 Wed Feb 28 17:49:18 2024, Tyler, Update, TCS, FROSTI Assembly - Days 2-3 
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[Aiden, Jon, Luis, Luke, Michael, Tyler]
FROSTI assembly was completed today. The RTD and power wires were terminated at the DB-25 connectors and
the legs were put on. It is currently placed in front of the stand-in test mass (~5 cm away). The FLIR has also been moved back to it's nominal position.
As of now, it appears there are some shorts within the power cabling. This will be a focus of tomorrow's work.
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 Wed Mar 6 09:57:52 2024, Tyler, Update, TCS, FROSTI Wiring
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Upon finishing the FROSTI assembly last week, we ran into some electrical issues. An electrical short was found between two of the d-sub pins (2 and
8). It appears that the pins were somehow coming into contact with the aluminum surrounding them. This was causing the power supply to trip. The issue
was seemingly fixed by adjusting the positioning of the cabling leading out of the reflector. When handling the device in the future, please make sure |
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Mon Sep 16 14:59:51 2024, Tyler, Update, TCS, FLIR RIN Update 09/16
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Below is the dark noise spectrum of the Red Pitaya, which was measured over the course of a weekend. Additionally, I have successfully measured a signal
from the photodetectors with the FROSTI as the IR source, so it seems there shouldn't be any worry of these particular detectors not being feasible for
the RIN measurement. |
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Wed Oct 2 12:20:43 2024, Tyler, Update, TCS, Updated FROSTI Analysis 10/02/2024
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| Attached below are updates on current FROSTI prototype analysis. |
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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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Tue Jul 18 14:13:46 2023, Sophia , Update, Scripts/Programs, Update on Laser Noise Data Collection and Analysis 6x
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We [Sophia and Tyler] have found a code which will partition our data and generate PSD's and CSD's automatically. We are now in the stage of writing this
into a dynamic code, which so far has been fast-paced because of the framework we have built for it over the past few weeks.
Something to note is that
we have found, especially over long periods of time, the laser goes through periods of extreme noise and the signals often cross from where we set them |
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Thu Jul 27 11:28:36 2023, Sophia , Update, Scripts/Programs, Update on Laser Noise Data Collection and Analysis: Dynamic CSD and PSD Plots
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This week I have successfully been able to implement our dynamic CSD and PSD plotting code, but along the way I encountered a few challenges which I will
outline in this elog post.
Challenges:
1. Once I was able to plot the data through time, I produced a graph of the raw data (shown below in the top
to images) which showed pulsed data instead of a continuous stream. On Tuesday (26th of July) Tyler and I fixed this issue, realizing that calling the |
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Thu Jul 27 14:11:42 2023, Sophia, Update, Scripts/Programs, Update on Laser Noise Data Collection and Analysis: Dynamic CSD and PSD Plots
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Here's a screen recording of the dynamic raw data and PSD/CSD plots as they are now. Will begin working on implementing a code to generate the statistical
estimator for the CSD uncertainty now. (Will talk to Tyler more about whether I can get the lines to happen or not) |
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Mon Jul 31 19:27:30 2023, Sophia, Update, Scripts/Programs, Update on Laser Noise Data Collection and Analysis: Dynamic CSD and PSD Plots
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An update on the CSD/PSD code:
The code is now taking a dynamic average of the points, and that has significantly reduced the noise that we were reading
and the issues I was having with the lines in the plots. The graph for the CSD is still putting up a fight though, and amassing many lines that do not
appear when just scatter plotted. I plan to fix that tomorrow, alongside inserting my own generated signal into the data. I have plotted the coherence |
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Tue Aug 1 15:44:31 2023, Sophia, Update, Scripts/Programs, Update on Laser Noise Data Collection and Analysis: Dynamic CSD and PSD Plots 6x
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We have identified two problems facing the intensity noise calculations, which we are working to solve.
