ligo-ex ligo-ds
  Richardson Lab Experimental Log, Page 3 of 10  Not logged in ELOG logo
Entry  Wed Jan 10 15:27:18 2024, Shane, Update, Cleanroom, cleanroom cleaning and particle count 
[Aiden, Shane]

cleaning cleanroom and particle count

  • 2:03 pm: changed sticky floor mats
  • 2:05 pm: started particle count
    • zone 3:
      • 0.3 u: 4863
      • 0.5 u: 1205
      • 1.0 u: 872
    • zone 4:
      • 0.3 u: 1953
      • 0.5 u: 789
      • 1.0 u: 457
  • 2:35 pm: began surface check and wipedown, including softwalls and ceiling tiles
  • 2:45 pm: started vacuuming the floor
  • 2:56 pm: finished vacuuming the floor
  • 2:57 pm: started mopping the floor
  • 3:01 pm: finished mopping the floor
  • 3:02 pm: started cleaning the buckets
  • 3:05 pm: started mopping with IPA wipes
  • 3:08 pm: finished mopping with IPA wipes
  • 3:09 pm: started particle count
    • zone 3:
      • 0.3 u: 5528
      • 0.5 u: 2203
      • 1.0 u: 1662
    • zone 4:
      • 0.3 u: 1080
      • 0.5 u: 415
      • 1.0 u: 332
Entry  Wed Jan 31 14:37:26 2024, Shane, Summary, CDS, path directions for CyMAC model and parts library 
Path to cds parts library in Matlab simulink: /usr/share/advligorts/src/src/epics/simLink. File name CDS_PARTS.mdl Path to user models: /opt/rtcds/usercode/models, using file name c1msc.mdl
Entry  Mon Feb 19 14:40:21 2024, Shane, Update, CDS, MEDM screen for FROSTI temp readouts IMG_6094.jpegIMG_6092.jpeg
Here's the latest draft of the MEDM screen for the FROSTI heating elements' temperature readouts. Note that the MEDM screen isn't actually this grainy, this just happens to be a photo of the lab monitor's screen off a phone.
Entry  Wed Feb 21 11:58:30 2024, Shane, Update, Cleanroom, cleanroom cleaning and particle count 
[Luke, Shane, Tyler]

cleaning cleanroom and particle count

  • 11:50 am: ran zero count test on particle counter
  • 11:55 am: started particle count
    • zone 3:
      • 0.3 u: 1787
      • 0.5 u: 581
      • 1.0 u: 166
    • zone 4:
      • 0.3 u: 623
      • 0.5 u: 290
      • 1.0 u: 124
  • 12:17 pm: began surface check and wipedown, including softwalls
  • 12:25 pm: started vacuuming the floor
  • 12:36 pm: finished vacuuming the floor
  • 12:44 pm: started mopping the floor
  • 12:57 pm: finished mopping the floor
  • 12:58 pm: started cleaning the buckets
  • 12:59 pm: started mopping with IPA wipes
  • 1:05 pm: finished mopping with IPA wipes
  • 1:06 pm: changed sticky floor mats
  • 1:08 pm: started particle count
    • zone 3:
      • 0.3 u: 1621
      • 0.5 u: 581
      • 1.0 u: 332
    • zone 4:
      • 0.3 u: 1080
      • 0.5 u: 457
      • 1.0 u: 249
Entry  Fri Feb 23 15:01:48 2024, Shane, Update, CDS, Latest draft of MEDM screen for FROSTI readouts IMG_6128.jpg23.jpg
Here's the latest draft of the MEDM screen for the FrOSTI temp and power readouts. Also, debugged the text readout boxes so they're now correctly reading out the live temperature and power values.
Entry  Thu Feb 29 17:16:48 2024, Shane, Update, CDS, MEDM screen for FROSTI T/P readouts IMG_6259.jpeg
Here's the latest draft of the MEDM screen for the FROSTI temp and power readouts, now with a button linking to the c1msc file display. Size/color/label are all changeable, if adjustment is needed. Checked in execute mode as well, and it's working correctly. Also noticed that the MEDM file name has been changed to FROSTI.adl, which I'm noting here for future reference. Still in medm_sandbox directory.
Entry  Wed Apr 17 15:07:04 2024, Shane, Update, Cleanroom, Cleanroom cleaning and particle count 
[Mohak, Luke, Luis, Shane, Cynthia, Michael, Xuesi]

cleaning cleanroom and particle count

    NOTE: particle counter was found dead, with the charging dock unplugged. For future reference, if you need to unplug the dock, please either plug it back in when you're done, or make a note in an elog so someone else can come down and charge it.

