 Mon Nov 20 20:37:45 2023, Aiden, Update, VAC, Clean and Bake Batch 20
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[Aiden, Luis]
Started to clean and bake the macor parts for the FROSTI reflector. Per LIGO documentation cleaned the macor in liquinox for 10 minutes and
put them in the oven at 200 degC for 24 hours. |
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Mon Oct 9 21:41:24 2023, Aiden, Update, Clean & Bake, Clean and Bake Batch 19
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| Bagged and tagged the parts from batch 18. Started the Copper batch that includes all the gaskets needed to start the vacuum chamber upgrade. |
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Sat Oct 7 17:10:27 2023, Aiden, Update, Clean & Bake, Clean and Bake Batch 18
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Bagged and tagged the parts from Batch 17 and placed them in the clean room on the optic table. Also started an aluminum batch of parts that included the
kf clamps and the heater mounting parts. |
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Tue Oct 3 15:07:48 2023, Aiden, Update, Clean & Bake, Clean and Bake Batch 17
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| Cleaned and baked all the stainless steel parts in Batch 17. Check data base for more details on this. |
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Thu Sep 28 15:17:13 2023, Aiden, Update, Clean & Bake, Clean and Bake Batch 16
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| Bagged and Tagged the parts from batch 15 and started baking batch 16 which includes the 6" to 8" reducer. |
Tue Sep 12 15:31:31 2023, Aiden, Update, Clean & Bake, Clean and Bake Batch 15 
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Cleaned and Baked the SS screws for the heater mount. Check the Clean and Bake data base on the website to get a precise list of the parts and their numbers.
Cleaned them with liquinox in the ultra sonic washer for 10 minutes. Then dried them with nitrogen. Then put the stainless steel parts into the oven for
the following steps; 1. Ramp to 100 C in 15 minutes 2. Dwell at 100 C for 30 minutes 3. Ramp to 200 C in 30 minutes 4. Dwell at 200 C for 48 hours 5. Turn |
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Fri Jun 16 17:40:28 2023, Aiden, Update, Clean & Bake, Clean and Bake Batch 14
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Cleaned and Baked the new and 2.75" copper gaskets for the vacuum system. Cleaned them with liquinox in the ultra sonic washer for 10 minutes. Then dried
them with nitrogen. Then put the copper parts into the oven for the following steps; 1. Ramp to 100 degC in 15 minutes 2. Dwell at 100 degC for 30 minutes
3. Ramp to 175 degC in 30 minutes 4. Dwell at 175 degC for 24 hours 5. Turn off
Also bagged and tagged the parts from Batch 13 and placed them into |
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Tue Jun 13 13:25:05 2023, Aiden, Summary, Clean & Bake, Clean and Bake Batch 13
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Cleaned and Baked the new 1.33" and 2.75" blanks for the vacuum system. Cleaned them with liquinox in the ultra sonic washer for 10 minutes. Then dried
them with nitrogen. Then put the two stainless steel parts into the oven for the following steps;
1. Ramp to 100 degC in 15 minutes
2. Dwell at 100 degC
for 30 minutes
3. Ramp to 200 degC in 30 minutes
4. Dwell at 200 degC for 48 hours
5. Turn off |
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Mon Apr 24 17:38:45 2023, Aiden, Summary, General, Clean and Bake Batch 12
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Today I Bagged and tagged the o-rings from batch 11 and placed them inside the clean room. I also cleaned batch 12 parts in liquinox for 10 minutes and
them placed them into the oven where they will undergo the following steps;
1. Ramp to 100 degC in 15 min.
2. Dwell at 100 degC for 30 min.
3. Ramp
to 200 deg C in 30 min.
4. Dwell at 200 deg C for 48 hours.
5. Off |
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Tue Feb 7 17:27:30 2023, Aiden, Physics, ELOG, Clean and Bake Batch #1
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Cleaned SS parts with liquinox for 20 min. Then put in oven for 5 steps;
1. Ramp, 100 degC, 15 min
2. Const, 100 degC, 30 min
3. Ramp, 200 degC, 30 min
4.
Const, 200 degC, 48 hours
5. Ramp, 25 degC, (off)
PS. Ultrasonic washer does not have heating feature. |
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Wed Mar 27 00:03:57 2024, Pooyan, Update, Computers, Chimay relocation to Physics 1129
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[Jon, Pooyan]
Moved Chimay from the server rack in Physics 1119 to a new rack in Physics 1129. It is connected to the switch in that rack
and has the same ip address as before.
All services are up and running.
