40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 5 of 335  Not logged in ELOG logo
ID Date Author Type Category Subject
  16679   Thu Feb 24 19:26:32 2022 AnchalUpdateGeneralIMC Locking

I think I have aligned the cavity, including MC1 such that we are seeing flashing of fundamental mode and significant transmission sum value as well.However, I'm unable to catch lock following Koji's method in 40m/16673. Autolocker could not catch lock either. Maybe I am doing something wrong, I'll pickup again tomorrow, hopefully the cavity won't drift too much in this time.

  16678   Thu Feb 24 18:05:58 2022 YehonathanUpdateBHDRe-susspension of AS1

{Yehonathan, Anchal, Paco}

Yesterday, Anchal and Paco removed AS1 from the vacuum chamber and moved it into the cleanroom. The suspension wires were cut and the AS1 optic was put on the table.

Two things were noticed:

1. One of the wires was not sitting inside the side block groove (attachment 1)

2. One of the face magnets was grossly tilted (attachment 2). Probably due to uneven polishing of the dumbbell.

We put new wires into the side blocks making sure they sit in their grooves and we removed the tilted magnet. A different, more straight magnet was picked from the remaining spare magnets. The dumbbell and adapter were cleaned from glue residues and a batch of glue was prepared.

In the process of gluing a different magnet was knocked off. We cleaned that magnet too. The 2 magnets were glued on the adapter.

Today I came and saw that the gluing failed completely. One of the magnets was completely away from its socket and the other one wasn't glued at all.

I prepared a new batch of glue and glued the two magnets.

Attachment 1: signal-2022-02-24-173933_003.jpeg
signal-2022-02-24-173933_003.jpeg
Attachment 2: signal-2022-02-24-173933_002.jpeg
signal-2022-02-24-173933_002.jpeg
  16677   Thu Feb 24 14:32:57 2022 AnchalUpdateGeneralMC RFPD DCMON channel got stuck to 0

I found a peculiar issue today. The C1:IOO-MC_RFPD_DCMON remains constantly 0. I wonder if the RFPF output is being read properly. I opened the table and used an oscilloscope to confirm that the DC output from the MC REFL photodiode is coming consistently but our EPICs channel is not reading it. I tried restarting the modbusIOC service but that did not affect anything. I power cycled the acromag chassis while keeping the modbusIOC service off, and then restarted teh modbusIOC service. After this, I saw more channels got stuck and became unresponsive, including the PMC channels. So then I rebooted c1psl without doing anything to the acromaf chasis, and finally things came back online. Everything looks normal to me now but I'm not sure if one of the many channels is not in the right state. Anyways, problem is solved now.

 

  16676   Wed Feb 23 15:08:57 2022 AnchalUpdateGeneralRemoved extra beamsplitter in MC WFS path

As discussed in the meeting, I removed the extra beam splitter that dumps most of the beam going towards WFS photodiodes. This beam splitter needs to be placed back in position before increasing the input power to IMC at nominal level. This is to get sufficient light on the WFS photodiodes so that we can keep IMC locked for more than 3 days. Currently IMC is unlocked and misaligned. I have marked the position of this beam splitter on the table, so putting it back in should be easy. Right now, I'm trying to align the mode cleaner back and start the WFS loops once we get it locked.

  16675   Tue Feb 22 18:47:51 2022 Ian MacMillanUpdateSUSETMY SUS Electronics Replacement

[Ian, Koji]

In preparation for the replacement of the suspension electronics that control the ETMY, I took measurments of the system excluding the CDS System. I took transfer functions from the input to the coil drivers to the output of the OSEMs for each sensor: UL, UR, LL, LR,  and SIDE. These graphs are shown below as well as all data in the compressed file.

We also had to replace the oplev laser power supply down the y-arm. The previous one was not turning on. the leading theory is that it's failure was caused by the power outage. We replaced it with one Koji brought from the fiber display setup.

I also am noting the values for the OSEM DC output

 OSEM  Value
 UL  557
 UR 568
 LR 780
 LL 385
 SIDE 328

In addition the oplev position was:

 OPLEV_POUT  4.871
 OPLEV_YOUT  -0.659
 OPLEV_PERROR  -16.055
 OPLEV_YERROR  -6.667

(KA ed) We only care about PERROR and YERROR (because P/YOUT are servo output)

Edit: corrected DC Output values

Attachment 1: ALL_TF_Graph.pdf
ALL_TF_Graph.pdf ALL_TF_Graph.pdf ALL_TF_Graph.pdf ALL_TF_Graph.pdf ALL_TF_Graph.pdf
Attachment 2: 20220222_SUSElectronicsReplacement.7z
  16674   Wed Feb 16 15:19:41 2022 AnchalUpdateGeneralReconfigured MC reflection path for low power

I reconfigured the MC reflection path for low power. This meant the following changes:

  • Replaced the 10% reflection BS by 98% reflection beam splitter
  • Realigned the BS angle to get maximum on C1:IOO-MC_RFPD_DCMON when cavity is unlocked.
  • Then realigned the steering mirrors for WFS1 and WFS2.
  • I tried to align the light for MC reflection CCD but then I realized that the pickoff for the camera is too low for it to be able to see anything.

Note, even the pick-off for WFS1 and WFS2 is too low I think. The IOO WFS alignment does not work properly for such low levels of light. I tried running the WFS loop for IMC and it just took the cavity out of the lock. So for low power scenario, we would keep the WFS loops OFF.

 

  16673   Tue Feb 15 19:40:02 2022 KojiUpdateGeneralIMC locking

IMC is locking now. There was nothing wrong: just a careful alignment + proper gain adj

=== Primary Alignment ===

- I used WFS error signals as the indicator of the PDH error signals. Checked C1:IOO-WFS1_(I/Q)n_ERR and ended up C1:IOO-WFS1_I4_ERR as it showed the largest PDH error PP.

- Then used MC2 and MC3 to align the IMC by maximizing the PDH error and the MC trans (C1:IOO-MC_TRANS_SUM_ERR)

=== Locking procedure ===

Note that the MC REFL path is still configured for the full power input

- (Only at the beginning) Run scripts/MC/mcdown for initialization / Run scripts/MC/MC2tickleOFF just in case

- Enable IOO-MC-SW1 (MC SERVO switch right after "IN1 Gain (dB)").
- Disable 40:4000 boost
- Increase VCO Gain from -15 to 0
- Jiggle IN1 Gain from low to +31 until the lock is achieved

- As soon as the lock is acquired, enable 40:4000
- Increase VCO Gain to +10
- Turn up "SUPER BOOST" from 0 to 3

=== Lock loss procedure ===

Note that the MC REFL path is still configured for the full power input

- Disable IOO-MC-SW1
- Disable 40:4000 boost
- Reduce VCO Gain 0
- Turn down "SUPER BOOST" to 0

- Then jiggle IN1 Gain again to lock the IMC

=== MC2 spot ===

- It was obvious that the MC2F spot was not on the center of the optic.
- I tried to move the spot on the camera as much as possible, but this did not make the trans beam to the center of the MC end QPD
- I had the impression that the trans beam started to be clipped when the beam was moved towards the end QPD,

We need to reestablish the reasonable/consistent MC2 spot on the mirror, the MC end optics, and the QPD.
We will need to use MC2 dithering and A2L coupling to determine the center of the mirror

But as long as the transmission is maximized, the transmitted beam thru MC1 and MC3 follows the input beam. So we can continue the vent work

The current maximized transmission was ~1300. MC1 refl CCD view was largely off -> The camera path was adjusted.