  • 1:07 pm: ran zero count test on particle counter
  • 1:26 pm: started particle count
    • zone 3:
      • 0.3 u:1787
      • 0.5 u:457
      • 1.0 u:41
    • zone 4: We were only able to charge the particle counter a small amount before starting the cleaning, so it died again halfway through this measurement, and we didn't get results for zone 4. In interest of time, we just put it on the charger and started the cleaning.
    • 1:49 pm: began surface check and wipedown, including softwalls
    • 2:16 pm: started vacuuming the floor
    • 2:24 pm: finished vacuuming the floor
    • 2:26 pm: started mopping the floor
    • 2:32 pm: finished mopping the floor
    • 2:32 pm: started cleaning the buckets
    • 2:35 pm: started mopping with IPA wipes
    • 2:43 pm: finished mopping with IPA wipes
    • 2:43 pm: changed sticky floor mats
    • 2:45 pm: started particle count
      • zone 3:
        • 0.3 u: 1288
        • 0.5 u: 124
        • 1.0 u: 0
      • zone 4:
        • 0.3 u: 415
        • 0.5 u: 290
        • 1.0 u: 0
Entry  Thu May 16 15:23:14 2024, Shane, Update, Cleanroom, Cleanroom cleaning and particle count 
[Luis, Michael, Luke, Shane]

cleaning cleanroom and particle count

  • 1:45 pm: ran zero count test on particle counter
  • 1:50 pm: started particle count
    • zone 3:
      • 0.3 u: 2660
      • 0.5 u: 332
      • 1.0 u: 41
    • zone 4:
      • 0.3 u: 8106
      • 0.5 u: 2494
      • 1.0 u: 831
  • 2:08 pm: began surface check and wipedown, including softwalls
  • 2:22 pm: started vacuuming the floor
  • 2:39 pm: finished vacuuming the floor
  • 2:43 pm: started mopping the floor
  • 2:53 pm: finished mopping the floor
  • 2:54 pm: started cleaning the buckets
  • 2:59 pm: started mopping with IPA wipes
  • 3:06 pm: finished mopping with IPA wipes
  • 3:10 pm: changed sticky floor mats
  • 3:06 pm: started particle count
    • zone 3:
      • 0.3 u: 1496
      • 0.5 u: 83
      • 1.0 u: 0
    • zone 4:
      • 0.3 u: 789
      • 0.5 u: 83
      • 1.0 u: 41
Entry  Tue Jun 25 12:34:18 2024, Shane, Update, Cleanroom, cleanroom cleaning and particle count 
[Luke, Shane, Xuejun, Mohak, Michael, Tyler, Cynthia]

cleaning cleanroom and particle count

  • 10:45 am: ran zero count test on particle counter
  • 11:02 am: started particle count
    • zone 3:
      • 0.3 u: 3284
      • 0.5 u: 1247
      • 1.0 u:332
    • zone 4:
      • 0.3 u: 1829
      • 0.5 u: 581
      • 1.0 u: 207
  • 11:15 am: began hepavac of rest of lab
  • 11:19 am: began surface check and wipedown, including softwalls
  • 11:32 am: finished hepavac of rest of lab
  • 11:35 am: started vacuuming the cleanroom floor
  • 11:45 am: finished vacuuming the floor
  • 11:47 am: started mopping the floor
  • 11:55 am: finished mopping the floor
  • 11:56 am: started cleaning the buckets
  • 11:57 am: started mopping with IPA wipes
  • 12:02 pm: finished mopping with IPA wipes
  • 12:03 pm: changed sticky floor mats
  • 12:04 pm: started particle count
    • zone 3:
      • 0.3 u: 3117
      • 0.5 u: 374
      • 1.0 u: 124
    • zone 4:
      • 0.3 u: 4531
      • 0.5 u: 540
      • 1.0 u: 0
Entry  Thu Jun 27 13:42:02 2024, Shane, Update, Cleanroom, cleanroom 5 zone particle count measurement 24.png
Here's today's 5 zone measurement of the cleanroom. We're above the limit by a bit in zone three (all three size ranges), likely as a result of the recent work installing FROSTI, so it could probably use another focused cleaning. Everything else is below the limit.
Entry  Mon Jul 8 17:01:45 2024, Shane, Update, CDS, New CyMAC internal layout updated_cymac.jpeg
[Jon, Shane] Internal layout of CyMAC has been updated (labeled image attached) to accommodate the replacement of the two ribbon cables. Looking down on the chassis from the front, and going from left to right, the new placement is as follows: BIO card, DAC adapter board, ADC adapter board, DAC card, ADC card. NOTE: As part of ADC-DAC loopback testing, we're disconnecting from the FROSTI readout chassis and using the cables to connect directly from ADC input channels to DAC output channels . Initial testing confirmed functionalility of all 32 ADC input channels and the first 8 DAC output channels.
Entry  Tue Jul 9 18:19:50 2024, Shane, Update, CDS, ADC-DAC loopback testing and IOLAN installation iolanServerTerminal.jpegADC-DAC_Loopback_Testing.xlsxupdatedc1msc.jpeg
[Shane, Jon]

Finished ADC-DAC loopback testing today (see attached xlsx file or access directly here). All looks well with the first 8 channels, with the gain hovering just under 2. Also edited c1msc model in simulink to add channels 7-15 (the last 8 channels), and changed the rate back to 64K. See image 1 for the updated c1msc model. The last 8 channels are also looking good and show no problems, with slightly more scattering for the gain, but all values very close to 2.

We also installed the new eight-channel Perle IOLAN SDS8 terminal server today. Image attached.

NOTE: When we were installing it, we noticed an energized wire dangling from the 24V power supply. Has since been fixed and put back into place.

    Reply  Tue Jul 16 18:43:07 2024, Shane, Update, CDS, ADC-DAC loopback testing and IOLAN installation Follow-up_ADC-DAC_Loopback_Testing.xlsx
UPDATE: Follow up ADC-DAC loopback testing now complete, matching all the ADC channels to a single DAC channel, and then matching all the DAC channels to a single ADC channel (see attached xlsx file or access directly here). Also note c1msc model file has been updated to include the second set of 16 ADC channels. The newly added channels also have their own filter modules, but those are not needed for anything other than the loop-back testing and can now be deleted if we don't want to keep them.

