ligo-ex ligo-ds
  Richardson Lab Experimental Log, Page 4 of 11  Not logged in ELOG logo
New entries since:Wed Dec 31 16:00:00 1969
ID Datedown Author Type Category Subject
  389   Fri Jun 28 10:43:13 2024 XuejunUpdateCleanroomFrosti
[Xuejun, Tyler]

We moved Frosti into the cleanroom and debugged it to make sure everything was working. One of the DB25 pins broke off at the connector for element 1 so it needed to be recrimped. Element 6 short circuited but fixed with adjustment to the heater power pin position. We connected the power and sensor connectors to the power box and recalibrated the RTD sensors.

  388   Thu Jun 27 13:42:02 2024 ShaneUpdateCleanroomcleanroom 5 zone particle count measurement
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.
  387   Thu Jun 27 11:09:14 2024 LiuUpdateScripts/ProgramsStraight edge STEP files and ray loss analysis

Drawings and CAD models of the straight-edge designs are exported, and are visualized in SOLIDWORKS. Two are attached. One is a single edge of the evenly spaced polygon design with 16 edges, and the other is the 8x2 design, with two neighboring edges grouped together to replace the original single curved heater.

For the straight edge design in COMSOL, ray power detectors were placed at the heater's front surface. The irradiance is shown in figure. The amount of light rays deposited back to the heater is small when close to the center, where it is closer to the original ring. The ray power increases as we move further away from the center toward the edges. In addition, the total power integrated at the heater's front surfaces is about 21% of the original heater's emitted power. This could account for the power efficiency difference between the straight edge design and the ring design, as shown in plot for instance.

  386   Wed Jun 26 16:39:34 2024 LukeUpdateVACVacuum chamber leak checking
On Tuesday I had isolated the main volume and let it pump down over-night. Today, Wednesday, I checked it and it had only gone down by a small amount compared to when I left it on Tuesday. I then proceeded to tighten down the bolts attaching the tubo-pump to the zero-length reducer while it was under vacuum. This caused the pressure to drop down a few orders of magnitude.
  385   Wed Jun 26 15:33:41 2024 JonInfrastructureComputersNew workstation ws3 in 1129

Set-up of the first CDS workstation for 1129, ws3, is complete and the machine is ready for use. The login credentials are the same as the other lab machines.

All that now remains is to install a permanent cable tray for running the new Ethernet cables between the electronics rack and bench (they are currently dangling from the suspended lights).

Quote:
I have repurposed a spare Intel NUC to serve as the first of two planned workstations in 1129. Today I set it up with a fresh installation of Debian 12.5, assigned it the static IP address 192.168.1.15, and installed the LIGO CDS workstation packages. It is assigned the host name ws3. Temporarily, the mouse is borrowed from ws1 in 1119. We need to order another mouse as well as a 25-ft Ethernet cable for connecting the workstation to the 1129 switch, via the ceiling.

  384   Tue Jun 25 17:19:42 2024 LukeUpdateVACVacuum chamber leak checking
Currently our main leak is in the RGA line. We found this by closing the gate valve from the main volume to see if which side was leaking more. After identifying this we are pumping down the main volume to see how low it can go the third attachment was taken at 4:16 6/25/24. Pumping started around 3:15. We have not been able to find exactly which flange is leaking, but our guess is on the small blanks and where the cube attaches to the gate valve as seen in the second attachment. We will try a few more things and if the leak is not found/fixed we are planning on changing the configuration of the RGA line to remove the spherical cube, which we believe to be the problem. See fourth attachment for rough sketch of initial idea. We have all of the parts required and they are clean and double bagged in 1129. I have not yet made all the measurements to confirm that this design is feasible.
  383   Tue Jun 25 12:34:18 2024 ShaneUpdateCleanroomcleanroom 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
  382   Mon Jun 24 21:38:25 2024 PooyanInfrastructureComputersComputer server changes in 1119 and 1129

[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.  
  381   Mon Jun 24 14:28:51 2024 Cynthia UpdateInterferometer SimulationsSIS cavity with thermal effect
tried to run a cavity scan with thermal deformation and ring heater for ITM04 ETM08 (aLIGO mirrors). Not sure about the accuracy of the graph as there is some commands that still need to verified.
  380   Fri Jun 21 11:47:30 2024 LiuUpdateScripts/ProgramsCOMSOL simulation on alternative straightened heater elements design

In the previous post, we saw that for the heater element design with straight edges in replacement of the current eight-element ring-like design, it provides the similar Gaussian-like irradiance profiles, but with smaller power delivery efficiencies, as shown in the plot. This turned out to result in similar but less prominent thermal effects.