=== MC2 alignment note ===

During the alignment, I noticed a sudden change of the MC2 alignment. There might be some hysteresis in the MC2 suspension. If you are locking the IMC and noticed significant misalignment, the first thing to try is to touch MC2 alignment.

  16672   Tue Feb 15 19:32:50 2022 KojiUpdateGeneralScheduled power outage recovery - IMC recovery progress

Reduced the IMC power to 100mW

Setup: The power meter was placed right before the final aperture (Attachment 1)

Before the adjustment: Initial position of the HWP was 37.29deg and the input power was 987mW (Attachments 2/3)

After the adjustment: Initial position of the HWP was 74.00deg and the input power was 100mW (Attachments 4/5)

This made the MCREFL reading 0.549.

The MC refl path optics has not been modified.

Attachment 1: PXL_20220216_001731377.jpg
PXL_20220216_001731377.jpg
Attachment 2: Screen_Shot_2022-02-15_at_16.18.16.png
Screen_Shot_2022-02-15_at_16.18.16.png
Attachment 3: PXL_20220216_001727465.jpg
PXL_20220216_001727465.jpg
Attachment 4: Screen_Shot_2022-02-15_at_16.22.16.png
Screen_Shot_2022-02-15_at_16.22.16.png
Attachment 5: PXL_20220216_002229572.jpg
PXL_20220216_002229572.jpg
  16671   Mon Feb 14 21:03:25 2022 KojiUpdateGeneralScheduled power outage recovery

I opened the boxes. Allegra has obvious vent of at least 4 caps. And the power supply did not respond even a paper clip test was performed. https://www.silverstonetek.com/downloads/QA/PSU/PSU-Paper%20Clip-EN.pdf (Paper Clip Test)
=> The mother board and the PSU are dead.

Then Ottavia was also checked. The mother board looked OK, but the PSU did not respond. I quickly opened the PSU and it had a bunch of bulged capacitors in it. => PSU dead

Conclusion: Save the cards/memory etc as much as possible. Migrate the allegra HDD to any other healthy PC or obtain a new used PC from Larry. Otherwise, we just want to buy another WS and copy the disk in it.

 

Attachment 1: PXL_20220215_025325118.jpg
PXL_20220215_025325118.jpg
  16670   Mon Feb 14 18:43:49 2022 PacoSummaryGeneralSOS materials clean room cleared

[Yehonathan, Paco]

We put away most items used / involved in SOS assembly and characterization. Many were stored in the left-most cabinet in the clean area. The OpLev test setup and optics were stored in the upper cabinets above the microscope area, and several screws and other general components were collected in clean bags or wrapped in foil, labeled and put away.

  16669   Mon Feb 14 18:31:50 2022 PacoUpdateGeneralScheduled power outage recovery - IMC recovery progress

[Paco, Anchal, Tega]

We have been realigning the IMC as of last Friday (02/11). Today we made some significant progress (still at high input power), but the IMC autolocker is unable to engage a stable mode lock. We have made some changes to reach this point, including re-centering of the MC1 REFL beam on the ccd, centering of MC2 QPD trans (using flashes), and centering of the MC REFL RFPD beam. The IMC is flashing to peak transmission of > 50% its max (near 14,000 counts average on 2021), and all PDs seem to be working ok... We will keep the PSL shutter closed (especially with high input power) for now.

  16668   Fri Feb 11 17:07:19 2022 AnchalUpdateCDS[Solved] Huge random numbers flowing into ETMX/ETMY ASC PIT/YAW

The autoBurt file for FE already has the C1:ASC-ETMX_PIT_SW2 (and other channels for ETMY, ITMX, ITMY, BS and for YAW) present, and I checked the last snapshot file from Feb 7th, 2022, which has 0 for these channels. So I'm not sure why when FE boots up, it does not follow the switch configuration. Fr safety, I changed all the gains of these filter modules, named like C1:ASC-XXXX_YYY_GAIN (where XXXX is ETMX, ETMY, ITMX, ITMY, or BS , and YYY is PIT or YAW) to 0.0. Now, even if the FE loads with switches in ON configuration, nothing should happen. In future, if we use this model for anything, we can change the gain values which won't be hard to track as the reason why no signal moves forward. Note, the BS connections from this model to BS suspension model do not work.

Quote:

you can hand edit the autoBurt file which the FE uses to set the values after boot up. Just make a python script that amends all of the OFF or ZERO that are needed to make things safe. This would be the autoBurt snap used on boot up only, and not the hourly snaps.

 

Yeah, this is a known issue actually. We go to ASC screen and manually swich off all the outputs after every reboot. We haven't been able to find a way to set default so that when the model comes online, these outputs remain switched off. We should find a way for this.

 

 

  16667   Fri Feb 11 16:09:11 2022 AnchalUpdateGeneralScheduled power outage recovery - Input power increased

We increased the input power to IMC by replacing the 98% transmission BS by a 10% transmission BS on the detection table (reverse of what mentioned in 40m/16408 see attachment 8-9laugh). We then realigned the BS so that MC RFPD is centered. Then we realigned two steering mirrors to get the beam centered on the WFS1 and WFS2 QPD. Then we increased the power of the input beam to get 5.307 reading on the C1:IOO-MC_RFPD_DCMON channel. We did this so that we can align the IMC. Once we have it aligned, we'll go back to low poer for doing chamber work.

Beware, there is about 1W beam on the detection table right now.

 

  16666   Fri Feb 11 12:22:19 2022 ranaUpdateCDS[Solved] Huge random numbers flowing into ETMX/ETMY ASC PIT/YAW

you can hand edit the autoBurt file which the FE uses to set the values after boot up. Just make a python script that amends all of the OFF or ZERO that are needed to make things safe. This would be the autoBurt snap used on boot up only, and not the hourly snaps.

 

Yeah, this is a known issue actually. We go to ASC screen and manually swich off all the outputs after every reboot. We haven't been able to find a way to set default so that when the model comes online, these outputs remain switched off. We should find a way for this.

