ligo-ex ligo-ds
  Richardson Lab Experimental Log, Page 6 of 12  Not logged in ELOG logo
ID Date Authordown Type Category Subject
  128   Tue Jun 20 17:28:23 2023 PamellaUpdateElectronicsHeater system parts - Wiped
[Pamella]
    Heating system
    Wiping the heater system parts.
  • 04:37 pm: Started wiping the electronic device part for the heater system (HL101 Series Digital Benchtop temperature limit control).
  • 05:19 pm: Finished wiping the parts to the heater system (HL101 Series Digital Benchtop temperature limit control). I wiped the HL101 Series Digital Benchtop temperature limit control and I didn't bagged and tagged because we should install that soon.
  • 05:23 pm: I putted heater electronic device inside the cleanroom without the bag. Also the electronic device is near to the vacuum chamber and the other parts to heater system.
  • I attached the photo below.
  132   Fri Jun 23 15:47:06 2023 PamellaUpdateFLIRCollecting data - Moving horizontal and vertical on screen.
[Pamella]
  • 02:09 pm: Turned on the device (current on)
  • 02:42 pm: Started taking snap on position one (Reference point: 0,-0.062). Parameters:0.10A,1.5V,41.5C
  • I took multiplier snap on the same position for compare after on data analyzes. I just wanted one/two minute break between the snaps. I did that same for every position.
  • 02:55 pm: Started taking snap on position two (Reference point:-0.10,-0.062 ). Parameters: 0.10A,1.5v,43 C
  • 03:01 pm: Started taking snap on position three (Reference point:0.05 ,-0.062). Parameters: 0.1A,1.4V,42.8C
  • 03:07 pm: Started taking snap on position four (Reference point: 0.05,0.045). Parameters:0.10A,1.5V,43.6 C
  • 03:15 pm: Started taking snap on position five (Reference point: 0,0.045). Parameters:0.10A, 1.4V, 44.1C
  • 03:22 pm: Started taking snap on position six (Reference point: 0,0.045). Parameters: 0.10A,1.4V,43.3 C
  • We can see in the photos attached below than have some differences between every position so I should be starting analyzes on that.
  135   Tue Jun 27 15:18:26 2023 PamellaUpdateFLIRNew data collection
    [Pamella]
    Yesterday, I did a new data collection. I could get a better data in this time and I realized than I need use some angle on the reflector for got a better shot. I need do that because the FLIR camera just is able to get the triangle shape for complete if I keep exactly in same line for center point on the camera but for the data now I need move the refletor to go up and go down. So wasn't working very well if I keep the reflector without angle.
    Now I am using the refletor with a angle. In the more high part I turn the mask for look the table and in the lower part I turn the mask to look up. I attached a photo below for this configuration. Also the processes to get the data was the same than I using last time, the only diference is now I just moved the pillar after get data for high position and lower position for the same reference point on the triangle shape.
    Note: In most data it is impossible to keep the same parameter for current, voltage and temperature. Most have a small variation but not a big difference. For example: I got the temperature in the first position 46.8 °C and in the second position I got 47.1 °C, it's just an example. It's just so we know that we don't have the exact same parameters all the time. In my opinion this is not a problem because it is just a small variation.
    The process to get data
  • 09:35 am: Turned on the device (current on). I wanted for 30 minutes before start get data.
  • 10:05 am: Started taking snap on position one (Reference point: -0.10, 0.050). Parameters:0.11A,1.7V,46.8°C
  • I took four snap on the same position for compare after on data analyzes. I just wanted one minute break between the snaps. I did the same for every position.
  • 10:15 am: Started taking snap on position two (Reference point:-0.10,-0.050 ). Parameters: 0.11A,1.7V,47.1° C
  • 10:22 am: Started taking snap on position three (Reference point:0.00 ,0.050). Parameters: 0.11A,1.6V,48.1°C
  • 10:26 am: Started taking snap on position four (Reference point: 0.00,-0.050). Parameters:0.11A,1.6V,48 °C
  • 10:32 am: Started taking snap on position five (Reference point: 0.05,-0.050). Parameters:0.11A, 1.6V, 48°C
  • 10:37 am: Started taking snap on position six (Reference point: 0.05,0.050). Parameters: 0.11A,1.7V,47.6 °C
  • We can see in the photos attached below every position also I am working in the analyzes.
  139   Fri Jun 30 15:57:28 2023 PamellaUpdateFLIRData and python code update
    [Pamella]
    Updates: Problems with the emission intensity and python code.
  • Yesterday I was working on get data from FLIR reflector but unfortunately we got some problems:
    1. I realized than if I move the reflector a to left or right the screen doesn't get data very well(I attached a photo below). This is a problem because our idea is have the same type of emission every part on screen. Tyler and I worked to tried fix that but don't had success.
    2. Dr. Richardson gave me the idea to move the FLIR camera to left or right (The same happens if I move up and down) and keep the refletor on the same position every time but unfortunately we got the same problem, the screen doesn't get data very well(I attached a photo below). Now I am working to tried fix that.
  • Also I was able to work on the code to isolate the triangle shape for analyzes, I attached the image for that below.
  140   Fri Jun 30 16:43:14 2023 PamellaUpdateFLIRUpdates: Small moving the FLIR camera
[Pamella]
    Today, I was able to make some adjustments to the FLIR camera angle, suggested by Dr. Richardson, and we got small possible movements keeping the same pattern in the shapes of the triangles. I have attached photos below. I was able to move left and right as well as up and down and it worked in four points that I marked on the table.