They only differ from the original baseline design by a source power rescaling, however, as shown in the plot, where we see the power-rescaled irradiance profiles for the straight edge designs are close to that for the ring design. The resulting temperature profiles and thermal distortions are shown in plot and plot. The thermal effects for the 16 straight-edge design with renormalized source power for instance are strikingly similar to that for the original ring design.

An alternative straightened heater element design has also been investigated with COMSOL FEA simulation. As shown in the attached, in this new design each heater element component is cut with multiple straight edges but remains connected, shown in the same colors (green and red). In the example, four straight edges are cut from each of the four heater components (4x4=16 edges in total). There is no spacing between the neighboring edges from the same element component, but the edges from different components are separated by 2mm, as can be seen in the attached. This new N-in-one straight edge design offers similar irradiance compared to that for the evenly-spaced N-sided regular polygon straight edge design with the same number of edges, as shown in the plot. It however has fewer heater components, four in this case, which makes it easier to implement in assembly and wiring, and less vulnerable to electrical and thermal shorts with their fewer heater element pins.

  379   Thu Jun 20 18:01:11 2024 JonInfrastructureComputersNew workstation ws3 in 1129
I have repurposed a spare Intel NUC to serve as the first of two planned workstations in 1129. Today I set it up with a fresh installation of Debian 12.5, assigned it the static IP address 192.168.1.15, and installed the LIGO CDS workstation packages. It is assigned the host name ws3. Temporarily, the mouse is borrowed from ws1 in 1119. We need to order another mouse as well as a 25-ft Ethernet cable for connecting the workstation to the 1129 switch, via the ceiling.
  378   Wed Jun 19 18:45:14 2024 LukeUpdate Vacuum chamber reassembly
[Luke, Aiden, Mohak , Tyler] On Tuesday we had the silver screws for the spherical cube shortened by a quarter of an inch so that they would fit into the gate valve. We then attached the spherical cube to the vacuum chamber. On Wednesday we finished assembling the RGA line and the main turbo pump.
  377   Mon Jun 17 11:47:46 2024 LiuInfrastructureGeneralTemporary cooling units for the labs
Below are the temporary cooling units installed last week in labs 1119 and 1129. They are the temp. replacement for the building AC system, which will be shut down during the Physics roof replacement.
  376   Fri Jun 14 13:32:13 2024 LiuUpdateScripts/ProgramsCOMSOL simulation on rectangular heater elements design

I have been looking at the feasibility of an alternative heater element design for FROSTI that replaces the original ring-like heater elements with n rectangular elements with straight edges. They form an n-sided regular polygon that could well approximate the original annular ring if n is large enough. This eliminates curved surfaces requirement for the heater elements, which was the source of the many month production delay for the prototype parts.

This design was implemented in COMSOL, shown in the attached. From the face on view, each element has a trapezoid shape with straight edges. The edges between neighboring elements are parallel, with a space of 2 mm in between them.

The ray tracing and thermal analysis obtained from COMSOL are shown in the attached pdf.

In particular, the 2D irradiance profiles were obtained from the ray tracing (so far from the front heating surfaces only). The 1D radial profiles were integrated and shown in the attached. The power delivery efficiency for the original ring-like heater element design is integrated to be roughly 65%, for comparison. The plot also shows the radial irradiance profiles for three different straight-edge designs, which correspond to 16 edges, 18 edges, and 24 edges. We see that with the straight-edge designs, the irradiance profiles stay in a good Gaussian shape. In addition, with a larger number of edges, the power efficiency increases, but is always less than the case for the optimized ring-like design.

The thermal distortions for the TM were also obtained from COMSOL, using the irradiance profiles at the TM HR. As shown in the attached, with the straight-edge design, the effects on the thermal lens OPD and the HR surface deformation are similar to the ring design, but with less severe edge roll-off for instance.

  375   Mon Jun 10 14:52:38 2024 TylerUpdateFLIRCIT FROSTI Analysis Update
[Tyler]

Upon further inspection, one adjustment was made to the FROSTI profile analysis: changing the transmission value of the ZnSe viewport. It was initially assumed that the viewport possessed an AR coating, which would bring the transmission into the 90% range. Without the coating, it drops to roughly 70%. Assuming no coating, the estimated delivered power was calculated to be 11.7 W. This is consistent with the estimated power given from the Hartmann sensor analysis, thus it is believed that the viewport indeed had no coating.

