ligo-ex ligo-ds
  Richardson Lab Experimental Log, Page 14 of 14  Not logged in ELOG logo
Entry  Mon Apr 7 13:28:49 2025, Xuesi Ma, Update, ,  20250403_151946.jpgELOG_Spike_adapter_filter_on.png20250404_143624.jpgELOG_Spike_adapter_isolate.png20250407_105846.jpg

Test 1: Adapter Board Connected to Filter Board

  • Setup: AI Chassis is powered on. Signal is measured directly from the adapter board. All other ports on the adapter board are connected to the filter board.
  • Observation: Two distinct spikes observed at the beginning of the measurement.

Test 2: Adapter Board Disconnected from Filter Board

  • Setup: AI Chassis remains powered on. Signal is again measured directly from the adapter board. This time, the remaining ports on the adapter board are not connected to the filter board.
  • Observation: Multiple spikes observed, distributed evenly across the entire measurement.

Test 3: Isolation Test with Spare Adapter Board (ongoing)

  • Setup: Suspecting the original adapter board may be faulty, a spare adapter board is used for comparison. Signal is measured directly from this spare board.

Update, 04/08/25, Tue 17:30

Took the old adapter board out of the AI chassis and and used it to connect DAC to AA chassis. If no spikes are seen, it means that the glitches are not originating from this board.

Also checked al the previous spikes using the raw data (65536 Hz sample rate). The duration of the glitches are ~1 second, despite the previous guess that they are happening in the Milli-second scale.

Entry  Tue Apr 15 11:13:43 2025, Xuesi Ma, Update, ,  20250414_120428.jpg20250414_120423.jpg20250411_163105.jpg

Test 4: AI Chassis ground isolation

  • Setup: AI Chassis isolated from the ground with readout directly connected to adapter board
  • Observation: No spike observed.

Test 5: Ribbon cable check

  • Setup: AI Chassis remains isolated from the ground. The signal is measured after the ribbon cable. (Attachment 3)
  • Observation: No spike observed.

Test 6: Single ground connection check

  • Setup: AI chassis powered on but remains isolated from the frame. The signal is measured from the output of the AI Chassis. (Attachment 1 ,2)
  • Observation: No spike observed.
Entry  Tue Apr 22 12:08:46 2025, Xuesi Ma, Update, ,  20250415_161755.jpg20250416_174640.jpg20250422_105614.jpg

Test 7: Reconnect ribbon cables

  • Setup: Reconnect all the ribbon cables, and turned on the AI Chassis while isolated rack
  • Observation: No spike observed.

Test 8: Reconnect to rack

  • Setup: Reconnect the AI Chassis to the rack.
  • Observation: No spike observed.

Test 9: Restore to original position.

  • Setup: CLose up the AI Chassis, and put it back to its original location.
  • Observation: No spike observed.
Entry  Tue May 6 13:19:31 2025, Xuesi Ma, Update, ,  resistance_vs_time_RV_rise_time_24.pdfresistance_vs_time_all_channels_all_time_RV.pdf
 
Entry  Tue May 13 12:35:01 2025, Xuesi Ma, Update, ,  resistance_vs_voltage_all.pdfresistance_vs_voltage_overlay.pdfresistance_vs_time_all_channels_all_time_RV.pdf
 
Entry  Mon May 19 10:59:14 2025, Xuesi Ma, Infrastructure, ,  

Status Update

Previous Status:

All Sorensen power supplies were turned off. The Cymac system was down (all chassis were offline).

If you need more information or assistance in turning them back on, please contact Xuesi Ma.


Update: The systems are now back online.

Note: The Sorensen power supplies’ voltage can now be controlled via channel VEXC8 of the DAC.

If scripting is required, the ezca Python package is highly recommended for interfacing and control.

Entry  Tue May 27 12:52:22 2025, Xuesi Ma, Update, ,  6x

Using the configuration in section 2.11.1 in the Sorensen installation and operation manual (attached below), I'm able to remote control the Sorensen power supply.

I use DAC VEXC8 as the external voltage source and a breakout board to match the configuration of connector J3.

I have recorded 7 cycles (attached below), and am now working on analyzing the data.

Entry  Tue Jun 3 11:54:06 2025, Cece Ochoa, Update, , CE Cavity Design Update CE_Arm_Cavity_.pdf
Update on the design for the CE Cavity Mirrors
Entry  Tue Jun 3 13:08:47 2025, Xuesi Ma, Update, ,  934.jpg933.jpg

We currently have the parts for a DB9 connector but need parts for a DB25 connector, where did we get the parts for the DB9 connector? We may be able to use the same company for the DB25 connector.