    The only problem is that it only worked on a part of the screen, if I try to place it farther to the right or to the left, we are back to the same problem as yesterday.
  143   Mon Jul 3 18:38:13 2023 PamellaUpdateFLIRFLIR project
[Pamella]
  • I was able to work on the python code to do analysis on the FLIR-Reflector data.
  • I could plot images of total area (Tyler help me on that) with csv file and also could have isolation area for triangles. I have attached examples below. Just for now the images are of different data, so there are some differences in the shapes.
  • I'm working on getting a complete analysis code to work with the different positions of the triangles and to be able to do out the statistical analysis.
  • Also we keeping have problem to get good data if when we move the camera or the reflector on horizontal or vertical position. I am working a some ideas for that.
  144   Tue Jul 4 15:35:38 2023 PamellaUpdateFLIRFLIR - reflexion problem
[Pamella] I was testing all the positions we need to cover when moving the FLIR camera or the reflector. I tried to find out more about the problem so I tested the position without the mask, just with the old bridge and I got the same problems, in the middle of the screen we have a very good image but if we move we have the visualization problem and we don't see the reflection very well (intensity, emissivity) in FLIR. For this test I used very low current (0.04 A) for keep everything safety. I also think that problem is not in the focal point of the reflector because we can see very well in the center of the screen, but maybe it is because in the parabolic reflector the reflection in the focal point is "extremely" straight, so for you to see the reflection in this point you need keep close to the middle of the screen, to see around the reflector, at the extremes, we need to change the position for the cable or the light to "change" how the flashes of light reflect and thus achieve exactly the position on the camera. It is something like the sketch/ photo attached below.
  149   Thu Jul 6 18:03:19 2023 PamellaUpdateFLIRFLIR project - New configuration
[Pamella]
    Cao suggested using the project without the reflector and mask because in this case we probably got good images around the screen. So I started this yesterday and today I started to get some data to see the stabilization position and check how the parameters fluctuated. I was looking and taking snaps for an hour and a half. I'll repeat this one more time to make sure we have enough data to do analysis.
    To do: The next step is to start collecting data by moving the camera FLIR and covering all six positions on the screen (2x3). Also Aiden is on hand to help and is going to make a new 3D print bridge to have good heater support.
    I attached a image for the new configuration below and a snap data.
  151   Sat Jul 8 14:26:17 2023 PamellaUpdateFLIRData with the new configuration without the mask and reflector.
[Pamella] I started collecting data by moving the camera FLIR and covering all six positions on the screen (2x3). I was looking and taking snaps for more than one hour and a half. I'll repeat this one more time to make sure we have enough data to do analysis. I attached snap data below. This images is processed on python code.
  157   Fri Jul 14 16:49:42 2023 PamellaUpdateFLIRNew bridge and calibration data
[Pamella]
    Aiden 3D printed a new bridge for the heater and I installed the new bridge yesterday.
    I started collecting data to plot a calibration with the heater. I'm doing measurements with current and the thermocouple (thermometer) to compare with FLIR measurements and have a good calibration.
  158   Sun Jul 16 15:21:56 2023 PamellaUpdateGeneralGeneral update about some problems in the lab.
[Pamella]
    General information about the lab facility.
    1. Changed sticky floor mats, because close to entrance the cleanroom, both sticky floor had a many died ants on top.
    2. The light on top of the internet cable bridge is burned out.. I just saw this today but I am not sure if was like this before.
    3. The ant bait traps seem very efficient and right now only a few ants are running around in the lab, most are dead in the bait traps, so probably in a day or two we can change those bait traps.
  159   Mon Jul 17 11:46:24 2023 PamellaUpdateFLIRThermocouple plot.
[Pamella]
  • I collected data to plot a calibration with the heater. I took measurements with current and temperature (the thermocouple - thermometer) to compare with the FLIR measurements.
  • I made a plot with this data and we can see how temperature vs current behaves. Note: This data I measured manually.
  163   Tue Jul 18 16:04:26 2023 PamellaUpdateFLIRSetup FLIR with black wall (black body)
[Pamella]
  • Today I tried get data the heater with the black screen but doesn't looks possible have just one "energy" point straight to FLIR camera. Tyler and I tried different current and temperatures but keep very bad data. I attached a snap below.
  • I attached a photo about the new setup below. The FLIR is in the most close point possible/safety with the heater. The heater is very close to the black wall but is not touch the screen so is safety.
  164   Tue Jul 18 16:12:27 2023 PamellaUpdateFLIRThermocouple plot.
  • I noticed that these measurements have some issues with the weather on different days. We can see in the photo attached below how different the temperatures are on different days, I took the data with the same procedure every day, but we can see the differences between them.
  • To Do: I will do a new data collection using FLIR and thermocouple at the same time to plot comparison between both.