It appears that JupyterHub creates some processes whenever a user
connects to an instance of it, but in some cases does not stop those processes after the user is not using that instance. This results in having lots of |
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Mon Sep 9 14:27:36 2024, Pooyan, Infrastructure, Computers, Chimay backup attempt
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One ongoing work is to make all lab machines automatically backed-up on Scribe on a daily basis. The updates should be boatable and stored for some time
(potentially a few weeks) on Scribe. Making whole disk images has already been tried for some of the machines with no problems. (e.g., Cymac and WorkStations)
The same thing can not be done with Chimay though, as it currently has one huge RAID-controlled volume that stores all the information (OS, home |
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Mon Jul 24 16:19:29 2023, Shane, Jon, Update, Electronics, Chassis semi-assembled and moved
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Began assembly on AA and AI chassis today, moved them both to top work bench shelf (image attached). They are delicate so please do not disturb them or
put anything on top of them. |
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Tue May 9 20:55:12 2023, Jon, Infrastructure, VAC, Calibrated Ar leak rate
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For future reference, the calibrated Argon source has a leak rate of 7.55E-8 atm cc/s, or equivalently 5.74E-8
torr L/s. This can be used to calibrate RGA scans to units of physical leakage (outgassing) rate. |
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Sun Mar 24 11:50:37 2024, Aiden, Update, Clean & Bake, Cal Tech FROSTI Parts
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| Bagged the FROSTI legs and feet after the conclusion of the clean and bake. They are double bagged and sitting in the flow bench. |
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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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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. |
 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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Mon Mar 6 15:32:58 2023, Jon, Infrastructure, General, Cabinet installation completed
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Jon, Cao, Peter
This morning Facilities delivered and installed two new cabinets with sliding glass doors.
The smaller of the two (36" W x 13" D x 84" H) has been installed in the Clean & Bake area adjacent the flow bench. The larger one (48" x 16" |
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Mon Jan 15 22:29:34 2024, Jon, Infrastructure, General, Cabinet installation & lab clean-up completed
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[Jon, Tyler, Aiden, Shane, Pooyan, Michael, Cynthia, Luke]
On Wednesday, we completed long list of work towards making the new lab (1129) fully operational and enabling the next phase of FROSTI testing.
Cabinet Installation
Three new VWR cabinets with sliding glass doors were installed in 1129. Each unit measures 48" |
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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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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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Tue Jun 3 11:54:06 2025, Cece Ochoa, Update, , CE Cavity Design Update
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| Update on the design for the CE Cavity Mirrors |
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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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Tue Jun 3 11:50:08 2025, Pooyan, Update, CDS, CDS update
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There are three major issues with the lab's CDS system that should be addressed. They are ordered from the highest priority to the lowest.
CyMAC has stopped serving the fast channels (65k Hz)The channels are still there, and the data from the slow (16 Hz) channels is served correctly, but the fast data is not served. As a result, diagggui |
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Tue Jun 10 12:11:14 2025, Pooyan, Update, CDS, CDS update
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The MEDM models issue was fixed. The issue was that building the c1msc model alone was not enough and we had to re-build the c1iop as well, although
no changes has been made to the c1iop. Added a note in the wiki on this for future reference.
For
writing the fast channels to the frame files, our CDS system should have a GDS broadcaster. I followed this |
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Wed Jun 11 16:19:37 2025, Pooyan, Update, CDS, CDS update
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Fast channels recorded to .gwf frame files
Had to add a DAQ Channels block to the c1msc model for those channel to be recorded in the
.gwf frame files. The block is in the CDS_PARTS, and I just had to copy it to our model. Here is the example text for the channels: |
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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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Wed Aug 9 17:35:26 2023, Shane, Update, CDS, Binary output chassis finished
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Finished the internal wiring for the binary output chassis today, which completes its assembly. Also secured ribbon cables and chassis lid with their respective
screws. Note: one of the spade lugs' internal metal piece is a little loose and had to be reinserted after falling out once. Seemed secure after this,
and I checked continuity on everything and it was all good. |
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Wed Aug 16 17:17:02 2023, Shane, Jon, Update, CDS, Binary input chassis powering correctly
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Binary input chassis passed power-on test, and is lighting up as expected. Binary output chassis also successfully powered on. AA and AI chassis not powering
on correctly, need to do some debugging to find the problem. |
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Tue Aug 8 17:03:22 2023, Shane, Jon, Update, CDS, Binary input chassis finished
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Finished assembly of the binary input chassis today, including DC on/off switch and LED installation. external cable assemblies still needed, but internal
work done. |
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Mon Mar 10 21:32:29 2025, Nathan, Physics, Electronics, Beam Profiling and PBS Measurements
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Beam wasn't diverging, however maybe was about to diverge when measurements stopped? Will discuss the PBS measurements and how the voltage changed due to
the wave plate. |
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Thu Apr 27 09:48:34 2023, Aiden, Summary, General, Batch 12 Bagging
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I took batch 12 out of the oven and put them in a bag and placed the bag inside the clean room in the first large stainless steel container.