 

  16665   Fri Feb 11 11:17:00 2022 AnchalUpdateGeneralScheduled power outage recovery

I found that two computers are not powering up in the control room, Ottavia and Allegra. Allegra was important for us as it had the current version of LIGO CDS workstation installed on, providing us with options to use latest packages written by LIGO CDS team. I think the power issue should be resolvable if someone opens it and knows what thye are doing. Do we have any way of getting fuse repairs on such computers? Both these computers are Dell XPS 420.

 

  16664   Fri Feb 11 10:56:38 2022 AnchalUpdateCDS[Solved] Huge random numbers flowing into ETMX/ETMY ASC PIT/YAW

Yeah, this is a known issue actually. We go to ASC screen and manually swich off all the outputs after every reboot. We haven't been able to find a way to set default so that when the model comes online, these outputs remain switched off. We should find a way for this.

 

  16663   Thu Feb 10 21:51:02 2022 KojiUpdateCDS[Solved] Huge random numbers flowing into ETMX/ETMY ASC PIT/YAW

Huge random numbers are flowing into ETMX/ETMY ASC PIT/YAW. Because of this, I could not damp the ETMX/ETMY suspension at the beginning during the recovery from rebooting. (Attachment 1)
By turning off the output of the ASC filters, the mirrors were successfully damped.

Looking at the FE model view of the end RTSs, there were two possibilities: (Attachment 2)

- They are coming from RFM connection
- They are coming from ASXASY

ASX/ASY are not active and I could not see anything producing these numbers. Burtrestore didn't help.

The possibility was something at the other side of the RFM, or corruption of the RFM signal.

- Looking at the RFM model (Attachment 3), the ASC signals are coming from ASS and IOO. The ASS path has the filter module (C1:RFM-ETMX_PIT and etc). This FM is quiet and not guilty.

- Why do we have the RFM from IOO? I went to IOO and found the new ASC (WFS) model is there. I didn't realize the presence of this model. In fact ASC screen showed that these random numbers are flowing into the end SUSs.
So I did burtrestore of c1iooepics. Alas! they are gone.

Now I can go home.

Attachment 1: Screenshot_2022-02-10_21-46-02.png
Screenshot_2022-02-10_21-46-02.png
Attachment 2: Screen_Shot_2022-02-10_at_21.54.21.png
Screen_Shot_2022-02-10_at_21.54.21.png
Attachment 3: Screen_Shot_2022-02-10_at_22.14.23.png
Screen_Shot_2022-02-10_at_22.14.23.png
  16662   Thu Feb 10 21:16:27 2022 KojiSummaryCDSchiara resolv.conf wierdo

During the videomux debug, I noticed that the host name resolving on chiara didn't behave well. Basically I could not login to anything from chiara using host names.

I found that there was no /etc/resolv.conf. Instead, there is /etc/resolvconf directory.

According to my research, live resolv.conf is placed in /run/resolveconf/resolv.conf .

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 192.168.113.20
nameserver 131.215.125.1
nameserver 8.8.8.8

This 113.20 is directing an old "linux1" machine. Too much obsolete. If I modify this file as

# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
#     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
nameserver 192.168.113.104
nameserver 131.215.125.1
nameserver 8.8.8.8
search martian

Then the name resolving became reasonable. However, during rebooting / service resetting / etc, resolvconf -u command is executed and /run/resolveconf/resolv.conf is overridden, as indicated in the file.

I have modified /etc/resolvconf/resolv.conf.d/base to include 192.168.113.104 and search martian . The latter was included but the former did not show up.

FInally I figured out that, after the resolv.conf is constructed from base and head files in /etc/resolvconf/resolv.conf.d/ , NetworkManager overrides the nameserver addresses.
The configuration was found in /etc/NetworkManager/system-connections/Wired\ connection\ 1 .

Here is the modified setting (dns entry was modified)

>sudo cat /etc/NetworkManager/system-connections/Wired\ connection\ 1
[sudo] password for controls:
[802-3-ethernet]
duplex=full
mac-address=68:05:CA:36:4E:B4

[connection]
id=Wired connection 1
uuid=ed177e70-d10e-42be-8165-3bf59f8f199d
type=802-3-ethernet
timestamp=1438810765

[ipv6]
method=auto

[ipv4]
method=manual
dns=192.168.113.104;131.215.125.1;8.8.8.8;
addresses1=192.168.113.104;24;192.168.113.2;

And

>cat /etc/resolvconf/resolv.conf.d/base
search martian
# See Also /etc/NetworkManager/system-connections/Wired\ connection\ 1

So complicated...

  16661   Thu Feb 10 21:10:43 2022 KojiUpdateGeneralVideo Mux setting reset

Now the video matrix is responding correctly and the web interface shows up. (Attachment 1)

Also the video buttons respond as usual. I pushed Locking Template button to bring the setting back to nominal. (Attachment 2)

Attachment 1: Screenshot_2022-02-10_21-11-21.png
Screenshot_2022-02-10_21-11-21.png
Attachment 2: Screenshot_2022-02-10_21-11-54.png
Screenshot_2022-02-10_21-11-54.png
  16660   Thu Feb 10 19:46:37 2022 KojiUpdateGeneralScheduled power outage recovery - Locking mode cleaner(s)

== Assign new IP address to c1sus2 ==

cf: [40m ELOG 16398] [40m ELOG 16396]

- Shutdown c1sus2 (Oh, no. This killed c1lsc/c1sus/c1ioo... This should be taken care of later)

- Confirmed 192.168.113.87 is not alive

- Go to chiara
- Modify /diskless/root/etc/hosts

192.168.113.87  c1sus2 c1sus2.martian

- Modify /etc/dhcp/dhcpd.conf

host c1sus2 {
  hardware ethernet 00:25:90:06:69:C2;
  fixed-address 192.168.113.87;
}

- Modify /var/lib/bind/martian.hosts

c1sus2          A    192.168.113.87
videomux        A    192.168.113.92

- Modify /var/lib/bind/martian.hosts/rev.113.168.192.in-addr.arpa

87            PTR    c1sus2.martian
92            PTR    videomux.martian

- Reload/restart bind9 / dhcpd. Run the following command

sudo service bind9 reload
sudo service isc-dhcp-server restart

- Restart c1sus2 and confirm if the IP address was actually changed

controls@c1sus2:~ 0$ /sbin/ifconfig
eth0      Link encap:Ethernet  HWaddr 00:25:90:06:69:c2
          inet addr:192.168.113.87  Bcast:192.168.113.255  Mask:255.255.255.0
...