Quote:
[Pamella]
  • I collected data to plot a calibration with the heater. I took measurements with current and temperature (the thermocouple - thermometer) to compare with the FLIR measurements.
  • I made a plot with this data and we can see how temperature vs current behaves. Note: This data I measured manually.

 

  165   Tue Jul 18 16:35:06 2023 PamellaUpdateFLIRPlot-Data with the new configuration without the mask and reflector.
[Pamella]
  • I was able to plot the first graph for a result between the six different positions on the screen, for now we can see the behavior of the heater temperature in a Gaussian graph with combination data between the six files.
  • To do: Tyler gave me some ideas today to improve the plot. So I'm going to change the code to have insulation on the values for just the heater ("insulation") and I'm going to plot after this insulation data as well I'm going to get more data and compare with more data for the same position.
  • I was using the data than I got last week and I shared on Elog (151) and we can see on this quote

Quote:
[Pamella] I started collecting data by moving the camera FLIR and covering all six positions on the screen (2x3). I was looking and taking snaps for more than one hour and a half. I'll repeat this one more time to make sure we have enough data to do analysis. I attached snap data below. This images is processed on python code.

 

  167   Wed Jul 19 19:10:31 2023 PamellaUpdateFLIRData plot FLIR and updates.
[Pamella]
  • Today I was able to plot a graph for the isolation point on the center of the heater. I got data from six different positions on the screen (I shifted the all coordinates). I extracted the data for the center point and plot the Gaussian with this extracted data for temperature. I attached the all plots below
  • Also I took a snap using the black wall and with the heater at 120.1 C (0.30 A) try to have less noise but we can see this is not very good. At this temperature, we have noise on the top and I don't understand why because the heater is not in this location. I attached a snap below.
  169   Thu Jul 20 21:00:23 2023 PamellaUpdateFLIRData plot FLIR and updates about the black body
[Pamella]
  • Today I got more data to plot the Gaussian. So I took more snaps in each position for the six different spots than we be using to have a better calibration of the FLIR collected data. I attached the new plot below. Also, I did the same plot for each region as on the Elog 167 but I have more than 20 pics because I was using a big number of data so I just attached one example below.
  • To access the Elog, click here.

