 Mon Aug 12 16:35:30 2024, Luke , Update, , Ringheater modeling Update 
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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 |
 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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Tue Aug 6 13:07:07 2024, Xuejun, Update, Interferometer Simulations,
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[Xuejun]
The width and location of the measured in-air change in temperature profile has been determined to be 0.045m and 0.137m respectively. Subsequently,
a fake irradiance profile was able to be generated that best resembled what the actual irradiance profile could be using this information for testing in
COMSOL. The generated irradiance profile that output the most similar change in temperature profile as the measured in-air profile has been included as |
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Sun Aug 4 09:01:01 2024, Michael, Update, Interferometer Simulations, Update on SRC Mode Mismatch Analysis
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| An update on my analysis to minimize mode mismatch/scattering by introducing toroidal mirrors to the SRC. |
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Fri Aug 2 13:50:22 2024, Shane, Update, CDS, Serial Comm. Test (Agilent Turbo Pump)
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Did a brief communication test with the agilent turbo pump today, to see if we could get serial communications up and running for it. Used a simplified
python script with sockets package to establish a connection and send a simple command to query the pump's operational status. The connection was successful,
and had no issues establishing. The command also sent successfully, and received a response. The response didn't make sense, though, as all the possible |
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Thu Jul 11 21:01:37 2024, Jon, Infrastructure, General, Cable tray installed in 1129
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Today I installed a 10' cable tray in 1129, for permanently routing Ethernet lines to the workstations. It is securely bolted to C-channels in the side
wall and in the center cable tray. |
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Tue Jul 30 07:42:47 2024, Jon, Infrastructure, General, Cable tray installed in 1119
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Yesterday I installed another 5' cable tray in 1119, for permanently routing Ethernet lines to the L-bench. It is securely bolted to the top of the electronics
rack, on one end, and to the top of the glass-door storage cabinet, on the other. This eliminates the need for the cable ramp which previously sat behind
the rack. |
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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 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. |
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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. |
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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. |
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Fri Jul 26 17:25:42 2024, Jon, Infrastructure, Computers, New workstation ws4 installed in 1129
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Today I installed the second desktop workstation in 1129. The new machine is an Intel NUC13ANHi5, with a 12-Core Intel i5-1340P CPU, 32GB DDR4 RAM, and
a 1TB SSD.
I loaded it with a fresh installation of Debian 12 and installed the LIGO CDS workstation (control room) tools. It is assigned the hostname ws4 |
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Mon Jul 22 18:19:34 2024, Luke, Update, VAC, Zero length reducer stuck bolts
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Today, I borrowed a bolt extractor drill bit from the machine shop to remove some stuck bolts from the zlr. Before starting, I laid down a sheet of aluminum
foil on the work table and wiped down all the tools I was going to use. I began by drilling a small pilot hole and then enlarged it with a 5/32 drill bit.
However, when I attempted to use the bolt extractor, it didn't grip the bolt effectively. Our bolts were too seized, causing the extractor bit to repeatedly |
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Tue Jul 9 18:19:50 2024, Shane, Update, CDS, ADC-DAC loopback testing and IOLAN installation
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[Shane, Jon]
Finished ADC-DAC loopback testing today (see attached xlsx file or access directly here).
All looks well with the first 8 channels, with the gain hovering just under 2. Also edited c1msc model in simulink to add channels 7-15 (the last 8 channels),
and changed the rate back to 64K. See image 1 for the updated c1msc model. The last 8 channels are also looking good and show no problems, with slightly |
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Tue Jul 16 18:43:07 2024, Shane, Update, CDS, ADC-DAC loopback testing and IOLAN installation
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UPDATE:
Follow up ADC-DAC loopback testing now complete, matching all the ADC channels to a single DAC channel, and then matching all the DAC channels
to a single ADC channel (see attached xlsx file or access directly here).
Also note c1msc model file has been updated to include the second set of 16 ADC channels. The newly added channels also have their own filter modules, |
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Mon Jul 15 15:52:40 2024, Michael, Update, Interferometer Simulations, aLIGO locking with varying SRC mirrors and measuring mode mismatch
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Mon Jul 15 15:44:52 2024, Cynthia , Update, Interferometer Simulations, performed cavity scans with thermal effects and ring heater
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Mon Jul 15 14:49:06 2024, Pooyan, Update, Computers, Synology NAS server setup
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Installed a Synology NAS server (Synology RackStation RS1221) in lab room 1129, with host name “scribe” and ip “192.168.1.17”. It is mounted on the rack
and each of its 8 storage bays has a 2TB SSD disk. It will be used to set up automated backups of all the lab machines (e.g., chimay, logrus, megatron).
One shared storage is set on it with SHR-2 as its RAID type. It can tolerate the failure of two disks and has 10.4TB of total capacity. |
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Mon Jul 15 14:28:32 2024, Pooyan, Update, Interferometer Simulations, aLIGO test mass surface profiles
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Created a Google Slides presentation to summarize all the mirror surface map information that we use for simulating interferometers.