== Restart c1lsc / c1sus /c1ioo ==

- Reboot c1lsc/c1sus/c1ioo

- Go to scripts/cds

- Run startC1LSC.sh and follow the instruction

 

  16659   Thu Feb 10 19:03:23 2022 KojiUpdateGeneralScheduled power outage recovery - Locking mode cleaner(s)

I came back to the 40m and started the investigation.

If I ping 192.168.113.92, it responds. But telnet (port 23) was rejected. I somehow tried ssh and it responds! I even could login to the host using usual password. Here is the prompt.

controls@nodus|~> ssh 192.168.113.92
controls@192.168.113.92's password:

...
controls@c1sus2:~ 0$

Oh no...

Looks like c1sus2 and the videomux have the IP address conflict.

Here are the useful ELOG links:

https://nodus.ligo.caltech.edu:8081/40m/4498

https://nodus.ligo.caltech.edu:8081/40m/4529

  16658   Thu Feb 10 17:57:48 2022 AnchalUpdateGeneralScheduled power outage recovery - Locking mode cleaner(s)

Something is wrong with the Video MUX. The system did not turn back on with full functionality. Even though we see the screens as they were before the power shutdown, we have lost control on switching any of the videos. I went to check the wiki page about Video MUX which told be we should be able to see the configuration screen on this link, but the page wasn't opening. I went and removed the power cable and put it back in. That brought back the configuration page. Still, I could not change any of the video feeds however this time, I could see the EPICS channel values (like C1:VID-QUAD1_4) change. I tired to go to the configuration page and change the matrix values from the control tab there. I found out that the matrix was mislabeled and while making the changes, I started seeing blue screen on QUAD1_3 (where MC2T was set before). I set the QUAD1_3 (output 23) to MC2T (input 16), but no change. The EPICS values are also set properly, so I don't understand the reason behind blue screen. The same happened when I tried to use:

~>/opt/rtcds/caltech/c1/scripts/general/videoscripts videoswitch3 QUAD1_3 MC2T

Weirdly, this caused the QUAD1_4 screen to go blue. Running following had no effect:

~>/opt/rtcds/caltech/c1/scripts/general/videoscripts videoswitch3 QUAD1_4 MCR

So, I'm not sure what to do. This really needs to be fixed! I wanted to see teh MC2F camera so that I can align IMC, that was the whole reason for this rabit hole. Help needed.

Attachment 1: PXL_20220211_021509819.jpg
PXL_20220211_021509819.jpg
  16657   Thu Feb 10 15:41:00 2022 AnchalUpdateGeneralScheduled power outage recovery - Locking mode cleaner(s)

I found out that the ESP300 service needs to be run in root mode for it to be able to connect to the USB port of HWP motor controller. While doing this change, I noticed that the channels hosted by c1psl might have a duplication conflict with some other channel hosting computer, because a lot of them show the Warning: "Identical process variable names on multiple servers" which is not good. Someone should look into this conflict.

I added instructions on the power control MEDM screen as it was very non-trivial to use. I have set the power such that the C1:IOO-MC_RFPD_DCMON is 5.6 and this happened at C1:IOO-HWP_POS_SET 2.29.

  16656   Thu Feb 10 14:39:31 2022 KojiSummaryComputersNetwork security issue resolved

[Mike P / Koji / Tega / Anchal]

IMSS/LIGO IT notified us that "ILOM ports" of one of our hosts on the "114" network are open. We tried to shut down obvious machines but could not identify the host in question. So we decided to do a bit more systematic search of the host.

[@Network Rack]
- First of all, we disconnected the optical cables coming to the GC router while the ping is running on the AIRLIGO connected laptop (i.e. outside of the 40m network). This made the ping stopped. This means that the issue was definitely in the 40m.
- Secondly, we started to disconnect (and reconnect) the ethernet cables from the GC router one by one. We found that the ping response stops when the cable named "NODUS" was disconnected.

[@40m IFO lab]
- So we tracked the cable down in the 40m lab. After a while, we identified that the cable was really connected to nodus.

- Nodus was supposed to have one network connection to the martian network since the introduction of the bidirectional NAT router (rather than the old configuration with a single direction NAT router).

- In fact, the cable was connected to "non-networking" port of nodus. (Attachment 1). I guess the cable was connected like this long time, but somehow the ILOM (IPMI) port was activated along with the recent power cycling.

- The cable was disconnected at nodus too. (Attachment 2) And a tape was attached to the port so that we don't connect anything to the port anymore.

Attachment 1: PXL_20220210_220816955.jpg
PXL_20220210_220816955.jpg
Attachment 2: PXL_20220210_220827167.jpg
PXL_20220210_220827167.jpg
  16655   Wed Feb 9 16:43:35 2022 PacoUpdateGeneralScheduled power outage recovery - Locking mode cleaner(s)

[Paco, Anchal]

  • We went in and measured the power after the power splitting HWP at the PSL table. Almost right before the PSL shutter (which was closed), when the PMC was locked we saw ~ 598 mW (!!)
  • Checking back on ESP300, it seems the channel was not enabled even though the right angle was punched in, so it got enabled.
    • No change.
  • The power adjustment MEDM screen is not really working...
  • Going back to the controller, press HOME on the Axis 1 (our HWP) and see it go to zero...
    • Now the power measured is ~ 78 mW.
  • Not sure why the MEDM screen didn't really work (this needs to be fixed later)

We proceeded to align the MC optics because all offsets in MC_ALIGN screen were zeroed. After opening the PSL shutter, we used values from last year as a reference, and try to steadily recover the alignment. The IMC lock remains at large.

  16654   Wed Feb 9 14:34:27 2022 IanSummaryComputer Scripts / ProgramsSUS Plant Plan for New Optics

Restarted the C1sim machine at about 12:30 to help diagnose a network problem. Everything is back up and running

Attachment 1: SummaryMdemScreen.png
SummaryMdemScreen.png
  16653   Wed Feb 9 13:55:05 2022 KojiUpdateGeneralBringing back CDS

Great recovery work and cleaning of the rebooting process.

I'm just curious: Did you observe that the c1sus2 cards have different numbering order than the previous along with the power outage/cycling?