  • Also I think we have some real (non-ideal) heat diffusion by the screen and not noise like Dr. Richardson suggested. I was testing today and we can see the first pic before the start heater source turns on, the second pic is at 120.2 C (0.31A) with the heater on and the last pic is after the heater source cooled back down to room temperature. Just in the second pic, we have a strong spot on the top, so it looks like a non-ideal diffusion.
  181   Fri Jul 28 18:03:07 2023 PamellaUpdateFLIRFinal plot - FLIR
[Pamella]
    1. I was able to plot the final result with the data to the heater. I attached below the "3Combined_HighTemp_Gaussian_Plot." in this plot we can see better behavior on the Gaussian compared to the plot in ELOG 169, I was using the same data but with a different approach. On the ELOG 169, we have the center point isolated data and this new plot is the temperature more than 70 C isolated because we have a very good heater temperature distinguish do background. For the all data I got I was using a power current of 0.20A. To get the data I waited for 30 minutes until the heater became stable and after that, I started to take snaps, I took more than one snap for each one different 6 positions on the screen, and We can see the positions on ELOG 167.
    2. Also I attached the calibration plot ("calibration_plot") between the measurements with the FLIR camera and thermocouple and we can see looks good if we compare the final plot.
    3. For better analyses I attached a plot of the calibration line on the Gaussian plot.
    4. To do: I will finish the final report.
  536   Mon Mar 10 21:13:12 2025 NathanUpdateVLC UpdatePDH Lock Progress and Next Steps
Progress update: Photodiode is set up, need to set up DC bias tee, EOM has 400-600nm wavelength range with a resonance frequency of 0.1-100MHz. Additionally need to connect the DC bias to SR560, put it in low pass, then connect to the function generator and connect it to oscilloscope to observe. Once everything looks good and working, need to connect the driver and we can start actuating on the cavity ETM.
  537   Mon Mar 10 21:32:29 2025 NathanPhysicsElectronicsBeam Profiling and PBS Measurements
Beam wasn't diverging, however maybe was about to diverge when measurements stopped? Will discuss the PBS measurements and how the voltage changed due to the wave plate.
  551   Tue Apr 8 20:04:35 2025 NathanUpdateVLC UpdatePDH Lock Progress
Connected the DC bias and mixer. Need to connect signal generator now to RF Amp and mixer, and also need to connect power supply. After that will see if I can get a detection on the oscilloscope and if so will set up the driver. [Photos attached]
  560   Tue Apr 22 13:00:04 2025 NathanUpdateVLC UpdatePhotodiode signal check and additional signal check due to 20Mhz signal and amplifier
In general, photodiode was able to achieve signal. Below are the voltage signals and frequency measurements of the photodiode with the dc bias and amplifier connected to the EOM (Vpp = 2mV for first and Vpp= 1 for second). Also I need assistance in using the PZT driver.
  317   Tue Feb 6 22:40:25 2024 MichaelUpdateScripts/ProgramsLong Crab 1 Design Created In Gtrace
Worked on and completed the python code for the simulation of the Long Crab 1 layout for Cosmic Explorer basing off of Pooyan's original work with the Crab 1 layout. From here I'll look into creating the shoelaces layouts.
  322   Tue Feb 13 04:05:32 2024 MichaelUpdateInterferometer SimulationsShoelaces 1 Layout Simulated in GTrace
I've worked on and have completed a first simulation of Cosmic Explorer's Shoelaces 1 layout. This is based off of Pooyan's original work with Gtrace much like the Long Crab 1 layout I worked on last week. This layout will allow me to quickly created the alternate shoelaces layouts. I've included an image of the dxf, and a desmos model for reference.
  334   Wed Feb 21 23:15:07 2024 MichaelUpdateInterferometer SimulationsLong Shoelaces 1 Layout Created in Gtrace and Fixed Ghosting in Beamsplitter
I have created the long shoelaces 1 layout for cosmic explorer using gtrace, a slight modification from the shoelaces 1 layout design. I also modified the simulation code slightly to remove ghosting effects in the beamsplitter. Originally the python code specified that the HR and AR sides of the beamsplitter both have the same transmission/reflection. I modified this to the ideal case of: Refl_AR = 0, Trans_AR = 1. I have attached two images below to show the before and after effect of this modification.
  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.
  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.