A+ expected maps are based on correspondence with G. Billingsley. The estimate for the A+ ITMs will be to take the “as polished” data and add coating
non-uniformity to it. (T2000398) Neither of these are scaled for the precise thickness of the Ti:Ge coatings. |
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Mon Jul 15 13:30:49 2024, Luke , Update, VAC, Problem with 2.75" to 1.33" zero length reducer
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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 |
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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). |
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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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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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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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Mon Jul 8 17:01:45 2024, Shane, Update, CDS, New CyMAC internal layout
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[Jon, Shane]
Internal layout of CyMAC has been updated (labeled image attached) to accommodate the replacement of the two ribbon cables. Looking down
on the chassis from the front, and going from left to right, the new placement is as follows: BIO card, DAC adapter board, ADC adapter board, DAC card,
ADC card. NOTE: As part of ADC-DAC loopback testing, we're disconnecting from the FROSTI readout chassis and using the cables to connect directly from |
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Mon Jul 8 12:26:10 2024, Michael, Update, Interferometer Simulations, Minimizing Astigmatic Effects in the SRC of LIGO
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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 |
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Mon Jul 8 10:39:14 2024, Xuejun, Update, FLIR, Average Temperature Profile
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After taking data for each of the individual heater elements, I imported them into python and overlayed them to produce an average temperature profile.
I rotated the 7 of the elements to align with element 1's profile and averaged them out. By setting the range to 28C - 33C (this gave the best visibility
of the heating pattern) it gave the profile attached. |
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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 |
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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 |
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Fri Jul 5 13:17:44 2024, Liu, Update, Interferometer Simulations, Four-quadrant FROSTI-like RH for astigmatic thermal actuation for CE optics 7x
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In the CE corner layout design and down selection study, interferometer layouts with large incidence angles on some of the curved optics are being considered,
such as the folding mirrors in the "long crab". This however generates astigmatic beams upon reflection and results in mode mismatches in coupled cavities
that need to be mitigated. Astigmatic thermal actuation for the optics involved is thus essential. One way we are considering is to implement a FROSTI-like |
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Mon Jul 1 15:19:42 2024, Cynthia , Update, Interferometer Simulations, O4 and O5 mirror cavity scans with thermal effect
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Mon Jul 1 11:45:45 2024, Sid, Update, Interferometer Simulations,
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Progress update: Most of last week was spent getting set up with SIS, and learning how to do basic simulations. The goal for this week is to begin reproducing
the methodology from T2000338. I have begun with studying perturbations to mirror curvature and position in a simple FP cavity, but thus far have been
unable to get the same results. |
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Fri Jun 28 18:15:16 2024, Luke, Update, VAC, Vacuum chamber
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We will be configuring the RGA line to remove the spherical cube from the system. Currently our plan for the new design is to connect a 4.5" to 2.75"
Reducing Cross to the gate valve on the vacuum system. It will be orientated vertically with the turbo pump on top coming off the end will be a 90 deg
elbow. On the bottom there will be a 4.5" to 2.75" Zero length reducer attached to that will be a Tee on one side the pressure sensor and the other the |
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Fri Jun 28 10:43:13 2024, Xuejun, Update, Cleanroom, Frosti
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[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.
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Thu Jun 27 13:42:02 2024, Shane, Update, Cleanroom, cleanroom 5 zone particle count measurement
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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. |
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Thu Jun 27 11:09:14 2024, Liu, Update, Scripts/Programs, Straight edge STEP files and ray loss analysis
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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 |
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Wed Jun 26 16:39:34 2024, Luke, Update, VAC, Vacuum chamber leak checking
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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. |
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Thu Jun 20 18:01:11 2024, Jon, Infrastructure, Computers, New workstation ws3 in 1129
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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, |
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Wed Jun 26 15:33:41 2024, Jon, Infrastructure, Computers, New workstation ws3 in 1129
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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 |
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Tue Jun 25 17:19:42 2024, Luke, Update, VAC, Vacuum chamber leak checking
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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 |
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Tue Jun 25 12:34:18 2024, Shane, Update, Cleanroom, cleanroom cleaning and particle count
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[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: 32840.5
u: 12471.0 u:332
zone 4: 0.3 u: 18290.5 u: 5811.0 u: 207
11:15 |
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Mon Jun 24 21:38:25 2024, Pooyan, Infrastructure, Computers, Computer server changes in 1119 and 1129
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[Jon, Pooyan, Tyler]
A few computer machine changes have been made. |
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Mon Jun 24 14:28:51 2024, Cynthia , Update, Interferometer Simulations, SIS cavity with thermal effect
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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. |
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Fri Jun 21 11:47:30 2024, Liu, Update, Scripts/Programs, COMSOL simulation on alternative straightened heater elements design 6x
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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 |
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Wed Jun 19 18:45:14 2024, Luke, Update, , Vacuum chamber reassembly
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[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.
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Mon Jun 17 11:47:46 2024, Liu, Infrastructure, General, Temporary cooling units for the labs
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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. |
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Fri Jun 14 13:32:13 2024, Liu, Update, Scripts/Programs, COMSOL simulation on rectangular heater elements design 6x
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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. |
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Mon Jun 3 14:14:39 2024, Tyler, Update, FLIR, Initial CIT FROSTI Analysis
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[Tyler]
Attached below are the initial results of the CIT FROSTI testing analysis.
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Mon Jun 10 14:52:38 2024, Tyler, Update, FLIR, CIT FROSTI Analysis Update
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[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 |
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Mon Jun 3 14:59:44 2024, Cynthia, Update, Interferometer Simulations, Created cavity scan with LG modes
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Mon Jun 3 09:24:48 2024, Aiden, Update, VAC, Vacuum Chamber Rendering
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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". |
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Fri May 31 19:37:47 2024, Luke, Update, , Vacuum chamber Disassembly
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[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 |
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Thu May 16 15:23:14 2024, Shane, Update, Cleanroom, Cleanroom cleaning and particle count
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[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: 3321.0 u: 41
zone 4: 0.3 u: 81060.5 u: 24941.0 u: 831
2:08 |
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Mon May 13 14:53:29 2024, Peter, Update, VLC Update, VLC
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| VLC Update WEEK 7 attached below |