• 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.

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.

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.

Update Slides

slideshow

Simulating how point absorber defects on Advanced LIGO mirrors affect cavity performance by modeling a 4km LIGO-like arm cavity with a point absorber fixed at 5cm off-center on the ITM. In this simulation, displaced the laser beam across a 21×21 grid while calculating the deformation, then measuring the resulting power loss in the cavity (~283W circulating power).

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.

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

Other temperatures of note:

The optical table was about 38C

The cleanroom was around 33C (~91F)

Power point slides

PowerPoint slides new

PowerPoint slides older

slides

[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

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"

[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)

[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. 

[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. 

[Luke, Tyler, Cynthia, Shane, Michael]

Summary of Cleaning Activities:

We began cleaning Room 1119 at 2:00 PM.

At 2:30 PM, we moved to Room 1129 and continued cleaning.

Cleaning tasks included wiping down dust-collecting surfaces and vacuuming the floors.

Once the labs were clean, we proceeded to the cleanroom. 

• Wiping down surfaces and soft walls
• Vacuuming, mopping the floor, and finishing with IPA wipes

Particle Count Measurements:

• Pre-cleaning (2:30 PM):
  • Zone 3:
    • 0.3 µm: 973
    • 0.5 µm: 354
    • 1.0 µm: 132
  • Zone 4:
    • 0.3 µm: 486
    • 0.5 µm: 177
    • 1.0 µm: 0
• Post-cleaning (4:10 PM):
  • Zone 3:
    • 0.3 µm: 619
    • 0.5 µm: 132
    • 1.0 µm: 0
  • Zone 4:
    • 0.3 µm: 397
    • 0.5 µm: 0
    • 1.0 µm: 0

[Luke, Liu]

Over the winter break I have been working on this desmos toy model of the Frosti. There are still a few rough spots but I belive that it is a good visual representation of a 2D slice of the frosti. 

Here is a quick update on some of the things I have been working on regarding my project. 

[Luke, Cece, Luis]

Particle Count Measurements:

• Pre-cleaning (12:15 PM):
  • Zone 3:
    • 0.3 µm: 1325
    • 0.5 µm: 265
    • 1.0 µm: 0
  • Zone 4:
    • 0.3 µm: 618
    • 0.5 µm: 132
    • 1.0 µm: 44

• Started Cleaning (3:20 pm)
• Finished Cleaning (4:20 pm)

• Post-cleaning (4:35 PM):
  • Zone 3:
    • 0.3 µm: 1106
    • 0.5 µm: 221
    • 1.0 µm: 0
  • Zone 4:
    • 0.3 µm: 530
    • 0.5 µm: 44
    • 1.0 µm: 0

[Luke, Luis]

The vacuum chamber is currently baking. 

We stepped up to 120°C by increments of 30°C starting at 60°C. We took about an hour break at 90°C to let the temperatures equilibrate.  

Current state as of 12:20:

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

The temperatures are as follows:

PID right barrel upper: 113°C,  RGA volume: 120°C

PID left barrel lower: 121°C, Lid: 114°C

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