Quote:
[Shane, Jon]

Finished ADC-DAC loopback testing today (see attached xlsx file or access directly here). All looks well with the first 8 channels, with the gain hovering just under 2. Also edited c1msc model in simulink to add channels 7-15 (the last 8 channels), and changed the rate back to 64K. See image 1 for the updated c1msc model. The last 8 channels are also looking good and show no problems, with slightly more scattering for the gain, but all values very close to 2.

We also installed the new eight-channel Perle IOLAN SDS8 terminal server today. Image attached.

NOTE: When we were installing it, we noticed an energized wire dangling from the 24V power supply. Has since been fixed and put back into place.

 

Entry  Fri Aug 2 13:50:22 2024, Shane, Update, CDS, Serial Comm. Test (Agilent Turbo Pump) pinouts.jpeg
Did a brief communication test with the agilent turbo pump today, to see if we could get serial communications up and running for it. Used a simplified python script with sockets package to establish a connection and send a simple command to query the pump's operational status. The connection was successful, and had no issues establishing. The command also sent successfully, and received a response. The response didn't make sense, though, as all the possible statuses correspond to integers 0-7, and this test returned the integer 15. Need to troubleshoot some more to figure out why it's returning nonsense values. Possible match-up issue with the way the information is being encoded on each end? At the very least, connection and command sending are both working fine, and this showed that the pin-out connections we were assuming (image attached) are correct for basic connection to work.
Entry  Tue Oct 1 19:41:23 2024, Shane, Update, CDS, CyMAC Timing Chassis Issue IMG_5917.jpegIMG_5803.jpegIMG_5804.jpeg
[Shane, Luis] Summary of the issue we've been having with the timing chassis: when we connect only the Valon 5015 to power, the timing signal comes out of it sinusoidal as expected and the status lights are steady and all looks good. As soon as we connect the 3010 to power, the signal (both coming out of the 5015 and coming out of the 3010) go flat and the status lights of the 5015 start to flicker. We think what may be going on is that the 5015 is drawing just enough power to survive on its own, but when the current gets split to go to the 3010 as well, the 5015 takes more than it needs and becomes overpowered, and thus no longer outputs anything. We want to test further by powering them with two separate power supplies, but we need another one of the power connectors for the 3010 (the only one we have branches out from the connector to the 5015 and we don't want to cut any of the wires). Images of the inside of the chassis, along with two roughly sketched circuit diagrams (one showing the current setup, in which they're powered by the same source, and one showing a possible test set up, in which they're powered separately.
Entry  Thu Oct 3 19:35:04 2024, Shane, Update, Cleanroom, Cleanroom cleaning and particle count 
[Luke, Michael, Cynthia, Mary]

cleaning cleanroom and particle count

  • 12:25 pm: started particle count
    • zone 3:
      • 0.3 u: 4614
      • 0.5 u: 872
      • 1.0 u:83
    • zone 4:
      • 0.3 u: 2411
      • 0.5 u: 415
      • 1.0 u: 83
  • 12:48 pm: began surface check and wipedown, including softwalls
  • 1:20 pm: started vacuuming the floor
  • 1:30 pm: finished vacuuming the floor
  • 1:34 pm: started mopping the floor
  • 1:40 pm: finished mopping the floor
  • 1:40 pm: started cleaning the buckets
  • 1:42 pm: started mopping with IPA wipes
  • 1:50 pm: finished mopping with IPA wipes
  • 1:51 pm: changed sticky floor mats
  • 3:44 pm: started particle count
    • zone 3:
      • 0.3 u: 3207
      • 0.5 u: 624
      • 1.0 u: 83
    • zone 4:
      • 0.3 u: 916
      • 0.5 u: 83
      • 1.0 u: 0
Entry  Thu Oct 17 13:24:23 2024, Shane, Update, CDS, Timing Chassis issue identified IMG_6462.jpegIMG_6464.jpeg

[Ma, Luis, Shane]

Working theory for the timing chassis issues had been that the 1A breaker was tripping and causing the failure of the Valon 5015 and 3010 to output the timing signal correctly. We just tried bypassing the breaker, running 6 V on the benchtop power supply (set the current limit to 1.5A), with the 5010 generating the sine wave to pass to the 3010. All worked correctly, and there were no issues. Square wave outputted by the 3010 was exactly as desired (image attached) at the correct frequency, and this confirms the issue was the breaker, not the valon 5015. Ready to go ahead with ordering a new replacement breaker.

Entry  Fri Oct 25 10:56:30 2024, Shane, Update, CDS, Timing Chassis fixed and reinstalled successful_timing.jpeg
[Ma, Shane]

We replaced the 1A breaker in the timing chassis today with a 4A one, and tested that all is working well. The chassis successfully outputted the correct signal (image attached). The real time models have also been restarted and the CyMAC diagnostics screen is showing all green flags. Timing chassis has been closed up and reinstalled in the server rack.