  16652   Wed Feb 9 11:56:24 2022 AnchalUpdateGeneralBringing back CDS

[Anchal, Paco]

Bringing back CDS took a lot of work yesterday. I'm gonna try to summarize the main points here.


mx_start_stop

For some reason, fb1 was not able to mount mx devices automatically on system boot. This was an issue I earlier faced in fb1(clone) too. The fix to this problem is to run the script:

controls@fb1:/opt/mx/sbin/mx_start_stop start

To make this persistent, I've configured a daemon (/etc/systemd/system/mx_start_stop.service) in fb1 to run once on system boot and mount the mx devices as mentioned above. We did not see this issue of later reboots yesterday.


gpstime

Next was the issue of gpstime module out of date on fb1. This issue is also known in the past and requires us to do the following:

controls@fb1:~ 0$ sudo modprobe -r gpstime
controls@fb1:~ 1$ sudo modprobe gpstime

Again, to make this persistent, I've configured a daemon (/etc/systemd/system/re-add-gpstime.service) in fb1 to run the above commands once on system boot. This corrected gpstime automatically and we did not face these problems again.


time synchornization

Later we found that fb1-FE computers, ntp time synchronization was not working and the main reason was that fb1 was unable to access internet. As a rule of thumb, it is always a good idea to try pinging www.google.com on fb1 to ensure that it is connected to internet. The issue had to do with fb1 not being able to find any namespace server. We fixed this issue by reloading bind9 service on chiara a couple of times. We're not really sure why it wasn't working.

~>sudo service bind9 stop
~>sudo service bind9 start
~>sudo service bind9 status
* bind9 is running

After the above, we saw that fb1 ntp server is working fine. You see following output on fb1 when that is the case:

controls@fb1:~ 0$ ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
-table-moral.bnr 110.142.180.39   2 u  399  512  377  195.034  -14.618   0.122
*server1.quickdr .GPS.            1 u   67   64  377  130.483   -1.621   1.077
+ntp2.tecnico.ul 56.99.239.27     2 u  473  512  377  184.648   -0.775   2.231
+schattenbahnhof 129.69.1.153     2 u  365  512  377  144.848    3.841   1.092
 192.168.123.255 .BCST.          16 u    -   64    0    0.000    0.000   0.000

On the FE models, timedatectl should show that NTP synchronized feild is yes. That wasn't happening even after us restarting the systemd-timesyncd service. After this, I just tried restarting all FE computers and it started working.


CDS

We had removed all db9 enabling plugs on the new SOSs beforehand to keep coils off just in case CDS does not come back online properly.

Everything in CDS loaded properly except the c1oaf model which kepy showing 0x2bad status. This meant that some IPC flags are red on c1sus, c1mcs and c1lsc as well. But everything else is green. See attachment 1. I then burtrestroed everything in the /opt/rtcds/caltech/c1/burt/autoburt/snapshots/2022/Feb/4/12:19 directory. This includes the snapshot of c1vac as well that I added on autoburt that day. All burt restore statuses were green OK. I think we are in good state now to start watchdogs on the new SOSs and put back the db9 enabling plugs.


Future work:

When somebody gets time, we should make cutom service files in fb1:/etc/systemd/system/ symbolic links to a repo directory and version control these important services. We should also make sure that their dependencies and startup order is correctly configured. I might have done a half-assed job there since I recently learned how to make unit files. We should do the same on nodus and chiara too. Our hope is that on one glorious day, the lab can be restarted without spending more than 20 min on booting up the computers and network.

 

Attachment 1: Screenshot_2022-02-09_12-11-33.png
Screenshot_2022-02-09_12-11-33.png
  16651   Mon Feb 7 16:53:02 2022 KojiUpdateGeneralScheduled power outage recovery

I went to the X end and found it was warm. Turned out that not all the A/Cs were on. They were turned on now.

Attachment 1: PXL_20220208_001646282.jpg
PXL_20220208_001646282.jpg
Attachment 2: PXL_20220208_001657871.jpg
PXL_20220208_001657871.jpg
  16650   Mon Feb 7 16:14:37 2022 TegaUpdateComputersrealtime system reboot problem

I was looking into plotting temperature sensor data trend and why we currently do not have frame data written to file (on /frames) since Friday, and noticed that the FE models were not running. So I spoke to Anchal about it and he mentioned that we are currently unable to ssh into the FE machines, therefore we have been unable to start the models. I recalled the last time we enountered this problem Koji resolved it on Chiara, so I search the elog for Koji's fix and found it here, https://nodus.ligo.caltech.edu:8081/40m/16310. I followed the procedure and restarted c1sus and c1lsc machine and we are now able to ssh into these machines. Also restarted the remaining FE machines and confirm that can ssh into them. Then to start models, I ssh into each FE machine (c1lsc, c1sus, c1ioo, c1iscex, c1iscey, c1sus2) and ran the command

rtcds start --all

to start all models on the FE machine. This procedure worked for all the FE machines but failed for c1lsc. For some reason after starting the first the IOP model - c1x04, c1lsc and c1ass, the ssh connection to the machine drops. When we try to ssh into c1lsc after this event, we get the following error :  "ssh: connect to host c1lsc port 22: No route to host".  I reset the c1lsc machine and deecided to to start the IOP model for now. I'll wait for Anchal or Paco to resolve this issue.


[Anchal, Tega]

I informed Anchal of the problem and ask if he could take a look. It turn out 9 FE models across 3 FE machines (c1lsc, c1sus, c1ioo) have a certain interdependece that requires careful consideration when starting the FE model. In a nutshell, we need to first start the IOP models in all three FE machines before we start the other models in these machines. So we turned off all the models and shutdown the FE machines mainly bcos of a daq issue, since the DC (data concentrator) indicator was not initialised. Anchal looked around in fb1 to figure out why this was happening and eventually discovered that it was the same as the ms_stream issue encountered earlier in fb1 clone (https://nodus.ligo.caltech.edu:8081/40m/16372). So we restarted fb1 to see if things clear up given that chiara dhcp sever is now working fine. Upon restart of fb1, we use the info in a previous elog that shows if the DAQ network is working or not, r.e. we ran the command

$ /opt/mx/bin/mx_info
MX:fb1:mx_init:querying driver:error 5(errno=2):No MX device entry in /dev.

 The output shows that MX device was not initialiesd during the reboot as can also be seen below.

$ sudo systemctl status daqd_dc -l

● daqd_dc.service - Advanced LIGO RTS daqd data concentrator
   Loaded: loaded (/etc/systemd/system/daqd_dc.service; enabled)
   Active: failed (Result: exit-code) since Mon 2022-02-07 18:02:02 PST; 12min ago
  Process: 606 ExecStart=/usr/bin/daqd_dc_mx -c /opt/rtcds/caltech/c1/target/daqd/daqdrc.dc (code=exited, status=1/FAILURE)
 Main PID: 606 (code=exited, status=1/FAILURE)

Feb 07 18:01:56 fb1 systemd[1]: Starting Advanced LIGO RTS daqd data concentrator...
Feb 07 18:01:56 fb1 systemd[1]: Started Advanced LIGO RTS daqd data concentrator.
Feb 07 18:02:00 fb1 daqd_dc_mx[606]: [Mon Feb  7 18:01:57 2022] Unable to set to nice = -20 -error Unknown error -1
Feb 07 18:02:00 fb1 daqd_dc_mx[606]: Failed to do mx_get_info: MX not initialized.
Feb 07 18:02:00 fb1 daqd_dc_mx[606]: 263596
Feb 07 18:02:02 fb1 systemd[1]: daqd_dc.service: main process exited, code=exited, status=1/FAILURE
Feb 07 18:02:02 fb1 systemd[1]: Unit daqd_dc.service entered failed state.


