Fri Jul 5 14:12:32 2024, Liu, Update, Interferometer Simulations, CE BS Mechanical Resonances 
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The butterfly and drumhead mechanical modes for the aLIGO BS were calculated in COMSOL. The resonant frequencies for the two acoustic modes are 2.45
kHz and 3.61 kHz, matching the results in reference
for instance.
For a quick projection for the resonant frequencies going from aLIGO to CE, the height and width of the BS are increased assuming |
Fri Jul 5 14:23:13 2024, Liu, Update, Interferometer Simulations, Engineering drawings for straight edge heater element designs for FROSTI
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Step files and engineering drawings for the straight edge heater element designs have been created in COMSOL and SolidWorks. They are available in the group
Git
Repo. With those, we will initiate a discussion with the ceramics supplier for an estimate of the feasibility and benefits of the straight edge element |
Mon Jul 15 09:36:44 2024, Liu, Update, Interferometer Simulations, ETM Profile Optimization for FROSTI
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This is to optimize the FROSTI heating profile for ETM, by minimizing the residual RMSE of the HR surface deformation after the beam size weighted curvature
is removed by the current RH. The parameters of the profile being explored are the location, width, and total power for the Gaussian Annulus. As shown
in the attached series of plots, the optimal location is 9.9 cm, with a width of 7.7 cm, and a total FROSTI power of 12.7 W (for 1 W of Gaussian beam absorption). |
Mon Jul 29 12:18:52 2024, Liu, Update, Interferometer Simulations, Update on FROSTI O5 ETM profile optimization
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| Update on FROSTI O5 ETM profile optimization is attached. |
Mon Jul 29 12:20:56 2024, Liu, Update, Interferometer Simulations, Update on wavefront actuation with astigmatically driven RH for CE
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| Update on wavefront actuation with astigmatically driven RH for CE is attached. |
Mon Jul 29 12:23:10 2024, Liu, Update, Interferometer Simulations, Update on mechanical resonances of CE BS with stiffener ring
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| Update on mechanical resonances of CE BS with stiffener ring is attached. |
Wed Oct 2 14:49:59 2024, Liu, Update, , FROSTI ETM actuation
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Proposed FROSTI ETM actuation on the HOM7 resonance.
Animation |
Wed Oct 16 14:13:31 2024, Liu, Update, , FROSTI with non uniform absorption scattering sources
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| Slides |
Wed Nov 6 13:48:55 2024, Liu, Update, Interferometer Simulations, QN modeling update
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| Slides |
Tue Apr 1 11:47:08 2025, Liu, Update, ,
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Tue Apr 8 10:47:10 2025, Liu, Update, General, Test Mass Thermal State Decoder Update
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Tue Apr 15 11:09:37 2025, Liu, Update, FLIR, Test Mass Thermal State Decoder Update with robustness study 
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Thu Apr 17 12:12:29 2025, Liu, HowTo, Interferometer Simulations, Preventing Thread Contention in Multiprocessing with Finesse and Cython
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Avoiding Thread Contention When Using Multiprocessing with Finesse
and Cython
When running Monte Carlo simulations or other computational
workloads, it's common to use Python's ProcessPoolExecutor |
Tue Apr 22 11:04:31 2025, Liu, Update, Interferometer Simulations, Test Mass Thermal State Decoder Update with Interferometer Operation
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Tue Apr 29 10:59:25 2025, Liu, Update, Interferometer Simulations, Test Mass Thermal State Decoder with Updated Comparison Cases
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Tue Jun 24 13:47:58 2025, Liu, Update, Interferometer Simulations, Alternative FROSTI A# optimization approach
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| Alternative FROSTI A# optimization approach |
Tue Jul 29 11:27:57 2025, Liu, Update, Interferometer Simulations, Multi-ring FROSTI optimization for A#  
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Tue Aug 5 12:21:04 2025, Liu, Update, Interferometer Simulations, FROSTI A# optimization
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| A# multi-ring FROSTI optimization |
Tue Aug 12 12:16:21 2025, Liu, Update, Interferometer Simulations, Multi-ring FROSTI optimization for A#
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| Multi-ring FROSTI optimization for A# with static polishing |
Tue Aug 12 13:32:43 2025, Liu, Update, Interferometer Simulations, 
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| Differences in Fused Silica parameters. |
Tue Aug 26 12:14:24 2025, Liu, Update, Interferometer Simulations, Multi-ring FROSTI design for A# with ring heater optimization
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| Multi-ring FROSTI design for A# with ring heater optimization |