Also need a cable for the connectors. Find a DB9 to DB9 cable in 1129, not sure if I can disassemble it and use just the cable.

The pressure in the vacuum chamber rises to 2.12e-8 torr, which needs baking.

Entry  Tue Jun 3 13:16:53 2025, Xuesi Ma, Infrastructure, ,  928.jpg929.jpg931.jpg930.jpg932.jpg

Date and Time: Around 3:50 PM on June 2, 2025

Location and Temperature:

  • Back of the room 1119, around the working station: 86 °F
  • Front of the room 1119, around the doorway: 84.1 °F
  • Back of the room 1129, around the working station: 78.6 °F
  • Front of the room 1129, around the doorway: 78.3 °F
  • In the hallway in front of room 1119: 75.2 °F
Entry  Tue Jun 10 12:13:00 2025, Xuesi Ma, Update, ,  resistance_vs_voltage.pdfresistance_vs_voltage_element_5.pdfresistance_vs_time_all_channels_all_time_RV.pdf

By measuring the resistance of the ladder, I obtained a graph of resistance as a function of voltage.
All the heater elements behave consistently, showing only a small standard deviation.
However, heater element 5 shows a significantly larger standard deviation.
Upon examining the initial ladder graph, I noticed that the resistance of heater element 5 increases following a power outage that resets the system.
At this point, I am unsure why this behavior occurs.

Entry  Tue Jun 17 12:22:43 2025, Xuesi Ma, Update, ,  12x
CYMAC Remote Control Cable Documentation

CYMAC Remote Control Cable Assembly

Cable Functions

The custom cable assembly serves two primary functions:

1. Jumper Connections (DB25 Side - Connector J3)

The following pins are jumpered on the DB25 connector:

From Pin To Pin
Pin 3 Pin 16
Pin 10 Pin 11
Pin 12 Pin 24
Pin 13 Pin 25
Pin 22 Pin 23

2. Signal Wiring (DB9 to DB25)

The following connections are made between the DB9 and DB25 connectors:

DB9 Pin DB25 Pin Function
Pin 1 Pin 9 Positive side
Pin 6 Pin 12 Negative side
Pin 5 Pin 6 Ground

Note: All connections are verified with a multimeter.

Note: This cable allows remote control of the Sorensen power supply with an external voltage source (Cymac DAC).

Note: For more details, check section 2.11.1 from the attached Sorensen power supply manual.

Entry  Tue Jun 24 11:50:15 2025, Xuesi Ma, Update, ,  resistance_vs_time_all_channels_channel_switch.jpgresistance_vs_time_all_channels_channel_switch_one_cycle_before.jpgresistance_vs_time_all_channels_channel_switch_one_cycle_after.jpgresistance_vs_voltage.jpg
Heater Element Resistance Test Results

Heater Element Resistance Test Report

Test Overview

Conducted several on-and-off tests on heater elements at 24V, followed by switching heater elements 5 and 8 by changing their connection pins to the ADC.

Resistance Measurements (Ω)

Heater Element Before Switch After Switch Ladder Test Difference (After-Before)
Element 1 153.09577918 153.11447008 153.83373894 +0.0186909
Element 2 149.70967557 149.8175605 150.08915205 +0.10788493
Element 3 157.88314236 157.87136021 157.39696467 -0.01178215
Element 4 146.80153622 146.78826747 147.77923177 -0.01326875
Element 5 151.80888657 152.2204132 150.44919044 +0.41152663
Element 6 148.24375881 148.32846152 146.89161192 +0.08470271
Element 7 144.72286546 144.76879963 145.03627875 +0.04593417
Element 8 151.4564267 149.14240417 149.88675562 -2.31402253

Supporting Graphs

Attached below are the resistance-time graphs for all heater elements:

  • Complete test duration graph
  • Pre-switch period graph
  • Post-switch period graph
  • Resistance voltage graph after removing data from after power outage

Analysis & Conclusion

The switch did not physically change the resistance of the heater elements, suggesting the measurements reflect their true resistances.

Entry  Tue Jul 1 13:41:36 2025, Xuesi Ma, Update, ,  
[Ma, Liu]

Slides

Entry  Mon Jul 14 23:50:22 2025, Tyler, Update, , Cymac ADC update cymac_ADC_PSDs.pdfch35_ADC_comps.pdf

I've been looking into the performances of individual channels on the Cymac by computing their individual PSDs and corresponding CSDs that show their noise relation to each other. It appears some channels do have lower noise floors than others, and some combinations of these actually do perform similar to the Red Pitaya (showing below the CSD between CHs 3 and 5), although it doesn't look like it's much of an improvement. The best method as of now still appears to be phase-locking two separate ADCs to reduce the correlated noise floor further.