NOTE: We commented out the line

Restart=always

in the file "/etc/systemd/system/daqd_dc.service" in order to see the error, BUT MUST UNDO THIS AFTER THE PROBLEM IS FIXED!

  16649   Mon Feb 7 15:32:48 2022 YehonathanUpdateGeneralY End laser controller

I went to the Y end. The AUX laser was on Standby. I pushed the Standby button. The laser turned on and there was some green light. However, the controller displayed the message "CABLE?" which according to the manual means that the laser head is powered but there is no control over the laser (e.g. the control cable is disconnected). I turned off the controller and disconnected both the power and control cables. I put them back and turned the controller back on.

I pushed the Standby button, the laser turned on and this time the controller displayed the laserhead's state. I was able to change the current/temperature. The problem seems to be resolved.

  16648   Mon Feb 7 09:00:26 2022 PacoUpdateGeneralScheduled power outage recovery

[Paco]

Started recovering from scheduled (Feb 05) power outage. Basically, time-reversing through this list.


== Office area ==

  • Power martian network switches, WiFi routers on the north-rack.
  • Power windows (CAD) machine on.

== Main network stations ==

  • Power on nodus, try ping (fail).
  • Power on network switches, try ping (success), try ssh controls@nodus.ligo.caltech.edu (success).
  • Power on chiara to serve names for other stations, try ssh chiara (success).
  • Power on fb1, try ping (success), try ssh fb1 (success).
  • Power on paola (xend laptop), viviana (yend laptop), optimus, megatron.

== Control workstations ==

  • Power on zita (success)
  • Power on giada (success), run system upgrade.
  • Power on donatella (success)
  • Power on allegra (fail)  **
  • Power on pianosa (success)
  • Power on rossa (success)
  • From nodus, started elog (success).

== PSL + Vertex instruments ==

  • Turn on newport PD power supplies on PSL table.
  • Turn on TC200 temp controller on (setpoint --> 36.9 C)
  • Turn on two oscilloscopes in PSL table.
  • Turn on PSL (current setpoint --> 2.1 A, other settings seem nominal)
  • Turn on Thorlabs HV pzt supply.
  • Turn on ITMX OpLev / laser instrument AC strip.

== YEND and XEND instruments ==

  • Turn on XEND AUX pump on (current setpoint -->1.984 A)
  • Turn on XEND AUX SHG oven on (setpoint --> 37.1 C) (see green beam)
  • Turn on XEND AUX shutter controller on.
  • Turn on DCPD supply, and OpLev supply AC strip on.
  • Turn on YEND AUX pump on (fail) *
    • With the controller on STDBY, I tried setting up the current but got HD FAULT (or according to the manual this is what the head reports when the diode temperature is too high...)
    • Upon power cycling the controller, even the controller display stopped working... YAUX controller + head died? maybe just the diode? maybe just the controller?
      • I borrowed a spare LW125 controller from the PSL table (Yehonathan pointed me to it) and swapped it in.
      • Got YEND AUX to lase with this controller, so the old controller is busted but at least the laser head is fine.
      • Even saw SHG light. We switched the laser head off to "STDBY" (so it remains warm) and took the faulty controller out of there.
  • Turn on YEND AUX SHG oven on (setpoint -->35.7 C)
  • Turn on YEND AUX shutter controller on.

== YARM Electronic racks ==

== XARM Electronic racks ==

 


* Top priority, this needs to be fixed.

** Non-priority, but to be debugged

  16647   Fri Feb 4 10:21:39 2022 AnchalSummaryGeneralComplete lab shutdown

Please edit this same entry throughout the day for the shutdown elogging.

I took a screenshot of C0VAC_MONITOR.adl to ensure that all pnematic valves are in closed positions:

The status message says "All pnematic valves closed" and the latest error message is about "V7 closed, N2 < 6.50e+01".

I found out that there was no autoburt happening for c1vac channels. I created an autoBurt.req file for the vac.db file and saved one snapshot. I also added the path of this file in autoburt/.requestfilelist . Let's see if autoburting starts by that for this file as well.

With this, I think we can safely shutdown acromag chassis. Hopefully, the relays are configured such that the valves are nominally closed in absence of a control signal. After the chassis is shut down, wwe can shutdown C1VAC by:

sudo shutdown

[Chub, Jordan]

At the 1x8 rack, the following were switched off on their respective front panels:

PTP2 & PTP3 Controller
MKS Gauge controller
PRP Gauge Controller
G2P316a & b Controllers
Sorenson
Serial Device Server
Both UPS's

Powered off from back of unit:

TP1 Controller
Acromag chassis

TP2 and 3 controllers were unplugged from respective power strips (labeled C2 and C3)

C1vac and the laptop at the workstation were shut down

Manual Gate valve was closed

  16646   Fri Feb 4 10:04:47 2022 ChubUpdateGeneraldish soap and clean scrub sponges!

Bought dish soap and scrub sponges today and placed them under the sink with the other dish supplies.

Attachment 1: 40m_supplies.jpg
40m_supplies.jpg
  16645   Thu Feb 3 17:15:23 2022 TegaSummaryComputer Scripts / ProgramsSUS Plant Plan for New Optics

Finally got the SIMPLANT damping to work following Rana's suggestion to try damping one DoF at a time, woo-hoo!

At first, things didn't look good even when we only focus on the POS DoF. I then noticed that the input value (X1:SUS-OPT_PLANT_TM_RESP_1_1_IN1) to the plant was always zero. This was odd bcos it meant the control signal was not making its way to the plant. So I decided to look at the sensor data

(X1:SUS-OPT_PLANT_COIL_IN_UL_OUTPUT, X1:SUS-OPT_PLANT_COIL_IN_UR_OUTPUT, X1:SUS-OPT_PLANT_COIL_IN_LR_OUTPUT, X1:SUS-OPT_PLANT_COIL_IN_LL_OUTPUT)

that adds up via the C2DOF matrix to give the POS DoF and I noticed that these interior nodes can take on large values but always sum up to zero because the pair (UL, LL) was always the negative of (UR,LR). These things should have the same sign, at least in our case where only the POS DoF is excited, so I tracked the issue back to the alternating (-,+,-,+,-) convention for the gains

(X1:SUS-OPT_CTRL_ULCOIL_GAIN, X1:SUS-OPT_CTRL_URCOIL_GAIN, X1:SUS-OPT_CTRL_LRCOIL_GAIN, X1:SUS-OPT_CTRL_LLCOIL_GAIN, X1:SUS-OPT_CTRL_SDCOIL_GAIN)

of the Coil Output filters used in the real system, which we adopted in the hopes that all was well. Anyways, I changed them all back to +1. This also means that we need to change the sign of the gain for the SIDE filter, which I have done also (and check that it damps OK). I decided to reduce the magnitude of the SIDE damping from 1 to 0.1 so that we can see the residuals since the value of -1 quickly sends the error to zero.  I also increased the gain magnitude for the other DoF to 4.