Entry  Thu Nov 14 11:58:05 2024, Shane, Update, CDS, Turbo pump connection troubleshooting 
Attempted connection to the TV551 turbo pump through Varian/Agilent's software on spica. Successful connection established, and we are able to read out al the readings associated with the pump (status, temperature, etc) through the software, which is actually pretty extensive and well organized. Was able to stop and restart the pump with no issues. Serial communications seem to be working fine, and the current serial settings (baud rate 9600, serial type RS232) all match what the Iolan was expecting with the previous connection test. Also notable: the code used for the previous (failed) connection test is written using 'Letter protocol', which is the older of the two communications protocols supported by these kinds of pumps. This rules out the pump being too old to accept the newer communication format as the issue, since it's the older format being used anyway. Will continue trouble shooting to determine why previous connection test failed.
Entry  Sun Apr 10 15:39:49 2022, Rutuja Gurav, HowTo, Computer Scripts/Programs, HowTo: Renew the Let's Encrypt SSL certificate using certbot 

Port 80 is kept closed by default. This might be causing the certbot auto-renewal cronjob to fail. Therefore we must renew the certificate manually.


Step 1: Open port 80. (This is needed as the certificate renewal process runs some tests which requires client communication over port 80)


Step 2: Run the following command


sudo certbot certonly --force-renew -d richardsonlab.ucr.edu


Step 3: Confirm the certificate was renewed by running the following command


sudo certbot certificates

Entry  Tue Feb 13 13:02:41 2024, Pooyan, Update, Interferometer Simulations, Cacity sacn of Fabry-Perot  IFOSim_update_2_13_24.pdf
Created a simple model of Fabry-Perot cavity in SIS, and did a cavity scan. Total power in the cavity, 00 mode, and HOMs is measured.
Entry  Wed Mar 27 00:03:57 2024, Pooyan, Update, Computers, Chimay relocation to Physics 1129 Chima_front.jpgChimay_back.jpg

[Jon, Pooyan]

Moved Chimay from the server rack in Physics 1119 to a new rack in Physics 1129. It is connected to the switch in that rack and has the same ip address as before.

All services are up and running.

It appears that JupyterHub creates some processes whenever a user connects to an instance of it, but in some cases does not stop those processes after the user is not using that instance. This results in having lots of running idle processes, each using a small bit of the resources. Those processes are killed now as a result of rebooting. It might be a good idea to manually restart JupyterHub (or the whole machine) every few months to avoid this.

Entry  Mon Apr 8 14:43:29 2024, Pooyan, Update, Interferometer Simulations, SIS update single and coupled cavities IFOSim_SIS__update_4_8_24.pdfScreen_Recording_2024-03-31_at_2.46.29_AM.mov
[Pooyan, Cynthia]

Attached is a brief recap PDF file. A video file showing separate HOMs plots for the cavity scan with ETM08 surface map is also attached.

The codes are available at https://git.ligo.org/uc_riverside/hom-rh/-/tree/main/SIS

Entry  Mon Jun 24 21:38:25 2024, Pooyan, Infrastructure, Computers, Computer server changes in 1119 and 1129 IMG_6889.jpgIMG_6890.jpg

[Jon, Pooyan, Tyler]

 

A few computer machine changes have been made. 

 

  • Logrus moved from 1119 to 1129. It is up and running with the same IP address as before. 
  • A new Windows machine (host name: spica, IP:192.168.1.14) is installed in the 1119 server rack. It is connected to the RGA scanner with the serial port and is specifically used for that purpose. 
    • Update: The machine was off on 6/25, although it was left on 6/24. We think that it might have been because of Windows' default setting to suspend/hibernate the machine after idleness. To resolve this, I used  "powercfg /change" command to set all the following parameters equal to zero. The machine is still running on 6/26. 

    monitor-timeout-ac
    monitor-timeout-dc
    disk-timeout-ac
    disk-timeout-dc
    standby-timeout-ac
    standby-timeout-dc
    hibernate-timeout-ac
    hibernate-timeout-dc
  • A new Debian machine (hostname: megatron, IP:192.168.1.16) is installed in the 1129 server rack. This machine is intended to be used for FEA/simulation work. A new 2TB WD Green SSD is used as its main disk drive. 

     At the moment, “controls” is the only user, and there are no apps/libraries installed on the machine.

    • Update: Jon installed LIGO cds-workstation tools and MiniConda on 6/26. 
    • Update: Pooyan and Liu set the following conda environments:
      • Env named “finesse” with Python 3.12.3 and Finesse version 3.0a24 installed. Finesse was installed via the source code. The subdirectory “/home/controls/packages” is used to store the package sourcecodes.
      • Env named “fenicsx” with the same version of Python and Finesse as the previous env, with the latest version of FEniCSx (0.8) and the test-mass-thermal-state installed.  
Entry  Mon Jul 15 14:28:32 2024, Pooyan, Update, Interferometer Simulations, aLIGO test mass surface profiles  

Created a Google Slides presentation to summarize all the mirror surface map information that we use for simulating interferometers. 

A+ expected maps are based on correspondence with G. Billingsley. The estimate for the A+ ITMs will be to take the “as polished” data and add coating non-uniformity to it. (T2000398) Neither of these are scaled for the precise thickness of the Ti:Ge coatings.