The first of these problems, is that the red
pitaya appears to be taking data approximately 4 times faster than we would expect from the decimation rate based on how quickly it runs. To see if this
was affecting our data, we plugged the red pitaya into a function generator. We found that my code is able to identify the driving frequency, but consistently |
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Mon Aug 7 15:36:18 2023, Sophia, Update, Scripts/Programs, Update on Laser Noise Data Collection and Analysis: Dynamic CSD and PSD Plots 7x
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Today I was able to fix the red pitaya's plotting problem, and get my code to recognize driving frequencies from the function generator to within a 0.5
Hz estimation. The sinusoidal plots I have included are from sending a 1 Hz signal into the red pitaya to see the signal in real time. This allowed me
to see exactly where the system was messing up, and fix from the ground up. Once I had that working, I began to test sending in frequencies in the range |
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Tue Aug 8 16:47:11 2023, Sophia, Update, Scripts/Programs, Update on Dynamic CSD and PSD Plots
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We have fixed our rapid plotting error, and realized that this has not been affecting our data intake! Below is a video of the code progressing, alongside
grabbed images of the raw data. The data is now continuous, and performs as we expect. Next, I plan to add a widget which will dynamically show the peak
values instead of them just being printed in the terminal after each iteration. (Ignore the red box-- it was from me struggling with a now fixed issue). |
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Tue Aug 15 10:35:00 2023, Sophia, Update, Scripts/Programs, Update on Laser Noise Data Collection and Analysis: Dynamic CSD and PSD Plots
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I have successfully added a button to my graphics, but it has posed a strange issue with the CSD and PSD values. When I plot my original code, I still see
the pretty peaks that I was getting originally, while my new code (as shown in the video and in the last screenshot) is giving me more of a line. In my
code that gives the peak values, the CSD values also tend to fluctuate in this new code as well (shown in the first screenshot), before returning to the |
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Tue Aug 15 13:32:37 2023, Sophia, Update, Scripts/Programs, Update on Laser Noise Data Collection and Analysis: Dynamic CSD and PSD Plots
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I have now fixed all issues that I was having this morning, and have added text boxes which show the peak values of both PSD's and the CSD alongside the
graphs. They also update continuously with the graph. This is shown in the top image. The laser was driven at 400Hz, and had 0.5V peak to peak voltage,
both of which appear correctly in the below graphs.
Now that the code is almost fully working (we will finish debugging the screenshot method later |
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Mon Oct 30 11:03:56 2023, Tyler, Update, Scripts/Programs,
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FLIR: After some adjustments, the plot generated from the FLIR measurements look much more symmetric (see attachment). There are more included grid
points, which smooths out the curve as compared to last week.
Red Pitaya: It looks like a new OS update was released for the RP, which includes
a new Python API (was previously only available in C). I'm going to try and update the one we have currently running in lab.
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Tue Feb 6 22:40:25 2024, Michael, Update, Scripts/Programs, Long Crab 1 Design Created In Gtrace
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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. |
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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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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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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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Mon Sep 23 15:11:21 2024, Tyler, Update, Scripts/Programs, Effective Emissivity Analysis and RIN Update
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A quick update on the effective emissivity analysis for the CIT FROSTI testing:
I was able to (roughly) match the OPD data to a referenced COMSOL model, with an applied power of 12.6 W (as seen below). However, when changing
the emissivity of the ETM in COMSOL, the dT profiles do not seem to change much. I am not sure as to why this is the case at the moment, and will continue |
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Tue Jun 27 14:04:42 2023, Sophia A. , Update, Measuring Noise in Interferometer, Interferometer set up and connection to red pitaya
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Today we (Sophia and Tyler) constructed the set-up for the electrical noise calculation that I will be conducting this summer. I have included images of
the setup below. Our system is effectively a green laser, that feeds into a type of polarizer, then into a beam splitter which sends the laser light down
two arms into detectors. We started by connecting the detectors to an oscilloscope to determine whether the signal will exceed 1V, as the red pitaya (our |
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Wed Aug 17 16:04:30 2022, Phoebe Zyla, Summary, Lore, Testing the Cartridge Heater and Collecting FLIR Data
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We have tested the heater to find emissivity, mounted the heater system to the optical table, and have taken irradiance maps of the heater projected
onto the screen.