Quote:
[Tyler]

Attached below are the initial results of the CIT FROSTI testing analysis.

 

  374   Mon Jun 3 14:59:44 2024 CynthiaUpdateInterferometer SimulationsCreated cavity scan with LG modes
  373   Mon Jun 3 14:14:39 2024 TylerUpdateFLIRInitial CIT FROSTI Analysis
[Tyler]

Attached below are the initial results of the CIT FROSTI testing analysis.

  372   Mon Jun 3 09:24:48 2024 AidenUpdateVACVacuum Chamber Rendering
Here is a new render of the vacuum chamber that includes the 2.75 tee to place the Argon leak right next to the RGA. The conical reducer under the spherical cube was also replaced with a 4.5 blank. The height from the bottom of the blank to the bottom face of the chamber is 5.45". With the chamber now on 1" standoffs, we will need a support with a height of 6.45".
  371   Fri May 31 19:37:47 2024 LukeUpdate Vacuum chamber Disassembly
[Luke, Aiden, Jon, Michel, Tyler] Work done: On Tuesday (5/28) we removed the RGA line with minimal difficulty. On Wednesday (5/29) we removed the turbo pump, which had a few bolts that we needed to cut. We borrowed a dremel with ceramic blades from the machine shop to help remove some of the bolts. On Thursday we moved the vacuum chamber onto the floor to check and resecure the heating band on the bottom of the vacuum chamber. We then relocated the posts the vacuum chamber rests on closer to the end of the table and reinstalled the chamber. The post’s height was also reduced from 2in to 1in. Current state of vacuum chamber: The vacuum chamber is currently reinstalled in its new position. Some of the parts on the table will be used in the assembly of the turbo pump and RGA lines with the others being able to be moved to storage.
  369   Thu May 16 15:23:14 2024 ShaneUpdateCleanroomCleanroom 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
  368   Mon May 13 14:53:29 2024 PeterUpdateVLC UpdateVLC
VLC Update WEEK 7 attached below
  367   Mon May 13 14:48:27 2024 AidenUpdateVACNew Vacuum Chamber Design
I created a new model for the vacuum chamber based on the ideas from last week's meeting.

It should be noted that we can not have the zero length reducer and the gate valve on the same arm as they both have blind tapped holes. We need to decide if we want the gate valve or not as if we do, we will need to use the 3 inch long reducer.

Important Measurements:

From the back of the flange to the back of the RGA: 25.25 in

Height from bottom of the blank to the bottom of the chamber: 2.75 in

  366   Mon May 13 13:03:41 2024 TylerUpdateFLIRReadout Code Updates
[Tyler]

Some changes have been made to the FLIR readout code to help improve its functionality:

  • More accurate temperature readings than before due to updates in the calculation procedure. A bug was causing one of the parameters to not update correctly; this is now fixed.
  • Saved data now stored in HDF5 files rather than CSV.
  • User can now enable automatic data storage by specifying a collection interval (in minutes). The choice of manually saving data is still present if desired.
Below is an image of the graphical interface. This is an old screenshot. Visually, there is no difference between the older and newer version. The differences come from the list above, which help the user more reliably measure and store data for later analysis.

  365   Tue May 7 20:34:31 2024 shaneUpdateCDSfrosti MEDM screen update
[Luis, Shane] Here is the updated MEDM screen, with new orientation and updated labeling to reflect the actual positions of the heater elements. Note that indices start at T0 to be consistent with simulink model, though in the previous elog for the FROSTI layout the heater elements are labeled 1-8. Also, we finally learned how to take a screenshot on debian.
  364   Thu May 2 22:43:36 2024 TylerUpdateElectronicsRTD Readout Chassis Redesign
[Tyler, Jon]

Today the FROSTI RTD readout chassis underwent a redesign:

Instead of the original ratiometric method, which involved wiring the FROSTI RTDs in series, each element is individually powered by separate excitations. Each element additionally possesses its own reference resistor of 100 Ohm. Now, if an RTD experiences an electrical short, it should not affect the measurements of the others in sequence, as it had with the original design.