Google Slides link: https://docs.google.com/presentation/d/1ge-ciAiEdNyyTvSShYdZz2JpACFRY2W3JDpxHRqMnOQ/edit?usp=sharing

 

 

 

Entry  Mon Jul 15 14:49:06 2024, Pooyan, Update, Computers, Synology NAS server setup 

Installed a Synology NAS server (Synology RackStation RS1221) in lab room 1129, with host name “scribe” and ip “192.168.1.17”. It is mounted on the rack and each of its 8 storage bays has a 2TB SSD disk. It will be used to set up automated backups of all the lab machines (e.g., chimay, logrus, megatron).

One shared storage is set on it with SHR-2 as its RAID type. It can tolerate the failure of two disks and has 10.4TB of total capacity. 

We can use both rsync and dd to create backups of the system. A suggested backup schedule could be daily rsync backups and bi-weekly disk snapshots using dd. 

 

Entry  Mon Sep 9 14:27:36 2024, Pooyan, Infrastructure, Computers, Chimay backup attempt 

One ongoing work is to make all lab machines automatically backed-up on Scribe on a daily basis. The updates should be boatable and stored for some time (potentially a few weeks) on Scribe. Making whole disk images has already been tried for some of the machines with no problems. (e.g., Cymac and WorkStations)

The same thing can not be done with Chimay though, as it currently has one huge RAID-controlled volume that stores all the information (OS, home directories, and NDS-downloaded data). Creating daily full disk images of such a system is not practical. 

Here is the plan we came up with to overcome this issue:

  1. Create one full disk image of Chimay and store it on Scribe (it was already done)
  2. Move the nds-downloaded raw data temporarily to Scribe and remove it from Chimay
  3. Make another full disk image of Chimay
  4. Burn this image to a single disk and boot chimay with it
  5. Restore the rest of Chimay disks and move the NDS data back

     

On the weekend (Sat and Sun 9/7-8) I tried to execute these steps. There wasn't enough free space left on Scribe to move all the NDS data to it, so I stored part of this data temporarily on WS4. Then I also checked storage-consuming directories and, in one case, removed some non-important stored files. As there was no free space left on Scribe to execute step no. 3, I initiated storing the image on WS3. Unfortunately, a couple of different trials of the image-creation process failed as there was not enough free space on WS3 to accommodate Chiamy image as well. I was not able to reduce the image size such that it can be stored on WS3. 

 

These are the options left for us to get this work done. 

  1. Distribute the NDS files between different machines to make enough free space on Scribe for the image and then follow the previous plan
  2. Shrink the Chimay drive size, create the image and then follow the previous plan
  3. Temporarily transfer some services to Megatrone (Network gateway, Wiki, elog) and recreate chimay and its services from scratch
Entry  Wed Aug 17 16:04:30 2022, Phoebe Zyla, Summary, Lore, Testing the Cartridge Heater and Collecting FLIR Data Screenshot_(74).pngScreenshot_(75).pngScreenshot_from_2022-08-15_11-24-40.pngAcquisitionImage(Aug-15-2022_14_16).jpg

We have tested the heater to find emissivity, mounted the heater system to the optical table, and have taken irradiance maps of the heater projected onto the screen.

The heater's emissivity was determined by using a thermocouple in conjunction with the FLIR's temperature calibration. To attach the thermocouple to the heater initially, I used Kapton tape and ran both the wires of the heater and the thermocouple through the heater bridge. This allowed for the heater to rest on an optical post and be observed without anyone directly holding it, but there were some measurement issues. The thermocouple had a very wide range of temperatures it was reading, which may have been due to intermittent contact or a short between the two legs of the thermocouple. To solve this and make the temperature measurements more stable, we pried apart the two ends of the thermocouple (to ensure there was no short) and put tape on either side, leaving the end connection bare. This was then taped to the heater, and the thermocouple was much more stable. We also used a K-type thermocouple that has an adhesive tape on it already, which assisted with the intermittent contact as well. With the thermocouple measuring the temperature of the heater, we could point the FLIR directly at the heater and calibrate the emissivity until the FLIR and the thermocouple agreed. Cassidy's emissivity calculator was also used, as I could input a temperature and observe what the emissivity of an area was based on that temperature. We found the emissivity of the heater to be 0.57.

As a note, when observing the heater with the FLIR, it appeared that there was a hot spot in the center, where the Kapton tape sat. Because the Kapton has a different emissivity than the 304 stainless steel of the heater, the FLIR will read it as having a different temperature than it actually does. When using the FLIR in the future, be sure to ascertain whether there is a temperature difference somewhere or if there may be different emissivities.

Additionally, the first heater that I used was taken to a very high temperature and oxidized. The emissivity of this oxidized heater is not known, but could be good information for knowing how oxidation affects these heaters specifically.

To mount the heater system in front of the screen, I used 1/2'' optical posts and the mount I designed using COMSOL's CAD program. The heater was originally 2.5 inches away from the screen, and has since been moved back by an additional two inches so that we could observe the heater side of the screen with the FLIR. We wanted to see what temperature the heater side of the screen was when irradiated by the heater, and how that compared to the camera side of the screen. When the heater ran at 1.12 W of input power, the heater side of the screen had a max temperature of around 29.7 C, and the camera side of the screen read at about 29.5 C. This means that there is very little thermal loss between the two sides of the screen, and any insulation that the screen's adhesive may have is largely negligible. Additionally, the camera was placed at an angle and undetermined distance for these tests, confirming that the temperature measurements compensate well/don’t depend on changes in angle or distance between the camera and the screen. However, there was spots on the back of the screen that the camera was measuring as hot spots where there shouldn’t have been any. I have included an example below. It would be useful to run a test where the camera is directly on the back of the screen without the heater to characterize the screen and see if the hot spots are physically present on the screen or if this is an artifice of the camera because of something like angle of viewing.