  397   Mon Jul 8 12:26:10 2024 MichaelUpdateInterferometer SimulationsMinimizing Astigmatic Effects in the SRC of LIGO
This is the first look and analysis of the effects of astigmatism in the aLIGO optical layout which can lead to mode mismatch and therefore increased losses into higher order modes. Specifically I am currently looking at measuring the effect of changing the radii of curvature of the SRC mirrors https://docs.google.com/presentation/d/1qhIehqyNukg4g8S2fqfQZz83yr9aB76tEa6fn2J-TrM/edit?usp=sharing
  409   Mon Jul 15 15:52:40 2024 MichaelUpdateInterferometer SimulationsaLIGO locking with varying SRC mirrors and measuring mode mismatch
  Draft   Sun Aug 4 09:01:01 2024 MichaelUpdateInterferometer SimulationsUpdate on SRC Mode Mismatch Analysis
An update on my analysis to minimize mode mismatch/scattering by introducing toroidal mirrors to the SRC.
  436   Mon Sep 9 12:36:45 2024 MichaelUpdateInterferometer SimulationsUpdate on Analysis of Mode Mismatch Minimization in A#
I have taken a closer look at the solution curve in the mirror parameter space which I have searched, focusing on the "resilience" of specific points, with the plan to analyze how certain conditions of the interferometer change as we move along this solution curve.
  482   Mon Dec 2 00:11:23 2024 MichaelUpdateInterferometer SimulationsStatus Update on Toroidal Mirrors Project Work
As it has been significant time from my last update on this project, I compiled a few notes about what I have been working on, current issues, and my future plans. The past few weeks have been focused on me attempting to obtain a reliable symbolic expression for mismatch. This is important going forward as it allows us to determine optimal points in the parameter space and the surrounding behavior efficiently without significant computational cost. However this been quite difficult since I've encountered some fundamental discrepancies in the way values like the ABCD matrix and q-parameters are calculated/returned in Finesse. Since I have yet to resolve this, I'm focusing on next steps in developing tools for statistical simulations.

Update Slides

  523   Tue Feb 25 01:37:00 2025 MichaelUpdateInterferometer SimulationsUpdates and Current Next Steps for Toroidal Mirrors Project
Since the previous discussion of this project, I've worked on building finesse models to verify mathematical results which model the astigmatism in a two mirror system which we attempt to minimize. This left us with a single condition for an output non-astigmatic beam. However, as can be seen in finesse simulations, there does exist other configurations which have a negligibly small astigmatism, which we may want to consider. Below I've attached the link to my overleaf project which has some updated information which I plan on discussing.

https://www.overleaf.com/project/67968921426e61d5b2fd8c96
  548   Tue Apr 8 00:17:01 2025 MichaelUpdateInterferometer SimulationsSqueezing Performance Graphs for Case With and Without Toroidal Mirrors in LIGO
I've created some graphs for the frequency dependent observed squeezing level in LIGO for both the nominal case and the case where we include toroidal mirrors, giving some interesting results. https://docs.google.com/presentation/d/1RBr47hNaxFTdGrwys5ZCUEUOgVOVHmZ2B_5EQwY62IY/edit?usp=sharing
  556   Mon Apr 21 16:56:42 2025 MichaelUpdateInterferometer SimulationsFixed Observed Squeezing Curve for Toroidal Mirror Case
We've resolved the issue with the observed squeezing curve for the toroidal mirror case showing worse performance at lower frequencies and better performance at higher frequencies compared to the nominal case. This issue was caused by the beam parameter at the squeezer being fixed before changing the radii of curvature of the mirrors. This has been changed to be fixed after changing the mirrors, and we see an improvement in the toroidal mirror case.
  571   Tue May 6 13:07:34 2025 MichaelUpdateInterferometer SimulationsInitial Convergence Plots for Toroidal Mirrors Project
  582   Mon May 26 23:24:33 2025 MichaelUpdateInterferometer SimulationsInitial Monte Carlo Simulations for Toroidal Mirrors Project
I've run an initial Monte Carlo simulation for statistical comparison of toroidal mirrors for the dual FROSTI TCS case. Below is the link to the slides.

