values at 0 ppm/cm (the surface should be around 41 mm)
I opened the gate valves between input/end and arm. Before I opened the gate valve between input/arm, the pressure of input and arm were 1.2e-6 mbar and 3.7e-8 mbar, respectively. After I opened the gate valve, both of them became 1e-6 mbar. Before I opened the gate valve between end/arm, the pressure of end and arm were 2e-7 mbar and 1.5e-7 mbar, respectively. After I opened the gate valve between end/arm, the pressure of end and arm became 4e-7 mbar and 5.4e-7 mbar, respectively.