The heater's emissivity was determined by using a thermocouple in conjunction with the FLIR's temperature calibration. To attach
the thermocouple to the heater initially, I used Kapton tape and ran both the wires of the heater and the thermocouple through the heater bridge. This |
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Tue Nov 21 14:47:24 2023, Tyler, Update, Lore, 1129 Workbench Assembly Update 1
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[Tyler, Shane, Mohak, Cynthia, Luke, Michael, Luis]
Started assembly of the workbench equipment today. We completed the stools, and have constructed the frames of each workbench. All that needs to
be added are the tabletops and the top shelves, which will be done on Monday. |
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Mon Nov 27 14:22:30 2023, Tyler, Update, Lore, 1129 Assembly Update
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[Tyler, Michael, Luke, Cynthia]
The tabletops have been attached to the workbench frames. Unfortunately, one of the tabletops came out of the box
with a large scratch and small dent in the middle. One of the electric top shelves is ready to be attached to the undamaged table, but the other is yet
to be opened. Assembly will be completed Wednesday morning.
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Thu Nov 30 13:50:32 2023, Tyler, Update, Lore, Workbench Assembly Completed
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[Tyler, Luke, Aiden]
The workbenches are now completely assembled and put into their final places. Additionally, the tool chest has been moved.
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Tue Feb 13 01:26:30 2024, Peter, Update, Interferometer Simulations, CARM Power Simulations
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Cao's simulations of the circulating power and gouy phase through a single arm cavity of the interferometer have been reproduced. Images of the plots can
be shown in the pdfs attached. There are approx. 400 lines in this code (scenario_3_carm) that produces these plots. This code also calls on a separate
code source file (thermal_models) that defines many of the functions used in this main simulation. The thermal_models file consists of over 1000 lines. |
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Tue Feb 13 04:05:32 2024, Michael, Update, Interferometer Simulations, Shoelaces 1 Layout Simulated in GTrace
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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. |
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Tue Feb 13 12:26:23 2024, Tyler, Update, Interferometer Simulations, BS Code Update
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I reproduced Cao's CE beamsplitter code (see below for example plots). I received the current info on the beamsplitter parameters for A+ and A# from
GariLynn also. The next steps are to perform a similar power loss analysis on the anticipated A# beamsplitter. |
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Tue Feb 13 13:02:41 2024, Pooyan, Update, Interferometer Simulations, Cacity sacn of Fabry-Perot
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| Created a simple model of Fabry-Perot cavity in SIS, and did a cavity scan. Total power in the cavity, 00 mode, and HOMs is measured. |
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Wed Feb 21 23:15:07 2024, Michael, Update, Interferometer Simulations, Long Shoelaces 1 Layout Created in Gtrace and Fixed Ghosting in Beamsplitter
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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 |
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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. |
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Tue Feb 27 09:06:29 2024, Cynthia , Update, Interferometer Simulations, cavity scan with higher order input laser
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I performed a few cavity scan with the inputing laser with a different mode (not pure 00). For each laser I included a graph for just plotting the order
with highest power (for example 1st order laser input the first plot only scanned for 1st order in that cavity), and I have also included a graph scanning
for order 1-10. |
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Sun Apr 7 13:42:51 2024, Michael, Update, Interferometer Simulations, Update on status of gtrace project
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[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 ( |
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Mon Apr 8 14:43:29 2024, Pooyan, Update, Interferometer Simulations, SIS update single and coupled cavities
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[Pooyan, Cynthia]
Attached is a brief recap PDF file. A video file showing separate HOMs plots for the cavity scan with ETM08 surface map is also
attached.
The codes are available at https://git.ligo.org/uc_riverside/hom-rh/-/tree/main/SIS |
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Mon Apr 8 14:57:41 2024, Cynthia, Pooyan, Update, Interferometer Simulations, performed cavity scans for O4 O5, and coupled cavity
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Mon Apr 15 15:25:10 2024, Cynthia, Update, Interferometer Simulations, progress on simulation so far
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Mon Apr 22 15:06:33 2024, Cynthia , Update, Interferometer Simulations, cavity scan update
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[Cynthia,Pooyan]
Completed some simulations injecting 0-10th order modes. Some graphs will be used for the poster after some further titles, axis, and
range adjustments. |
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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 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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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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Mon Jul 1 15:19:42 2024, Cynthia , Update, Interferometer Simulations, O4 and O5 mirror cavity scans with thermal effect
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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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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 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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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 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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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 15:44:52 2024, Cynthia , Update, Interferometer Simulations, performed cavity scans with thermal effects and ring heater
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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 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. |