 Sun Mar 23 15:39:06 2025, Luke Johnson, Update, Scripts/Programs, Ringheater Location optimization 
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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. |
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Mon Sep 16 07:28:16 2024, Luke, Update, Interferometer Simulations, Ring heater update
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Sat Jul 13 15:09:04 2024, Luke, Update, General, Ring heater COMSL model update
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After the feedback from last meeting and Liu's help narrowing down what I should do to improve the model. I made some changes: First with Liu's help
I made the proportions of the test mass and ring heater much more reasonable and parametrized by constants. Second from Cao's paper "FROSTI Nonimaging
Reflector Design" Liu showed me what I should do to define the elliptical mirrors. Third during Friday's modeling/programming meeting walked me through |
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Tue Feb 27 03:26:28 2024, Michael, Update, Interferometer Simulations, Reverse aLIGO Layout Created in Gtrace
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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. |
 Wed Feb 28 12:02:08 2024, Tyler, Update, General, Resistors for Heater Elements Update
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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:
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Wed Jan 17 15:47:49 2024, Aiden, Update, General, Resistors for Heater Elements
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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 |
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Tue Feb 18 11:19:13 2025, Luke , Configuration, VAC, Repositioning of the lid's temperature probe
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Before the recent bake I slightly repositioned the temperature probe on the lid from beside the heater tape to under the heater tape. This was done to better
know and control the temperatures of the chamber while baking. It has appeared to work with the temperatures being held very close to the 120C target.
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Mon Jul 24 14:55:53 2023, Jon, Update, VAC, Removed extension power cable
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I removed the extension cable that was powering the leftmost heater controller, since there is no bake currently happening. It is currently powering the
LED over the electronics bench, and can be removed if needed. I will be ordering more extension cords to permanentize our setups. |
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Tue Oct 29 16:37:35 2024, Tyler, Update, Electronics, Red Pitaya OS Update
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The Red Pitaya ecosystem has been upgraded to OS 2.00-35, with a key feature being greater freedom in adjusting the sampling frequency for signal
analysis. Before, decimation factors could only be applied if they were a power of 2 (i.e 2,4,8,16,...) up to 65536. Now, the factors can be any power
of two up to 16, and any whole number greater than 16 up to 65536. Further information can be found here. |
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Tue Apr 25 11:56:37 2023, Jon, Update, VLC Electronics, Red Pataya has arrived
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| The Red Pataya 125-14 starter kit that we ordered for locking the 532 nm cavity has arrived. I left it laying on the optical table near the laser. |
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Mon May 13 13:03:41 2024, Tyler, Update, FLIR, Readout Code Updates
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[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 |
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Fri Feb 2 16:56:56 2024, Jon, Update, CDS, RTS model implemented for FROSTI RTD readouts
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Summary
Today I finished implementing an RTS model to read out the integrated FROSTI RTDs (temperature sensors) via the CyMAC. The model is
named "MSC" and is located at cymac:/opt/rtcds/usercode/models/c1msc.mdl. We successfully tested it with the heater elements operating in vacuum at low
power (12 VDC), finding them to reach an average steady-state temperature of 160 C. |
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Tue Jan 16 12:20:21 2024, Tyler, Configuration, Electronics, RTD Readout Chassis Update 2
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I performed another continuity test on the RTD chassis wiring, and everything seems to be set up correctly. The chassis should be ready for installation.
Quote:
Below is the current state of the |
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Tue Jan 9 12:08:59 2024, Tyler, Configuration, Electronics, RTD Readout Chassis Update
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Below is the current state of the RTD readout chassis wiring. Initial continuity tests seem good, will run through one more time to confirm.
Quote:
The custom front and rear panels for |
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Thu May 2 22:43:36 2024, Tyler, Update, Electronics, RTD Readout Chassis Redesign
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[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 |
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Fri Dec 29 16:02:27 2023, Jon, Configuration, Electronics, RTD Readout Chassis
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The custom front and rear panels for the RTD readout chassis arrived last Friday. I installed them in the chassis frame to check their fit. They fit
very well, so all that now remains is to complete the internal wiring and test the connections.
The chassis panel designs are archived to LIGO-D2300452 and LIGO-D2300453. |
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Thu Mar 21 16:56:42 2024, Tyler, Update, DAQ, RTD Parameter Calibration
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[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: |
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Mon Mar 25 10:55:33 2024, Tyler, Update, DAQ, RTD Parameter Calibration
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Refitted RTD calibration, neglecting quadratic term:
R_0 (ohm) Alpha (1/C)
RTD 0 79.3962 0.002031
RTD 1 78.2874 0.002530 |
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Tue Mar 26 13:51:56 2024, Tyler, Update, DAQ, RTD Parameter Calibration
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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 |
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Mon Jul 29 13:39:16 2024, Tyler, Update, DAQ, RTD Parameter Calibration
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[Tyler]
Using the data taken during the FROSTI testing at Caltech, I attempted to find a better calibration of the RTD sensors, given our past issues
with inaccurate readings. The fit parameters, alpha and beta, are still all different from the initial values given to us by Fralock (alpha = .003, beta
= 1.003e-6, R_0 was not given), but the true values will differ based on factors such as part geometry.