slideshow

  541   Sun Mar 23 15:39:06 2025 Luke JohnsonUpdateScripts/ProgramsRingheater Location optimization
Attached are some plots that show a new parameter sweep with a finer mesh then before. I have also been able to get a heatmap of power of HOMs in a very simple finesse model.
  543   Mon Mar 31 11:26:45 2025 Luke JohnsonUpdateScripts/ProgramsHeatmaps of power delivery performance
These plots show the required temperature to release 100W of power and the efficiency of a particular configuration with half-width w and distance away from the barrel z. I want to add to these heat maps a limit line that has restricts the proximity of the reflectors from the barrel.
  405   Mon Jul 15 13:30:49 2024 Luke UpdateVACProblem with 2.75" to 1.33" zero length reducer
Last Friday while checking the depth of the ZLR I got one of the screws stuck. Today I tried a couple things to get it out. First I tried a few different pliers to be able to grip lower on the screw this didn't work. So I switched to the other method of drilling a small hole to see if maybe the threads would pull away from the walls of the hole a bit. This kind of worked as seen in the picture below I was able to remove most of the screw but there is a bit still stuck which I was not able to remove and I didn't want to use a larger bit for fear of damaging the tapped hole.
  423   Mon Aug 12 16:35:30 2024 Luke Update Ringheater modeling Update
  435   Fri Sep 6 14:34:52 2024 Luke UpdateVACHeating tape work

On the 5th I had tried to start baking the vacuum chamber however certain parts of the chamber were getting too hot and causing the controllers to shut off. So I turned them off so that the next day I could rearrange the temperature probes. I then on the 6th set them up so that instead of overshooting the temperature they would be a little low in places.

After being left over night the cooler parts of the vacuum chamber got much closer to the desired temperature of 120C.

Here is a table of the temperatures of the sections of the chamber. Note: After these measurements were taken the PID controllers were set to 125C.

Location   Temperature (C)
Lid (PID controller 1 emergency shutoff) 108
Barrel lower (PID controller 1) 120 
Barrel upper (PID controller 2 emergency shutoff) 118
RGA volume (PID controller 2) 120

Here is a table of temperature of the flanges that have electronics.

Electronics Temperature (C)
Pressure gauge (Main volume) 79
Main turbo pump 64
RGA 51
Pressure gauge (RGA volume) 55
Cal leak 47
Mini turbo pump 50
Pirani gauge 45 

Other temperatures of note:

The optical table was about 38C

The cleanroom was around 33C (~91F)

  452   Wed Oct 2 12:05:42 2024 Luke Update Ringheater modeling Update

Power point slides

  Draft   Wed Oct 23 12:33:54 2024 Luke Update Zernike calculation update

PowerPoint slides new

PowerPoint slides older

  471   Wed Nov 13 14:06:00 2024 Luke UpdateGeneral 

slides

  472   Thu Nov 14 10:46:20 2024 Luke SummaryCleanroomCleanroom cleaning

 

[Luke, Luis, Michael]

cleaning cleanroom and particle count

  • 8:30 am: started particle count
    • zone 3:
      • 0.3 u: 1195
      • 0.5 u: 177
      • 1.0 u: 132
    • zone 4:
      • 0.3 u: 619
      • 0.5 u: 0
      • 1.0 u: 0
  • 9:00 am: began surface check and wipedown, including softwalls
  • 9:35 am: started vacuuming the floor
  • 9:43 am: finished vacuuming the floor
  • 9:45 am: started mopping the floor
  • 9:55 am: finished mopping the floor
  • 9:56 am: started cleaning the buckets
  • 10:00 am: started mopping with IPA wipes
  • 10:05 am: finished mopping with IPA wipes
  • 10:20m: started particle count
    • zone 3:
      • 0.3 u: 2213
      • 0.5 u: 398
      • 1.0 u: 0
    • zone 4:
      • 0.3 u: 1150
      • 0.5 u: 177
      • 1.0 u: 44
  474   Tue Nov 19 17:10:34 2024 Luke UpdateVACLeak check