Taking irradiance maps of the screen was straightforward. After checking that the emissivity of the screen is 0.99 by viewing it at room temperature, we monitored the max temperature while slowing increasing the wattage the heater was running at. There is not a large change until the heater is at around 95 C, at which point the screen began to rise in temperature from 27 C to 28 C. We took measurements of this while the heater was 2.5 and 4.5 inches away from the screen. The irradiance map has a very symmetrical and circular shape, but does not have the ring pattern that we expected. There may be a few reasons for this: there could be some conduction between the two sides of the screen that is causing the pattern to spread further, the heater setup may not be as ideal as it was modeled to be, or there could be a different, unknown issue.

TO DO:

- It would be useful to run a test of the camera in multiple different positions to ensure our conclusion that the camera’s measurements don’t depend on angle or distance (or that these factors are well accounted for in the current temperature calculations) is correct.

- Measure the back of the screen straight on to identify bright spots and possible reasons as to their appearance.

- Recalibrate camera to ensure it is still correct after testing in multiple positions.

- Take another irradiance map of the screen at a higher input power, as well as moving the heater close/further away to try and replicate the COMSOL irradiance maps. It would be useful to also redo the COMSOL modeling at lower powers and variable distances.

Pictures included of full table setup, the heater mount, the heater with Kapton tape attaching the thermocouple as well as FLIR's measured irradiance map.