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Mon Nov 20 10:10:50 2023, Tyler, Configuration, Electronics, RTD Logic/Schematic Diagrams
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Below are a basic diagram of what the RTD measurement circuit logically looks like and an example schematic of the actual wiring. The schematic wiring
will be placed internally into a chassis, connected to the RTDs via DB25 cable.
Note: The DB25 Breakout Board connector is Female, not Male. |
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Tue Jan 23 12:17:41 2024, Tyler, Update, Electronics, RTD Chassis
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After updating the wiring in the RTD Chassis, a signal is now seen at each ADC input. However, there seems to be a discrepancy between the voltages
I measured out with the multimeter (see below). Next steps include:
Finish final debugging
Calibrate ADC inputs with known voltage source (likely to use DAC).
Voltage Readings:
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Tue Jan 30 11:36:19 2024, Tyler, Update, Electronics, RTD Chassis
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Quote:
After updating the wiring in the
RTD Chassis, a signal is now seen at each ADC input. However, there seems to be a discrepancy between the voltages I measured out with the multimeter (see |
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Mon Nov 13 11:07:50 2023, Tyler, Update, VAC, RTD Analysis
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After initial analysis from last week on a single RTD, I then extended to looking at all 8 in series with R_ref (set to 1 kOhm). Shown below are the
edge cases for the setup:
RTDs are all at ambient lab temperature. This would correspond to a minimum resistance value.
RTDs all read out 400 C. This gives the maximum resistance value.
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Tue Jan 14 10:27:14 2025, Tyler, Update, TCS, RIN Updates
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[Tyler]
Attached below are updated plots for the FROSTI RIN measurements for Jan 14 group meeting.
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Wed Dec 11 13:39:30 2024, Tyler, Update, Electronics, RIN Update 12/11/2024
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[Tyler]
Attached below are updated ASD plots for the FROSTI RIN measurements. The parameters set for this are the following:
DFT Size (N): 16384
Sampling Frequency (F_s): 7.629 kHz
Resolution (F_s/N): 0.47
CH0 DC Voltage w/FROSTI
ON: 113.6 mV
CH0 DC Voltage w/FROSTI OFF: -5.7 mV
CH1 DC Voltage w/FROSTI ON: 113.0 mV
CH1 DC Voltage w/FROSTI OFF: |
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Wed Oct 9 13:52:31 2024, Tyler, Update, TCS, RIN Update 10/09/2024
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I tried adjusting the gain settings on the photodetectors to check if this would help improve the RIN spectra measurements. Overall, it doesn't look
like it does, and if anything, looks worse. I assume this is so because as the gain is lowered, the amount of detectable signal from the FROSTI becomes
smaller and smaller. |
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Wed Nov 13 14:03:32 2024, Tyler, Update, Electronics, RIN Update
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[Tyler]
We've added two low-pass filters in hopes of reducing any potential aliasing that may be introducing additional noise into the power spectra
for the RIN measurements. It still looks like the noise levels are too high. Attached below are some recent measurements taken with the FROSTI powered
on and off.
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Wed Nov 20 12:59:37 2024, Tyler, Update, Electronics, RIN Update
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I went ahead and compared the noise spectrum of the ADC to those of the photodetectors with the FROSTI on and off. As discussed last meeting, it looks like
the measurements with the Red Pitaya (RP) are limited by the ADC noise floor. Another avenue to explore in this measurement could be switching to the
cymac ADCs. |
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Wed Nov 27 13:48:01 2024, Tyler, Update, Electronics, RIN Update
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[Tyler]
I downgraded the Red Pitaya back to OS 2.00-18 due to runtime errors during measurement. Once I did this, the device appeared to work much
better than it has the last few weeks. First, it appears we can actually see the cutoff of the added low-pass filters that were added in to the RIN setup.