When looking at the plot remember that the values actually represent counts with a scaling of 2^15 (or 32768) from the ADC. I switched back to the original filters on FM1 (e.g. pit_pit ) without damping coefficients present in the FM2 filter (e.g. pit_pit_damp).


FYI, Rana used the ETMY suspension MEDM screen to illustrate the working of the single suspension to me and changed maybe POS and PITCH gains while doing so.


Also, the Medify purifier 'replace filter' indicator issue occurred bcos the moonlight button should have been pressed for 3 seconds to reset the 'replace filter' indicator after filter replacement.

Attachment 1: Screen_Shot_2022-02-03_at_8.23.07_PM.png
Screen_Shot_2022-02-03_at_8.23.07_PM.png
  16644   Thu Feb 3 14:47:12 2022 ChubUpdateElectronicsnew UPS in place

Received the new 1100VA APC UPS today and placed it at the bottom of the valve rack.  I'd connected the battery and plugged the unit into the AC outlet, but did not turn it on due to the power outage this weekend.

  16643   Thu Feb 3 10:25:59 2022 JordanUpdateVACTP1 and Manual Gate Valve Install

Jordan, Chub

Chub and I installed the new manual gate valve (Nor-Cal GVM-6002-CF-K79) and reinstalled TP1. The new gate valave was placed with the sealing side towards the main 40m volume, then TP1 was installed on top and the foreline reattched to TP1.

This valve has a hard stop in the actuator to prevent over torquing.

 

Attachment 1: 20220203_101455.jpg
20220203_101455.jpg
Attachment 2: 20220203_094831.jpg
20220203_094831.jpg
Attachment 3: 20220203_094823.jpg
20220203_094823.jpg
  16641   Wed Feb 2 21:16:23 2022 KojiSummaryBHDOptomechanics configuration for the in-vacuum aux small optics

Asked Jordan to clean 2x 1.5" posts (0.5 dia) and a washer with 1" dia.

 

Attachment 1: PXL_20220203_050156031.jpg
PXL_20220203_050156031.jpg
  16640   Wed Feb 2 18:55:58 2022 KojiSummaryBHDOptomechanics configuration for the in-vacuum aux small optics

Here is more detail of the POP_SM4 mount assembly.

It's a combination of BA2V + PLS-T238 + BA1V + TR-1.5 + LMR1V + Mirror: CM254-750-E03
Between BA1V and PLS-T238, we have to do a washer action to fix the post (8-32) with a 1/4-20 slot. Maybe we can use a 1" post shim from thorlabs/newport.
Otherwise, we should be able to fasten the other joints with silver-plated screws we already have/ordered.

I think TR-1.5 (and a shim) has not been given to Jordan for C&B. I'll take a look at these.

Attachment 1: Screen_Shot_2022-02-02_at_6.46.46_PM.png
Screen_Shot_2022-02-02_at_6.46.46_PM.png
  16639   Wed Feb 2 16:32:02 2022 AnchalSummaryBHDPart IX of BHR upgrade - AS1 free swing test still not good

We still did not get a good AS1 free swinging spectrum. It seems the Side OSEM is reporting coupling to too many DOFs and some extra resonances than we expect. So we did not upload the new input matrix calculated from this test. I'm attaching teh peak fitting (attachment 1) and the diagonalization attempt (attachment 2) to give some idea of what happened. Note how different this fre swinging spectrum looks from the other optics. Given that Yehonathan also felt that somthing might be off with this optic, we need to reevaluate if the suspension has wire not aligned in grove, or it is imbalanced or something else if touching it still.

 

Attachment 1: AS1_FreeSwingData_PeakFitting_20220125.pdf
AS1_FreeSwingData_PeakFitting_20220125.pdf
Attachment 2: AS1_SUS_InpMat_Diagnolization_20220202.pdf
AS1_SUS_InpMat_Diagnolization_20220202.pdf
  16638   Wed Feb 2 16:27:57 2022 AnchalSummaryBHDPart III of BHR upgrade - PR3 inpute matrix diagonalized

The free swinging test was successful. I ran the input matrix diagonalization code (/opt/rtcds/caltech/c1/Git/40m/scripts/SUS/InMAtCalc/sus_diagonalization.py) on the PR3 free-swinging data collected last night. The logfile and results are stored in /opt/rtcds/caltech/c1/Git/40m/scripts/SUS/InMAtCalc/PR3 directory. Attachment 1 shows the power spectral density of the DOF basis data (POS, PIT, YAW, SIDE) before and after the diagonalization. Attachment 2 shows the fitted peaks. I chose to not type out the matrix values now. One can find them in teh repo links above.

 

Attachment 1: PR3_FreeSwingData_PeakFitting_20220125.pdf
PR3_FreeSwingData_PeakFitting_20220125.pdf
Attachment 2: PR3_SUS_InpMat_Diagnolization_20220202.pdf
PR3_SUS_InpMat_Diagnolization_20220202.pdf
  16637   Wed Feb 2 16:22:00 2022 AnchalSummaryBHDPart III of BHR upgrade - PR2 inpute matrix diagonalized

The free swinging test was successful. I ran the input matrix diagonalization code (/opt/rtcds/caltech/c1/Git/40m/scripts/SUS/InMAtCalc/sus_diagonalization.py) on the PR2 free-swinging data collected last night. The logfile and results are stored in /opt/rtcds/caltech/c1/Git/40m/scripts/SUS/InMAtCalc/PR2 directory. Attachment 1 shows the power spectral density of the DOF basis data (POS, PIT, YAW, SIDE) before and after the diagonalization. Attachment 2 shows the fitted peaks. I chose to not type out the matrix values now. One can find them in teh repo links above.

 

Attachment 1: PR2_FreeSwingData_PeakFitting_20220125.pdf
PR2_FreeSwingData_PeakFitting_20220125.pdf
Attachment 2: PR2_SUS_InpMat_Diagnolization_20220202.pdf
PR2_SUS_InpMat_Diagnolization_20220202.pdf
  16636   Tue Feb 1 20:16:09 2022 TegaUpdateBHDPR2 candidate mirror analysis

git repo: git@git.ligo.org:tega-edo/charmirrormap.git

The analysis code takes in a set of raw images, 10 in our case,  for each mirror and calculates the zernike aberration coefficients for each image, then takes their average. This average value is used to reconstruct the mirror height map.  Finally, the residual error between the reconstructed image and the raw data is calculated.