Entry  Fri Jul 22 13:20:28 2022, Phoebe, Update, , Comsol 
I will be using comsol until 1:30 pm today. I will be updating the model for the heater mount to be thicker in certain areas, so that it can feasibly be 3D printed. Specifically, the radius of the center cartridge mount has been increased to add thickness to the pipe and the arms of the bridge. This will allow us to print with a much smaller chance for error, as the printer can print objects with a minimum length of 1 mm.
Entry  Mon Jan 23 17:26:15 2023, Peter Carney, Update, General, Oven cleaning 
Aiden and Cao Turned on the oven to 120 deg C for 12 hours. After 12 hours, put it at 200 deg C for 48 hours.
Entry  Sat Feb 4 17:01:03 2023, Peter, Update, VLC Electronics, Laser Data OmegaX_M2_Fit_3.pngOmegaY_M2_Fit_3.png
Peter and Ryan took laser beam data. Configuration: 100mm focal length lens is ~100mm from lens. 150mm focal length lens is ~200mm from first lens. Beam waist is ~420mm from second lens. Beam waist is very small still. Had to input large amounts of error in data collection. Took width data successively at points near waist and at >= Rayleigh range. Plots are shown below. Key points: Took a while to figure out optimum configuration for lenses to be placed so that an accessible beam waist could be obtained. Beam waist is still very small. May need to do an ABCD calculation to see if there is anything bigger that can be obtained.
Entry  Tue Feb 28 19:31:05 2023, Peter, Update, VLC Electronics, 532 M2 Measurements X_width_and_Y_width.png
Took M2 measurements today. Configuration: Lens 1 (f = 50mm) at 0mm. Lens 2 (f = 150mm) at 200mm, camera at 350mm. The laser beam was being moved in -z direction on track (so further away from the first lens). Quick data shown in the sheets plot. Not a real fit. I was trying to see where the beam waist was if there even was one. Seems that it is much further than we have room for on the track. Will need to come back and take more data. I suggest maybe Dr. Richardson or Cao come and see the configuration in person and how the beam diverges for themselves on the detector card. Maybe they can offer pointers to make this go smoother.
Entry  Tue Feb 28 19:33:51 2023, Peter, Update, , 532 M2 Measurements 
Y axis of plot in units of micrometers. X axis in units of millimeters.
Entry  Thu Mar 9 12:03:59 2023, Peter, Update, VLC Electronics, 532 M2 Measurements OmegaY_M2_Fit_3.pngOmegaX_M2_Fit_3.pngoptical_setup.jpg
Took more M2 Data today. Picture of the optical set up is shown below. lens1 f = 100mm, lens2 f = 50mm, lens3 f = 150mm. There was a nice converging/diverging beam profile, and the beam waist was able to be read by the camera. I took as much data as I could before clipping loss. The M2 value is quite high.
Entry  Fri Mar 10 12:08:09 2023, Peter, Update, VLC Electronics, 532 M2 Measurements OmegaX_M2_Fit_4.pngOmegaY_M2_Fit_4.png
Took more M2 laser data today. The configuration is the same as before except now the beam camera is the only component moving. Pictures can be seen below. The beam shape in x and y is very consistent with low error. However, the M2 value is still a bit high.
Entry  Tue Apr 4 09:39:58 2023, Peter, Update, VLC Electronics, 532 M2 Measurements OmegaY_M2_Fit_8.pdfOmegaX_M2_Fit_8.pdfM2_Measurements_Set_Up.svgBeam_Data_8_3lens.txt
Final M squared measurements were taken Wednesday, 3/29/23 by Peter and Ryan Hinosawa. 5 separate sets of data were taken, and upon discussion, we declared the plots shown below in attachment 1 and 2 as the final plots of our M squared measurements. The optical design of the M squared measurement process is given in attachment 3. The laser and three lenses shown below are mounted on the optical table. The track is placed behind the third lens, and the camera is moved along the track to take successive measurements of the beam's width. This will allow us to see a change in the beam's width over its propagation direction. The raw data is given in attachment 4 as a Beam_Data_8_3lens.txt file. This is eventually what gets used to generate the plots shown below. The code to run the analysis on these measurements (as well as analysis on the Gaussian intensity profile fitting) can be found: git@git.ligo.org:uc_riverside/visible-light-cavity.git
Entry  Tue Apr 4 09:53:37 2023, Peter, Update, VLC Update, Laser intensity/polarization drift measurements initial_Intens_measure_set_up.jpg
The set up for the next round of beam characterization measurements has begun. The beam is initially passing through a half waveplate, is split at a polarizing beam splitter, and then stirring mirrors are used to properly aim the beam into photodiodes (not yet installed). This is the current configuration of the set up.
Entry  Thu Apr 6 10:20:43 2023, Peter, Update, VLC Update, Laser intensity/polarization drift measurements Optical_Setup_4-6-23.jpg
More optical components were added to the optical set up for laser intensity / polarization drift measurements. Both lenses and both PDs were added to the configuration, as seen in the image below. The beam is already well aligned into the center of both of PDs, and focused nicely by the lens. Both PD's take BNC connecting cables, and the Red Pitaya takes SMA connecting cables. Since we are currently without a BNC to SMA cable, and we do not want to cut, strip, and crimp what we have, then measurement process cannot proceed until we get the cables.
Entry  Fri Apr 28 11:21:01 2023, Peter, Update, VLC Update, Laser intensity/polarization drift measurements IMG-0183.jpg
The Digi-key cables have arrived, and I have began implementing them in the intensity drift measurements. There was a slight problem initially in connecting the SMA to BNC cables from the photodiode to the red pitaya, since the red pitaya was way on the other side of the lab. Cao and I connected the red pitaya to a new ethernet cable that extended far enough for the red pitaya to sit comfortably on the breadboard with the optics. Right now the PDAs are not connected to the red pitaya. I have connected them to the oscilloscope in order to read out how much voltage they produce upon incidence of 532nm laser light. This was done in order to make sure that they do not surpass the limit of the red pitaya (+-1V). I have not acquired a value for the readout voltage of the PDAs since I had to go to class. I will gather this preliminary data soon.
Entry  Mon May 1 18:56:57 2023, Peter, Update, VLC Electronics, 532nm Intensity Measurement graphs.jpgTime_Series_Trial_1.png
I've configured the two PDA's to the Red Pitaya. I put a 50 ohm resistor connector to each red pitaya input port. This was because the oscilloscope showed that the voltage reading from the P polarization PDA was almost at 1V, which was the limit of the red pitaya. Once both S and P polarization PDA's were connected, I opened the red pitaya's oscilloscope. A screenshot of the voltage readings is shared below. Channel 1 (Yellow) is for S polarization. Channel 2 (Green) is for P polarization. It would seem that there is a significant amount of polarization in the P direction as opposed to the S direction. I then tried running the template time series measurement within the python notebook from channel 1 only. The python notebook graph is shown below. I have not figured out what are the units of time on the x axis, and I have not figured out how to change the amount of time that the red pitaya takes data. A plot of the time series measurement is shown below.
Entry  Tue May 2 15:55:33 2023, Peter, Update, VLC Electronics, 532nm Intensity Measurement IMG-0221.jpgIMG-0222.jpggraphs(1).jpgTime_Series_Trial_2.png