Second, there does appear to be a difference again between the FROSTI ON state versus the dark state (i.e. FROSTI OFF). A long measurement of the ADC noise |
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Tue Mar 4 10:28:58 2025, Tyler, Update, TCS, RIN Plot Updates
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Mon Aug 12 16:24:34 2024, Tyler, Update, Cleanroom, RIN Measurement Update 1
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[Tyler]
For some preliminary tests, I moved the IR photodetectors outside of the cleanroom and onto the other optical table. The basic goal was
to obtain a signal from both photodetectors. To achieve this, one of the heater cartridges used for early FLIR measurements months ago was hooked up to
a power supply (PS). The PS was set to supply 0.20 A with a voltage of 2.8 V; the corresponding power is thus 0.56 W. With this, I was able to measure |
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Mon Jul 29 14:30:16 2024, Tyler, Update, Cleanroom, RIN Measurement Set-up
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[Tyler]
I have begun moving parts into the cleanroom for the upcoming FROSTI RIN tests that will be conducted within the next few weeks. While waiting
for the rest of the equipment to arrive to perform the full-scale tests, I have additionally moved the FROSTI under the shelf above the optical table,
where it will stay for the meantime. As always, please use caution when in the cleanroom. Aside from the FROSTI, the IR photodetectors that will be used |
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Thu Jul 11 15:53:39 2024, Luke, Update, VAC, RGA line upgrade
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[ Luke, Jon ]
Started work at 11:00
As mentioned in my previous post the RGA was not clearing the table because of a tilt in the cross. So I removed the 90 deg elbow, loosened the |
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Fri Aug 23 16:08:32 2024, Luke, Update, VAC, RGA line leak testing
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[Luke, Luis, Jon, Tyler]
On the 22nd Dr. Richardson showed Luis, Tyler and I how to preform a leak test with the RGA. We did the initiall test and found a few leaks two
were particuarly bad highlighted in orenge below. To try and remidy this we planned on replacing the copper gaskests on the leaking flanges. We then began |
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Tue Aug 27 15:01:26 2024, Luke, Update, VAC, RGA line leak testing
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[Luke, Tyler]
On the 27th Tyler and I ran the RGA leak test again with the electron multiplier on. These were the leaks we measured. The chamber's overall pressure
was at ~6e-8 torr. |
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Wed Jul 10 17:31:07 2024, Luke, Update, VAC, RGA line disassembly and upgrade
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[ Luke, Cynthia, Michael, Xuesi, Anthony ]
Started work around 12:45
We vented the chamber first and once it reached atmospheric pressure we started taking apart the RGA line. |
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Fri Nov 10 08:32:34 2023, Jon, Update, VAC, RGA experiments
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I ran a 3-minute degas cycle of the RGA filament for the first time yesterday (in this process, the filament gets very hot in
order to "boil off" settled particulate). I was surprised to see the pressure (of not just the RGA volume, but also
the main volume) rise from 2e-8 to 5e-6 torr.
This observation, |
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Tue Nov 14 17:21:40 2023, Jon, Update, VAC, RGA best practices
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As a follow up ELOG 261, I have received advice from one of the vacuum experts at LIGO Hanford
on best practices for our RGA:
For future RGA degassing, definitely keep the main volume isolated, since it |
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Wed Dec 11 16:06:05 2024, Luis, Update, VAC, RGA Status
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[Luis]
I rebooted Spica and I was able to connect the RGA again. After Connecting the RGA, I left the filament on. |
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Wed May 10 10:49:34 2023, Aiden, Update, General, RGA Software
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[Aiden, Cao]
Went over how to use the RGA software, how to change the graph units, scaling and mass detection. Also went over how to remove the RGA from
the vacuum system as well as procedure for turning it on. |
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Mon Sep 16 13:51:23 2024, Luis Martin, Update, VAC, RGA Scans
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[Luis, Luke}
Three RGA scans were taken. The improvement in the amount of HC in the vacuum is visible across the different measurements.
Images are attached. |
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Wed Sep 25 09:06:09 2024, Luis Martin, Update, VAC, RGA Scans
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RGA
Scan Comparison
The following images compare the RGA scans from 9/23/24, after the first bake with the new vacuum system,
with those from 3/14/24, after bake 12 with the old system. |
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Thu Dec 12 13:06:39 2024, Luis, Update, VAC, RGA Scan and vacuum system updates
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[Luis, Luke]
RGA Volume: T = 21°C, P = 1.74e-9 Torr
Main Volume: T = 22°C, P = 5.60e-9 Torr
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Thu Dec 5 10:31:13 2024, Luis , Update, VAC, RGA Scan and RGA updates
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[Luis,Shane]
An RGA scan was taken on Dec 4th. The results are attached at the end of the e-log. As we can see, the scan results are under
the allowed limits. After the scan, Shane and I worked on the vacuum connections. The filament was turned off, and the RGA was disconnected from Spica. |
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Wed Oct 16 13:58:59 2024, Luis Martin, Update, VAC, RGA Scan
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The following figure displays data acquired on 10/09, and it shows that we are no longer below the cleanliness standard. Also, the system's pressure
went up to 1.9x10-8 Torr (approximately 7x10-9 Torr previously). This might be due to a leak somewhere in the system. More tests
will be performed later. |
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Wed Oct 23 12:08:36 2024, Luis Martin, Update, VAC, RGA Scan
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[Luke, Luis, Mary, Ma]
On 10/22/24 Luke, Ma, Mary and myself ran a RGA scan, the results are displayed below. The overall pressure of the vacuum was 2.0e-8 and the temperature
readings were 26C for the RGA and 25C for the main volume. |
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Thu Feb 20 17:07:36 2025, Luis, Update, VAC, RGA Scan
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[Ma, Luis]
February 20, 2025 - 3:30 PM
Ma performed an RGA scan with the vacuum system containing the heater elements. The results are attached below. |
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Mon Feb 24 17:50:13 2025, Luis, Update, VAC, RGA Scan
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[Ma, Luis]
February 24, 2025 - 1:00PM
Ma performed an RGA scan with the vacuum system containing the heater elements. The results are attached below. |
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Wed Nov 6 13:48:55 2024, Liu, Update, Interferometer Simulations, QN modeling update
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| Slides |