Tue Sep 2 12:41:33 2025, Liu, Update, Interferometer Simulations, Multi-ring FROSTI design for A# with ring heater optimization
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[Tyler, Liu]
Ring heater optimization, continued |
Tue Sep 2 18:33:38 2025, Liu, Infrastructure, General, New lab room 1125 layout and measurement
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Action items for facilities
Ceiling lights replacement
Fume hood cleaned and refurbished
Sink countertop cleaning
Floor cleaned and waxed
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Tue Sep 9 12:13:38 2025, Liu, Update, Interferometer Simulations, Multi-ring FROSTI optimization for A# with grid search
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| Multi-ring FROSTI optimization based on IFO metrics for A# with grid search |
Tue Sep 16 12:18:09 2025, Liu, Update, Interferometer Simulations, Grid search optimization for single-ring FROSTI
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| Grid search optimization for single-ring FROSTI |
Tue Sep 23 12:39:29 2025, Liu, Update, Interferometer Simulations, Multi-ring FROSTI optimization for A#
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Tue Sep 30 12:26:15 2025, Liu, Update, Interferometer Simulations, FROSTI optimization for A#
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Thu Oct 9 12:18:14 2025, Liu, Update, Interferometer Simulations, Multi-ring FROSTI optimization for A#
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Thu Oct 16 10:31:20 2025, Liu, Update, Interferometer Simulations, Multi-ring FROSTI optimization for A# 
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| Two-ring FROSTI grid search with 4D parameter space search and visualization |
Thu Oct 23 10:07:51 2025, Liu, Update, Interferometer Simulations, Multi-ring FROSTI optimization for A# 
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| 4D parameter space visualization and dimensionality reduction for better optimization |
Thu Oct 30 11:45:44 2025, Liu, Update, Interferometer Simulations, Multi-ring FROSTI optimization for A#
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| Multi-ring FROSTI optimization for A#: dimensionality reduction with PCA vs. t-SNE |
Wed May 3 19:03:47 2023, Julian,Pamella and Cao, Physics, VAC, Modify vacuum asssembly and install RGA
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[Pamella, Julian, Cao]
Today we started re-configuring the vacuum chamber components.
Particle count
10:45 am : Starting
the particle count in the clean room.
11:13 am : Finished the particle count in the clean room.
Zone 3 :
0.3 u: 2535
0.5 u: 1413
1.0 u: 789
Zone 4 :
0.3 u: 457
0.5 |
Fri Jan 27 18:44:31 2023, Julian , Update, General, Vacuum Chanmber Cleaning
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I used the IPA wipes to wipe down the inside of the chamber the best I could. I cleaned the main chamber but not any of the connecting joints. When I finished
I did a once over with a fresh wipe and found no residue. |
Wed Jan 18 22:06:05 2023, Julian, Update, ELOG, Cleanroom Update
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| I wiped down all the inner walls of the cleanroom using alcohol wipes, as per Cao's instruction. |
Mon Feb 6 20:02:32 2023, Julian, Update, General, Cleanroom Update
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I wiped down the main table (including frame, legs, and transparent shelf) and workbench using alcohol wipes. Once I cleaned all of the surfaces, I used
the Hepa vacuum to pick up any fallen debris. |
Sat Feb 11 00:17:27 2023, Julian, Update, General, Vacuum Chamber Cleaning   
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Today I finished wiping down the rest of the vacuum chamber, specifically focusing on the connecting ports and outside surface of the chamber. When I was
finished, I test wiped every surface of the chamber and took pictures confirming the current state of cleanliness; Attachment 1 "Wipes for top and bottom
of chamber's upper lip." Attachment 2 " Top and bottom of chamber's lower lip." Attachment 3 "Inside and Outside main chamber." Attachment 4 "Inside connecting |
Thu Feb 23 21:12:33 2023, Julian, Update, General, Vacuum Chamber Cleaning  
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Today I was able to come in and wipe down both sides of the vacuum chamber lid using the regular alcohol wipes and also wipes that were left to dry in the
fume hood then saturated with acetone. I managed to get a good amount of the residue off both the inside and outside surfaces of the lid, then did a test
wipe of both sides using acetone-soaked wipes; pictures of the wipes are attached below. Once I finished with the lid, I used another acetone wipe to test |
Thu Mar 2 20:53:56 2023, Julian, Update, General, Cleanroom Update
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Today Pamella and Julian began the final cleaning of the cleanroom, starting with the HEPA vacuuming and mopping then wiping down every surface of the laser
table. We wiped the main tabletop as well as the legs, but we were unable to completely wipe down the upper frame of the table before we had to leave.