I changed the 1/2 wave plate from the lens mount to the rotational optic mount. This allowed me to rotate the 1/2 wave plate, which changed the respective polarization power transmitting through S and P polarization. Initially, more power was coupled into the P polarization. Now, with the 1/2 plate rotated, both channels are experiencing the same voltage reading. Before feeding the PDA signals into the red pitaya, a 50 ohm terminator had to be placed at the SMA connection port so that the input power into the red pitaya did not exceed 1V. With this configuration, both channels experience about 0.35mV. (See attached) I then opened the Jupyter notebook, and ran a demo time series measurement from the red pitaya. This time, I was able to get a plot featuring both channels (green is P polarization. Blue is S polarization). The plots are consistent with what is shown in the red pitaya oscilloscope. However, the time collection (I'm assuming) only runs for about 0.018s. I will have to write some of my own code to loop over this measurement, and collect more data.
Entry  Thu May 4 14:01:10 2023, Peter, Update, VLC Electronics, 532nm Intensity Measurement graphs(3).jpggraphs(2).jpg
I adjusted the rotational mount of the wave plate to see if the power can be 100% coupled into either S or P polarization. The images shown below of the oscilloscope indicate that this is not possible. The minimum transmitted power we can obtain in either S or P polarization is 75mV. The maximum voltage we obtain in either S or P polarization is ~ 740mV. This means that at a maximum, we can obtain ~ 90% polarization in either direction, indicating that our laser has a slightly elliptical polarization.
Entry  Tue May 16 11:56:33 2023, Peter, Update, VLC Electronics, 532nm Intensity Measurement Time_Series_Trial_3.png
With the configuration the exact same as before, I used the Jupyter notebook in the red pitaya's development package to collect data from both input channels. Last week, I was able to take data, yet only for a very short period of time, and I did not know how to change it. I went online to the red pitaya's user manual to figure out how to change the sampling period for longer. The link to the page is here: https://redpitaya.readthedocs.io/en/latest/appsFeatures/examples/acqRF-samp-and-dec.html#s-rate-and-dec Though I now know how to change the period of time for which data is taken, the maximum amount of time is still only about 8 seconds. So with help from Cao, we looped over the data taking samples, and got a mean value for each iteration. We then put all those mean values in an array, and plotted it. Below, we see a plot of both the S and P polarizations, and a sum of both of them. As seen in the graph, I have set the time to be able to take data for almost 2 minutes. There is some slight drift in the respective intensities. The next steps I believe are to convert the units into watts, and take data for longer periods of time.
Entry  Thu May 18 14:07:08 2023, Peter, Update, VLC Update, 532nm Intensity Measurement Time_Series_Trial_4.pngTime_Series_Trial_5_2hrs.png
I figured out a method in which to capture power measurements including the initial seconds in which the beam is first turned on. I first clear and restart the kernel of the python notebook. Then I run the command to connect the red pitaya oscilloscope package to the input data being taken in both channels. To my understanding, this allows for data acquisition as the code compiles. I then started looping the 1.074s trigger bunches, and then roughly 2 seconds after I ran that command, I went and turned on the laser. The first plot shown is a 2 minute practice trial of me trying this technique to make sure that the python package was correctly registering the input of the red pitaya. It is clear that initially the laser is off, and then as I turned it on, the voltage in each channel spikes, which is compelling evidence that the code is working. I then set the data collection to be 7518 seconds (7000 loops), which is about 2 hours and 5 minutes. I repeated the same technique as for the first plot, only changing the amount of time I collected data. The second plot shown here is the voltage being read in each channel as a function of time. As we can see, over a period of hours, the intensity drifts quite dramatically for the first several minutes, and then begins to stabilize slightly. However, there are still some strong sudden fluctuations in each channel.
Entry  Mon May 22 16:43:28 2023, Peter, Update, VLC Electronics, Laser intensity/polarization drift measurements S-P_Polarization_Diagram.svgPolar_angle_vs_time.pngRel_Intens_vs_time.png
In order to fully analyze the polarization data taken last Thursday, I needed to convert the signal output (which is in volts) to power (units of watts). I used the power meter to accomplish this. Keeping the exact same configuration of PD's and beam splitting, opened the red pitaya's oscilloscope package. I then took the power meter, and held it in front of the PD to measure the amount of Watts at each PD. I then wrote down the corresponding voltage being seen in the red pitaya. I took 5 sets of measurements for each PD to get experimental accuracy. I then used a simple y = mx + b fit to find out the constant m that converts the input wattage into voltage. For the s polarization, the conversion factor is 0.83. For the p polarization, the conversion factor is 1.12. I then used this data to plot polarization angle as a function of time, and the relative intensity drift as a function of time. The plots are shown below. The physical meaning of the polarization angle is shown in the unit circle diagram below, in which P is the total power.
Entry  Wed May 24 14:28:26 2023, Peter, Update, VLC Electronics, Laser intensity/polarization drift measurements Time_Series_Trial_7_16hrs.pngPower_vs_Time_16hrs.pngPolar_angle_vs_time_16hrs.pngRel_Intens_vs_time_16hrs.png
I went in and took polarization drift data for 16 hours. The run started at 6:08pm and finished at 9:15am the next day. The four plots below are the same plots shown for the 2 hour collection and previous trials, except they extend to 16 hours. The only one that is different is the Power vs. Time graph. This is a graph of the actual incoming power of the laser (as opposed to the signal voltage that the PDA's output into the red pitaya). This was done using the calibration factors of the respective PDA's and as we can see, since there is a difference in the calibration factors between detectors, there is a difference in the power that's coupled into S and P polarization.
Entry  Tue Jun 6 16:15:09 2023, Peter, Update, VLC Update, Launch Optics for Visible Light Cavity IMG-0882.jpgIMG-0883.jpg
I assembled the first few components of the launch optics for the visible light cavity. Below is an image of the current table configuration, and the image is how the cavity will be oriented on the table.
Entry  Thu Sep 7 19:24:25 2023, Peter, Update, VLC Update, VLC Launch Chain IMG-3404(1).jpgIMG-3408(1).jpg
The launch optics up to the Faraday Isolator have been added to the breadboard. In the first image, the optics are (from L to R) the stirring mirror, half-wave plate, polarizing cube, 100mm f lens, electro-optical modulator, Faraday isolator, 50mm lens (not part of final design), stirring mirror (not part of final design)
Entry  Mon Oct 9 11:06:17 2023, Peter, Update, VLC Update, VLC Launch Chain IMG-3540.jpgIMG-3538.jpgIMG-3533.jpgIMG-3522.jpg
Implemented the new stage for the EOM. Took power data at different positions in the launch chain. Beam waist: 0.066mm (beam waist is inside EOM). Power before EOM: 0.473mW. Power after EOM: 0.452mW. Power after Faraday Isolator: 0.415mW. Might need to adjust better to configure for clipping losses. Images of setup are attached below.
Entry  Mon Oct 23 07:28:57 2023, Peter, Update, VLC Update, VLC Mode Matching Carney_VLC_Update.pdf
I have attached a pdf with slides of my latest updates.
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