  363   Mon Apr 22 15:06:33 2024 Cynthia UpdateInterferometer Simulationscavity scan update
[Cynthia,Pooyan] Completed some simulations injecting 0-10th order modes. Some graphs will be used for the poster after some further titles, axis, and range adjustments.
  362   Wed Apr 17 15:07:04 2024 ShaneUpdateCleanroomCleanroom 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
  361   Mon Apr 15 15:25:10 2024 CynthiaUpdateInterferometer Simulationsprogress on simulation so far
  360   Mon Apr 15 11:51:03 2024 PeterUpdateVLC UpdateVLC
An update on the VLC project is attached below:
  359   Mon Apr 8 14:57:41 2024 Cynthia, PooyanUpdateInterferometer Simulationsperformed cavity scans for O4 O5, and coupled cavity
  358   Mon Apr 8 14:43:29 2024 PooyanUpdateInterferometer SimulationsSIS update single and coupled cavities
[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

  357   Sun Apr 7 13:42:51 2024 MichaelUpdateInterferometer SimulationsUpdate on status of gtrace project
[Pooyan, Michael]

After meeting and discussing the current state of our work with Prof. Fulda a few weeks ago, we have decided that the best next step for the gtrace project is its integration into finesse work. Our first step towards this integration involved creating a sequential beam trace in contrast to the previous non sequential gtrace simulations. A sequential beam trace not only allows for faster runtimes of the simulation (<1 second) but also allows for more direct reading of certain beam parameters (beam size, gouy phase, and angle of incidence). The sequential model was created alongside a yaml output which provides values of parameters, now including the angle of incidence on a mirror.

Last Monday, Pooyan gave a report to the Cosmic Explorer optical design team on the current state of our project and the ultimate goal of our work. During the same meeting another group working in the optical design team presented their own work with gtrace and optical design, focusing more on optimization of parameters based on desired beam sizes at each mirror. It might be a good idea to begin attempting to bring our individual projects together to allow for collaboration and further developments.

Currently, only the crab1 layout has a sequential trace model. Pooyan is currently working on creating a finesse model for crab1 to serve as a proof of concept for how gtrace could be integrated with finesse by providing useful values such as angles of incidence.

  356   Wed Mar 27 00:03:57 2024 PooyanUpdateComputersChimay relocation to Physics 1129

[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.

  355   Tue Mar 26 13:51:56 2024 TylerUpdateDAQRTD Parameter Calibration

Another re-fit, but this time the quadratic coefficient (beta) is set to 1.003e-6:

       R_0 (ohm)   Alpha (1/C)

RTD 0   79.7386   0.001863

RTD 1   78.6248   0.002359

RTD 2   81.3254   0.002211

RTD 3   74.6127   0.003509

RTD 4   80.6652   0.001988

RTD 5   78.5450   0.002127

RTD 6   77.0144   0.002268

RTD 7   83.0204   0.002288

Quote:
Refitted RTD calibration, neglecting quadratic term:

       R_0 (ohm)   Alpha (1/C)

RTD 0   79.3962   0.002031

RTD 1   78.2874   0.002530

RTD 2   80.9775   0.002381

RTD 3   74.2947   0.003684

RTD 4   80.3199   0.002157

RTD 5   78.2106   0.002297

RTD 6   76.6825   0.002438

RTD 7   82.6645   0.002458


Measurements taken can be found here. An uncertainty of 1 C was assumed for temperature.

Quote:
[Jon,Tyler]

We noticed that the RTD temperature readings given on the Cymac were off, and traced the issue to miscalibration in the relationship between the resistance and temperature of each RTD (Callendar-Van Dusen eqn). Below is the table of values inferred from independent measurements of temperature and resistance to rectify this problem. This data was then fitted to better determine the coefficients present in the temperature-resistance relation:

       R_0 (ohm)   Alpha    Beta

RTD 0   80.8674   0.001315   4.273e-6

RTD 1   79.5704   0.001887   3.7873e-6

RTD 2   81.7334   0.002014   2.1724e-6

RTD 3   74.3060   0.003677   3.6022e-8

RTD 4   81.1350   0.001761   2.3598e-6

RTD 5   77.9610   0.002423   -7.5192e-7

RTD 6   78.7980   0.001373   6.2909e-6

RTD 7   83.8616   0.001890   3.3529e-6

 

 

  354   Mon Mar 25 10:55:33 2024 TylerUpdateDAQRTD Parameter Calibration
Refitted RTD calibration, neglecting quadratic term:

       R_0 (ohm)   Alpha (1/C)

RTD 0   79.3962   0.002031

RTD 1   78.2874   0.002530

RTD 2   80.9775   0.002381

RTD 3   74.2947   0.003684

RTD 4   80.3199   0.002157

RTD 5   78.2106   0.002297

RTD 6   76.6825   0.002438

RTD 7   82.6645   0.002458


Measurements taken can be found here. An uncertainty of 1 C was assumed for temperature.