This can be further discussed at the July 22, 2025 group meeting.

Entry  Tue Jul 15 11:47:53 2025, Xuesi Ma, Infrastructure, ,  20250701_165118.jpg20250701_165200.jpg20250701_165329.jpg20250701_165246.jpg

Date and Time: Around 4:50 PM on July 1, 2025

Location and Temperature:

  • Back of the room 1119, around the working station: 85.7 °F
  • Front of the room 1119, around the doorway: 83.5 °F
  • Back of the room 1129, around the working station: 79.1 °F
  • In the hallway in front of room 1119: 76.5 °F
Entry  Thu Jul 31 14:26:58 2025, Xuesi Ma, Update, ,  2025-08-07_cleanroom_chart.png

[Tyler, Ma, Christina, Maple, Cece, Mary, Pooyan, Audrey]

We started by cleaning outside of the cleanroom wiping down the cable channel and working our way down while taking the pre-cleaning measurement. We then stated wiping down the inside of clean room and vacuumed, mopped the outside of the cleanroom. Finally, we vacuumed, mopped, and wiped down the floor inside the cleanroom.

Particle Count Measurements:

  • Pre-cleaning (2:00 pm):
    • Zone 3:
      • 0.3 µm: 2707
      • 0.5 µm: 1374
      • 1.0 µm: 249
    • Zone 4:
      • 0.3 µm: 2207
      • 0.5 µm: 1166
      • 1.0 µm: 374
  • Post-cleaning (4:30 pm):
    • Zone 3:
      • 0.3 µm: 4082
      • 0.5 µm: 2415
      • 1.0 µm: 708
    • Zone 4:
      • 0.3 µm: 1707
      • 0.5 µm: 791
      • 1.0 µm: 416
Entry  Tue Aug 5 11:25:17 2025, Mary, Update, , point absorber and coated aperture in A# point_absorber_A#.pdf

Simulating how point absorber defects on Advanced LIGO mirrors affect cavity performance by modeling a 4km LIGO-like arm cavity with a point absorber fixed at 5cm off-center on the ITM. In this simulation, displaced the laser beam across a 21×21 grid while calculating the deformation, then measuring the resulting power loss in the cavity (~283W circulating power).

Entry  Wed Aug 6 16:31:37 2025, Xuesi Ma, Update, ,  941.jpg942.jpg943.jpg945.jpg946.jpg

Date and Time: Around 4:20 PM on Auguest 6, 2025

Location and Temperature:

  • Back of the room 1119, around the working station: 90.2 °F
  • Front of the room 1119, around the doorway: 85.8 °F
  • Back of the room 1129, around the working station: 93.4 °F
  • Front of the room 1119, around the doorway: 82.3 °F
  • In the hallway in front of room 1119: 77.2 °F
Entry  Tue Aug 12 12:35:19 2025, Tyler, Update, , CyMAC ADC Update CSD_magnitude.pngchi_sq.png
[Christina, Ma, Tyler]

Updated CyMAC measurement, comparing 260 hrs of measurement time vs. 405 hrs.

Entry  Tue Aug 12 13:46:56 2025, Christina, Update, ,  3.png3-1.png
 
Entry  Tue Aug 12 13:49:24 2025, Mary, Update, , point absorber and coated aperture in A# Aug12.pdf
 
Entry  Tue Sep 2 12:34:02 2025, Xuesi Ma, Update, , Updata for self heating effect on HOM 
https://docs.google.com/presentation/d/19I1fx5BLEzYb4Qnc9P4rJnYAvWI8NqE2dsj9gSPyYzg/edit?usp=sharing
Entry  Tue Sep 9 12:01:38 2025, Tyler, Ma, Update, ,  
Slides
Entry  Tue Sep 9 13:08:44 2025, Xuesi Ma, Update, ,  
Slides
Entry  Thu Jan 22 13:12:29 2026, Mary, Update, ,  PA_matem2.pdfPA_maxtem6.pdfmaxtem600.jpgmaxtem2dis.jpgdismaxtem6.jpg
 
Entry  Thu Jan 29 12:46:22 2026, Cece Ochoa, Update, , CE Cavity Design Update (4) 
Update for CE Cavity Arms + Modes https://docs.google.com/presentation/d/1-dXYylkAbNpHR4WVCx9Q8ryL_xGlH-JSSLXEUQg6b7Q/edit?usp=sharing
Entry  Thu Feb 12 12:59:29 2026, Mary, Update, ,  SB_scattering.pdf
 
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