Chamber temperature: 23C

Chamber Initial Pressure: ~1.8e-8 main, ~3.5e-8 rga

Did another leak test after monday's work to check how the seal was holding up initial leak was 5.5e-9. I then tried to tighten the bolts a bit more the leak rose to 1.9e-8 about a factor of 4 change.

I checked another flange to confirm that I was preforming the test properly. I measured the elbow to pressure sensor to be 2.2e-11 aproximatly what it was earlier in the month (1.9e-11). 

I ran another isolation test. It is still exponetial. Graph attached.

Thoughts:

I belive at this point that it is a knife edge issue when replacing the gasket I checked both flanges and the new gasket. The tp knife edge seemed perfectly fine, the gasket had very minor scratches, and the reducing cross had very small imperfections on its edge. 

We may want to try and use the liquid sealant or get annealed gaskets for 4.5"

  478   Wed Nov 27 12:27:45 2024 Luke SummaryVACSummary of vacuum work

[Luke, Luis]

Update of current state of vacuum chamber

Current temp: 24°C

Current pressure: Main 1.77e-8, RGA 5.3e-9 [torr] (Gate valve open)

Summary of recent work-->

To try and reduce the leak in the turbo pump by reducing cross-connection, we replaced the copper gasket. This made no improvement to the leaks.

Initially: 1.9e-9 --->

Left side: 1.33e-9, Right side: 3.37e-9 (Gate valve open)

This is still a significant leak. We have tried to tighten the bolts further, but they are as tight as reasonably possible. 

Things of note: While examining the knife edges, we found some very slight imperfections on the reducing cross's flange as seen in 474. This could be the source of our leak. We have replaced this gasket 1-2 times already and consistently have a slight leak. This imperfection is on the right side of the flange, which would be consistent with the measurements above. 

Unless we want to use the liquid sealant or replace the gasket with an annealed gasket, we could try baking the system again, as this allowed us to reach UHV in the main volume before. It also allowed us to pass the RGA scan, which we are currently failing. (see attached)

  480   Wed Nov 27 16:23:58 2024 Luke UpdateVACStarted bake

[Luke, Luis]

The vacuum chamber is currently baking. 

We stepped up to 125°C by increments of 30°C starting at 60°C. Everything went fine. After about 20 minutes of the PID controllers being set to 125°C, the flange closest to the RGA was 38°C, so we left it connected. 

Current state as of 4:15:

The gate valve is open, and the filament of the RGA is on.

The temperatures are as follows:

PID right barrel upper: 105°C,  RGA volume: 125°C

PID left barrel lower: 125°C, Lid: 82°C

The lower temperatures should climb as the whole system heats up. 

I will come in Saturday afternoon to turn them off so that we can look at the pressures on Monday. 

  483   Mon Dec 2 13:35:45 2024 Luke UpdateGeneralClean and bake of Viton O-rings

[Luke, Luis]

We couldn't access the bake log on the wiki. (see attached) So we looked in the documentation provided on the DCC to find at what temperature to bake the Viton O-rings. We found that we should bake Viton at 180°C for 24 hours. 

So we sonic-washed the O-rings, dried them, and then put them in the oven set to the following:

100°C in 15 minutes

100°C for 30 minutes

180°C in 30 minutes

180°C for 24 hours

30°C in 2 hours

 

Other things of note:

We refilled the water container as it was running out.

The nitrogen used to dry the clean and baked objects is now critically low.

The helium used in leak testing is also quite low (~400 psi).

 

Regarding the vacuum chamber:

I reattached the pressure gauges to the chamber and gave them about an hour to stabilize. They read out main 8.7e-9, RGA 2.6e-9. Please note these pressures should lower more as we only stopped baking on Saturday afternoon. 

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