Quote:
[Jon,Tyler]

We noticed that the RTD temperature readings given on the Cymac were off, and traced the issue to miscalibration in the relationship between the resistance and temperature of each RTD (Callendar-Van Dusen eqn). Below is the table of values inferred from independent measurements of temperature and resistance to rectify this problem. This data was then fitted to better determine the coefficients present in the temperature-resistance relation:

       R_0 (ohm)   Alpha    Beta

RTD 0   80.8674   0.001315   4.273e-6

RTD 1   79.5704   0.001887   3.7873e-6

RTD 2   81.7334   0.002014   2.1724e-6

RTD 3   74.3060   0.003677   3.6022e-8

RTD 4   81.1350   0.001761   2.3598e-6

RTD 5   77.9610   0.002423   -7.5192e-7

RTD 6   78.7980   0.001373   6.2909e-6

RTD 7   83.8616   0.001890   3.3529e-6

 

  353   Sun Mar 24 11:50:37 2024 AidenUpdateClean &amp; BakeCal Tech FROSTI Parts
Bagged the FROSTI legs and feet after the conclusion of the clean and bake. They are double bagged and sitting in the flow bench.
  352   Sun Mar 24 11:49:27 2024 AidenUpdateGeneralFROSTI RGA Scan
Took RGA data 1 day after the conclusion of Bake 13. Bake 13 ended on Saturday March 23, the RGA data shown was taken on Sunday March 24. The scan shows that the FROSTI is very clean with no outgassing. The HC levels are at 25 e-10. The pressure in the chamber was also a 1.64 e-8 Torr.
  351   Thu Mar 21 16:56:42 2024 TylerUpdateDAQRTD Parameter Calibration
[Jon,Tyler]

We noticed that the RTD temperature readings given on the Cymac were off, and traced the issue to miscalibration in the relationship between the resistance and temperature of each RTD (Callendar-Van Dusen eqn). Below is the table of values inferred from independent measurements of temperature and resistance to rectify this problem. This data was then fitted to better determine the coefficients present in the temperature-resistance relation:

       R_0 (ohm)   Alpha    Beta

RTD 0   80.8674   0.001315   4.273e-6

RTD 1   79.5704   0.001887   3.7873e-6

RTD 2   81.7334   0.002014   2.1724e-6

RTD 3   74.3060   0.003677   3.6022e-8

RTD 4   81.1350   0.001761   2.3598e-6

RTD 5   77.9610   0.002423   -7.5192e-7

RTD 6   78.7980   0.001373   6.2909e-6

RTD 7   83.8616   0.001890   3.3529e-6

  350   Tue Mar 19 15:22:27 2024 AidenUpdateClean &amp; BakeFROSTI Legs Clean and Bake
[Aiden, Luke]

Cleaned and baked the Cal Tech FROSTI legs and showed Luke the procedure on how to clean parts.

  349   Tue Mar 19 10:55:30 2024 TylerUpdateFLIRIn-Air Optical Test
Below is an image I took using the FLIR just before leaving for the LVK meeting. The profile is roughly what we would expect (annular). Any distortions seen are likely from the screen not being completely parallel to the plane of the FroSTI (i.e. the screen slightly bends in various locations). Next step: In-vacuum test at CIT.
  348   Fri Mar 15 16:58:55 2024 AidenUpdateVACVacuum Chamber Frosti Testing
[Luke, Luis, Aiden] On Thursday, March 14 - Took preliminary RGA scans of the empty chamber to compare later on. Vented the chamber and placed the FROSTI into the chamber. Plugged in the DB-25 connectors into the feed through port and checked the connection to make sure there were no shorts before closing the chamber and starting the pumps again. On Friday, March 15 - The pressure in the chamber has come down to 7 e-6 torr. It seems to be coming down much slower despite the little time the chamber was left open for. This may be due to the FROSTI being out on the table for so long and a bake may be needed to bring the pressure down to near UHV.
  347   Wed Mar 6 09:57:52 2024 TylerUpdateTCSFROSTI Wiring

Upon finishing the FROSTI assembly last week, we ran into some electrical issues. An electrical short was found between two of the d-sub pins (2 and 8). It appears that the pins were somehow coming into contact with the aluminum surrounding them. This was causing the power supply to trip. The issue was seemingly fixed by adjusting the positioning of the cabling leading out of the reflector. When handling the device in the future, please make sure to keep the wiring as undisturbed as possible. The setup is rather fragile, and moving the cabling around could potentially reintroduce a short like this.