For next steps, Julian will come in on Friday and finish cleaning the frame, then both of us will come in on Monday to finish the final cleaning. |
Sat Mar 4 00:34:46 2023, Julian, Update, General, Cleanroom Update
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Today I was able to finish cleaning the frame of the laser table, and for good measure I wiped down the tabletop and exterior of the vacuum chamber when
I was finished. I was also able to go through and wipe down the bags containing the vacuum parts as well as the tabletop of the workbench. |
Thu Mar 23 18:40:08 2023, Julian, Update, General, Cleanroom Update
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| Today Pamella and I came in to Hepa vacuum and mop the floor of the cleanroom for general maintenance. |
Thu Jul 2 13:27:48 2026, Joshua Marmor, Update, General, HBT SURF Update #1
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| Update on the progress for the HBT measurement. |
Thu Jul 9 12:27:20 2026, Joshua Marmor, Update, General, Week 2 HBT Surf Project
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| Slides for group meeting, updates on HBT measurement |
Wed Jul 15 21:53:32 2026, Joshua, Infrastructure, Cleanroom, Cleanroom cleaning
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[Joshua, Mary, Ma]
On Wednesday (7/15), a particle count measurement was performed in the clean room in all five zones.
Particle Count Measurements: |
Thu Jul 16 10:29:19 2026, Joshua, Update, General, HBT SURF Update #3 
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[Joshua, Mary, Ma, Abhi]
On Wednesday (7/15), the particle count measurement was sufficient, so the FROSTI was transferred into the cleanroom. We unmounted it from
the plastic base, and secured it to the optical table. We also transferred the neccessary parts for the HBT setup and began assembly. The breadboard was |
Thu Jul 16 10:52:02 2026, Joshua, Update, General, HBT SURF Update #3 - group meeting slides
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Tue Jul 21 15:47:55 2026, Joshua, Update, General, HBT SURF Update #4 - Alignment & First Measurement
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HBT Alignment & First Measurement
HBT setup was aligned for maximum power on the transmissive arm, then the beamsplitter
was tilted to equalize the power in each arm. Then, we set the board at
Total power: 0.156 V |
Thu Jul 30 14:15:52 2026, Joshua, Update, General, HBT SURF Update #5 - Group Meeting Slides 
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| Attached are my group meeting slides and some calculations from Mary which predict the photon bunching cross correlation signal. |
Thu Aug 6 14:39:47 2026, Joshua, Update, General, Heating Element Power Data
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This is a measurement done to determine which heating elements output the most power. FROSTI was supplied 33V, and a photodetector was held to the
center of each heating element directly at the aperture.
Element #1 (top), RTD0 - 0.33 V |
Tue May 2 17:03:14 2023, Jon, Cao, Physics, VAC, First pump-down test of vacuum chamber 
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[Jon, Cao]
1. Re-routing of cables
We re-routed the connections between the turbo pump and its fan to the controller. Instead of going through the side of the server rack, they |
Thu Jun 29 18:27:26 2023, Jon, Cao, Infrastructure, VAC, Vacuum bake attempt 3: success! 
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[Jon, Cao]
Summary : We resolved problems with heaters tripping power and were able to proceed with chamber baking
1. Circuit connection adjustment
After yesterday elog 137, today we resolved
most of these issues. After Jon contacted Facilities, the LP3B 6 circuit was reset and the cleanroom filter & light panels resumed to work as normal.
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