We repeat the analysis for different field of views (FoV) namely 10mm, 20mm, 30mm, 40mm and 46.5mm and save the results in the output folder of the repo.

The analysis output for a 10mm FoV aperture at the mirror center is shown in the attachement. These three images show the input data, the reconstructed mirror surface map and the residual error.

Attachment 1: PR2_M2_data.png
PR2_M2_data.png
Attachment 2: PR2_M2_recon_FoV_10mm.png
PR2_M2_recon_FoV_10mm.png
Attachment 3: PR2_M2_residual_FoV_10mm.png
PR2_M2_residual_FoV_10mm.png
  16635   Tue Feb 1 15:33:28 2022 KojiSummaryBHDOptomechanics configuration for the in-vacuum aux small optics

I've summarized the optomechanics configuration for the in-vacuum aux small optics

It's not obvious here but the post for POP_SM4 is the stack of BA2V, Newport 9953, PLS-T238, LMR1V. The mirror is a CM254-750-E03 curved mirror. This should go on the suspension base. I hope I did not make a mistake there...

Attachment 1: Invac_opto_mechanics_v2.pdf
Invac_opto_mechanics_v2.pdf Invac_opto_mechanics_v2.pdf Invac_opto_mechanics_v2.pdf Invac_opto_mechanics_v2.pdf
  16634   Mon Jan 31 10:39:19 2022 JordanUpdateVACTP1 and Manual Gate Valve Removal

Jordan, Chub

Today, Chub and I removed TP1 and the failed manual gate valve off of the pumping spool.

First, P2 needed to be vented in order to remove TP1. TP1 has a purge valve on the side of the pump which we slowly opened bringing the P2 volume up to atmosphere. Although, this was not vented using the dry air/N2, using this purge valve eliminated the need to vent the RGA volume.

Then we disconnected TP1 foreline, removed TP1+8" flange reducer, then the gate valve. All of the removed hardware looked good, so no need to replace bolts/nuts, only needs new gaskets. TP1 and the failed valve are sitting on a cart wrapped in foil next to the pumping station.

Attachment 1: 20220131_100637.jpg
20220131_100637.jpg
Attachment 2: 20220131_102807.jpg
20220131_102807.jpg
Attachment 3: 20220131_102818.jpg
20220131_102818.jpg
Attachment 4: 20220131_100647.jpg
20220131_100647.jpg
  16632   Fri Jan 28 16:35:18 2022 AnchalSummaryBHDAS1, PR2 and PR3 set to trigger free swing test

AS1, PR2 and PR3 are set to o go through a free swinging test at 3 am. We have used this script (Git/40m/scripts/SUS/InMatCalc/freeSwing.py) reliably in the past so we expect no issues, it has a error catching block to restore all changes at the end of the test or if something goes wrong.

To access the test, on allegra, type:

tmux a -t AS1
tmux a -t PR2
tmux a -t PR3

Then you can kill the script if required by Ctrl-C, it will restore all changes while exiting.

 

  16631   Fri Jan 28 11:30:52 2022 KojiSummaryBHDPart III of BHR upgrade - PR2 OSEM finalized, reinsall LO1 OSEMs

All green! Great work, Team!

  16630   Fri Jan 28 10:37:59 2022 PacoSummaryBHDPart III of BHR upgrade - PR2 OSEM finalized, reinsall LO1 OSEMs

[Paco]

Thanks to Koji's hotfix on the PR2 SatAmp box last evening, this morning I was able to finish the OSEM installation for PR2. PR2 is now fully damped. Then, I realized that with the extreme rebalancing done in ITMX chamber, LO1 needed to be reinstalled, so I proceeded to do that. I verified all the degrees of freedom remained damped.

I think all SOS are nominally damped, so we are 90% done with suspension installation!


SUSPENSION STATUS UPDATED HERE

  16629   Thu Jan 27 20:46:38 2022 KojiSummaryBHDPart III of BHR upgrade - Install PR2, balance, and attempt OSEM tuning
  • Started debugging D1002818 / S2100737 (8:30PM)
  • Confirmed the issue of the negative output of the UR sensor with the dummy OSEM connected at the air side of the ITMY chamber. Both PD Out and PD Mon have negative outputs.
  • The same issue remains when the dummy OSEM box is connected to the chassis with a short DB25M/F cable at the rack.
  • Started debugging the setup at the workbench.
    • CH1 TIA Output=-3.0V / CH2 (in question) TIA Output =-2.7V => No Problem
    • CH1 Whitening Out=+3.0V / CH2 Whitening Out=-1.4V => Problem
    • Resolder the components around whitening CH2 => no change
    • Remove AD822 and replace with a new one => CH2 Whitening OUt = +2.7V ==> Problem solved
    • PD1~3 channels of the left and right PCBs tested with the OSEM box ==> nearly +3V/-3V differential output (All Clear)
    • Chassis closing
  • Chassis restored in Rack 1Y1 and the normal output with the dummy OSEM box confirmed
  • Mission Completed (9:30PM)
  • Elog finished (9:40PM)
  • Case closed
Attachment 1: Screen_Shot_2022-01-27_at_20.33.56.png
Screen_Shot_2022-01-27_at_20.33.56.png
Attachment 2: Screen_Shot_2022-01-27_at_21.30.16.png
Screen_Shot_2022-01-27_at_21.30.16.png
  16628   Thu Jan 27 18:03:36 2022 PacoSummaryBHDPart III of BHR upgrade - Install PR2, balance, and attempt OSEM tuning

[Paco, Anchal, Tega]

After installing the short OSEMs into PR2, we moved it into ITMX Chamber. While Tega loaded some of the damping filters and other settings, we took time to balance the heavily tilted ITMX chamber. After running out of counterweigths, Anchal had to go into the cleanroom and bring the SOS stands, two of which had to be stacked near the edge of the breadoard. Finally, we connected the OSEMs following the canonical order

LL -> UR-> UL

LR -> SD

But found that UR was reading -14000 counts. So, we did a quick swap of the UR and UL sensors and verified that the OSEM itself is working, just in a different channel... So it's time to debug the electronics (probably PR2 Sat Amp?)...


PR2 Sat Amp preliminary investigation:

  • The UR channel (CH1 or CH4, on PR2 Sat Amp)  gives negative value as soon as an OSEM is connected.
  • Without anything connected, the channel reports the usual 0V output.
  • With the PDA inputs of PR2 Sat Amp shorted, we again see 0V output.
  • So it seems like when non-zero photodiode current goes, the circuit sees a reversal of gain polarity and the gain is roughly half in magnitude as the correct one.
ELOG V3.1.3-