  346   Thu Feb 29 17:16:48 2024 ShaneUpdateCDSMEDM screen for FROSTI T/P readouts
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.
  345   Wed Feb 28 17:49:18 2024 TylerUpdateTCSFROSTI Assembly - Days 2-3
[Aiden, Jon, Luis, Luke, Michael, Tyler]

FROSTI assembly was completed today. The RTD and power wires were terminated at the DB-25 connectors and the legs were put on. It is currently placed in front of the stand-in test mass (~5 cm away). The FLIR has also been moved back to it's nominal position. As of now, it appears there are some shorts within the power cabling. This will be a focus of tomorrow's work.

Quote:
[Jon, Tyler, Luis, Luke, Mohak, Cynthia, Michael, Aiden]

FROSTI assembly began today. After a final set of RGA scans were taken, the vacuum chamber was vented and the reflectors were removed. The chamber was then resealed and pumped down again. 

Today we completed the installation of the Macor hardware and heater elements between the two reflector halves. Tomorrow we will route, bundle, and terminate the power and sensor cables. 

 

  344   Wed Feb 28 12:02:08 2024 TylerUpdateGeneralResistors for Heater Elements Update
Power Res (Ohm) RTD Res (Ohm)

Heater 1= 72.8; 80.6

Heater 2= 69.5; 80.8

Heater 3= 70; 83.2

Heater 4= 70.6; 78.7

Heater 5= 69.9; 80.6

Heater 6= 71.1; 78.2

Heater 7= 68.5; 76.8

Heater 8= 70.1; 82.8

Quote:
Power Res (Ohm) RTD Res (Ohm)

Heater 1= 73.6; 81.8

Heater 2= 70.4; 82.1

Heater 3= 71; 84.5

Heater 4= 71.5; 80

Heater 5= 70.5; 81.7

Heater 6= 72; 79.4

Heater 7= 69.2; 78.2

Heater 8= 71.1; 84.2

 

  343   Tue Feb 27 09:06:29 2024 Cynthia UpdateInterferometer Simulationscavity scan with higher order input laser
I performed a few cavity scan with the inputing laser with a different mode (not pure 00). For each laser I included a graph for just plotting the order with highest power (for example 1st order laser input the first plot only scanned for 1st order in that cavity), and I have also included a graph scanning for order 1-10.
  342   Tue Feb 27 03:26:28 2024 MichaelUpdateInterferometer SimulationsReverse aLIGO Layout Created in Gtrace
I've created the simulation for reverse aLIGO layout in gtrace. Attached are the desmos model and the output dxf file. From here Pooyan and I plan to create a brief report of our progress to the CE optical design group.
  341   Mon Feb 26 21:23:27 2024 JonUpdateTCSFROSTI Assembly - Day 1
[Jon, Tyler, Luis, Luke, Mohak, Cynthia, Michael, Aiden]

FROSTI assembly began today. After a final set of RGA scans were taken, the vacuum chamber was vented and the reflectors were removed. The chamber was then resealed and pumped down again. 

Today we completed the installation of the Macor hardware and heater elements between the two reflector halves. Tomorrow we will route, bundle, and terminate the power and sensor cables. 

  340   Mon Feb 26 15:15:39 2024 AidenUpdateGeneralVacuum Chamber Baking Update
Started Bake 12 on Wednesday Feb. 21 and turned the bake off on Saturday Feb. 24. This was a normal low temp bake with the PID controllers set to 110 degC.
  339   Sat Feb 24 08:53:38 2024 JonInfrastructureComputersMatlab upgraded to 2023b on Chimay
I upgraded Matlab on chimay to the latest stable release, 2023b. From some quick tests, it appears to be in working order. Let me know of any issues.
ELOG V3.1.3-7933898