I also looked
at the small gauge that we felt like needed to be baked and I can confirm that without further cleaning around the inside of the gauge it should not be
connected to the main vacuum. I have attached a photo of the inside of the gauge. |
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Tue Feb 11 08:07:02 2025, Luis, Update, VAC, Bake stopped
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[Luis, Ma]
Feb/10/25 4:00pm
Bake was stopped. |
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Fri Feb 16 18:37:28 2024, Jon, Update, VAC, Bake ended 6:23 pm
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I ended the bake of the UHV system (that began on Monday) at 6:23 pm today by switching OFF both PID controllers. The heaters elements were run at max
power (24 V DC / 200 mA per element) during this bake, and I left them powered at the same level.
At the time, the instrument readings were as follows: |
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Fri Feb 10 15:15:30 2023, Aiden, Update, General, Bagging First Batch
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Aiden Bagged and Tagged the first batch of stainless steel parts shown on the google spread sheet.
1. Removed two parts from the oven.
2. Place them
in the ESD bag.
3. Seal bag with Kapton Tape.
4. Create label including part name and number underneath it.
5. Put label onto the side of the bag where
it is not sealed with tape.
6. Placed bagged items into clean room on work table.
ps. total bags in first batch = 4 |
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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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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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Thu Aug 3 18:03:42 2023, Shane, Jon, Update, CDS, Anti-Aliasing chassis complete
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We finished installing the internal power supply cables in the anti-aliasing chassis today, which concludes its assembly. Work on AI, BI, BO chassis still
underway. |
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Thu Jul 13 15:31:21 2023, Jon, Update, General, Ant traps placed around lab
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In response to reports that ants have been observed in the lab, I placed five ant bait traps around the room today. Each is sitting on the floor on top
of a piece of aluminum foil, in areas unlikely to be inadvertently stepped on. They contain liquid which will spill
out if picked up, so please take care not to disturb them. |
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Thu Jul 13 16:59:03 2023, Jon, Update, General, Ant traps placed around lab
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Update: After seeing the strong response to the first set, I redistributed them to the hottest spots and added one more trap.
Quote:
In response to reports that ants have been observed in the lab, |
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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 |
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Tue Apr 4 16:43:53 2023, Jon, Update, VLC Electronics, Additional Thorlabs PDA10A2
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I ordered a second PDA10A2 and mounting post + spacer (which puts the aperture at the VLC's standard 3" beam height). These arrived today and I delivered
them to the lab. They are sitting on the VLC table near the laser. |
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Wed Dec 14 18:34:33 2022, Jon, Configuration, Electronics, Adapter for 532 nm laser power supply
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I installed an EU-to-US plug adapter for the 532nm laser's 9V power supply. I then re-measured the laser's power with the correct supply voltage (previously
we had been using a 6V supply). At 9V, the max power is 0.83 W, so the laser is confirmed to be Class 2 as labeled. |
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Mon Jul 3 16:26:21 2023, Cao, Infrastructure, DAQ, Access and control Red Pitaya remotely and run it on local machine
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[Cao]
To access and control the Red Pitaya using Python locally on a machine within the local network, one should follow these steps:
Start the SCPI server. This is achieved by first log onto the Red Piatay page
rp-xxxxxx.local/
Go to Development >> SCPI server and turn the server on. (Note : The server is currently running)
|
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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 Dec 4 21:27:53 2023, Shane, Update, CDS, ADC-DAC loopback test results
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Here are the test results from today's ADC-DAC loopback tests. Channels 14 and 15 were the only ones behaving abnormally. Not sure what the issue is, but
needs further debugging. The DAC output was as expected for both of them, but the corresponding ADC inputs were the same regardless of what offset was
used (hovering around values of -4 and -5). NOTE: all measurements listed in the attached table are 'averages' in the sense that the ADC inputs and DAC |
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Thu Jul 27 14:46:55 2023, Shane, Jon, Update, Electronics, AA chassis DC on/off switch assembled
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| Made the first DC on/off switch assembly today and installed in anti-aliasing chassis. Second switch assembly to be completed later. |