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ID Date Author Typeup Category Subject
  16746   Mon Mar 28 16:25:34 2022 Ian MacMillanUpdateSUSETMY SUS Electronics Replacement - Questions

The point of changing the gains was to return the system to its origional state. ie I wanted the over all gain of the physical components to be the same as when we started. From the CDS side of things nothing else should be changed. The damping filters should remain at their origional values. The cts2um filter was changed to counteract a change in the electronics (replacing them). These changes should cancel eachother out. As for the side control, on 3/4/22 koji reduced the output resistors for the 4 face OSEMs but did not change the the SD one. there fore the SD did not need the same adjustment as the others.

Quote:

After Ian updated the cts2um filters for OSEM, shouldn't the damping gains be increased back by factor of 10 to previos values? Was the damping gain for SIDE ever changed? we found it at 250.

Can you explain why gain_offset filter was required and why this wasn't done for the side coil?

Quote:

I updated the gain of the ct2um filter on the OSEMS for ETMY and decreased their gain by a factor of 9 from 0.36 to 0.04.

I added a filter called "gain_offset" to all the coils except for side and added a gain of 0.48.

together these should negate the added gain from the electronics replacement of the ETMY

 

 

  16748   Tue Mar 29 17:35:54 2022 PacoUpdateSUSDamping fix on BS, AS4, PR2, and PR3

[Ian, Paco]

  • We removed the "cheby" filters from AS4, PR2 and PR3 which had been misplaced after copying from the old SUS models. After removing them, the new SOS damped fine. Note that because of the Input matrices, the filters have to be enabled all at once for the MIMO loop to make sense.
  • We also disabled the "Cheby" filter on BS and saw it damp better. We don't understand this yet, but perhaps it's just a consequence of the many changes in the BSC that have rendered this filter obsolete.
  • we also reduced the damping gains on PR2, PR3 and AS4 to prevent overflow values. After the adjustments the optics were damping fine.
  16751   Fri Apr 1 14:26:50 2022 TegaUpdateOptical LeversSimplified sketch on MC table

Here is an early sketch of the MC table. 

 

Quote:

I have made an editable draw.io diagram of the planned simplified BHD setup on the ITMY table (see attached).  10 pts = 1 inch.

This is very sketchy but easily adjustable since we are removing everything but the ITMY Oplev from that table.

 

  16752   Fri Apr 1 17:02:02 2022 KojiUpdateOptical LeversSimplified sketch on MC table

We are supposed to have BS Oplev Beams. We don't like the shallow angle reflections (i.e. AOI>45deg).

The laser is too big but I suspect the other components are too small. So it'd be check the actual size of the components including the optical mounts that are missing on the figure so far.

  16753   Fri Apr 1 22:22:29 2022 KojiUpdateOptical LeversSimplified sketch on MC table

Possibility to swap BS and ITMX tables:
BS table, which Tega said MC table, is 2ft x 4ft. The ITMX table is 3ft x 5ft and only the central 2ft x 4ft area is used. The area around the BS table is the narrowest for the east arm. We need at least (2+delta) ft of the hallway width so that we can move the instrument. I'm not yet sure if the ITMX table can be placed there without precise investigation.
 

  16755   Mon Apr 4 15:49:06 2022 TegaUpdateOptical LeversSimplified sketch on BS table

I have updated the BS table using feedback from Koji and Paco and the attached pdf document is the latest iteration.

  16761   Thu Apr 7 11:47:22 2022 YehonathanUpdateBHDInitial BHD modeling: AS - LO mode matching

I begin modeling the initial BHD setup using Finesse. I started with copying C1_w_BHD.kat from the 40m/bhd repo and making changes to reflect the current BHD setup:

1. OMCs were removed.

2. Only 1 PD per BHD port was left.

3. Transmission of PR2 was changed to 2.2%. The PRG was calculated to be ~15.5.

4. Actual RoCs of new optics were dialed in (Yesterday me and Paco went into the cleanroom to measure the RoCs and they seem to match the datasheets).

Here's a table comparing the old (design?) RoCs with the new RoCs:

  New RoC Old RoC
LO1 5m 6m
LO2 inf inf
LO3 500mm 750mm
LO4 150mm -450mm
AS1 2m 2.8m
AS2 inf inf
AS3 200mm -2m
AS4 750mm 600mm
PR2 2000m -700m
PR3 1000m 1000m
SR3 1000m -700m

 

The changes looked quite alarming, especially for LO4 and AS3, so I wrote a script to calculate the mode matching between the LO and AS beams called AS_LO_ModeMatching.ipynb and pushed it into the repo. In the notebook a bright AS beam is created by creating a small asymmetry between the arms of ~ 0.003 degrees (~10pm). Amplitude detectors were put at the input ports of the BHD BS to calculate the fields in the AS and LO beams. In particular TEM00, TEM02 and TEM20 were measured for each beam.

The calculation shows that with the old RoCs the mode matching between the LO and AS beams is 99% while for the new RoCs it is ~ 50%.

  16763   Thu Apr 7 20:33:42 2022 TommyUpdateElectronicsRFSoC 2x2 board -- setup for remote work

To access the board remotely through the 40m lab ethernet port, use

ssh -N -L localhost:1137:localhost:9090 xilinx@<ip_address>

Then in the browser go to

localhost:1137/lab

Other SSH commands using different ports or without the -N -L seemed to fail to open Jupyter. This way has been successful thereafter.

Quote:

[Tommy, Paco]

Since last week I've worked with tommy on getting the RFSoC 2x2 board to get some TFs from simple minicircuits type filters. The first thing I did was set up the board (which is in the office area) for remote access. I hooked up the TCP/IP port to a wall ethernet socket (LIGO-04) and the caltech network assiggned some IP address to our box. I guess eventually we can put this behind the lab network for internal use only.

After fiddling around with the tone-generators and spectrum analyzer tools in loopback configuration (DAC --> ADC direct connection), we noticed that lower frequency (~ 1 MHz) signals were hardly making it out/back into the board... so we looked at some of the schematics found here and saw that both RF data converters (ADC & DAC) interfaces are AC coupled through a BALUN network in the 10 - 8000 MHz band (see Attachment #1). This is in principle not great news if we want to get this board ready for audio-band DSP.

We decided that while Tommy works on measuring TFs for SHP-200 all the way up to ~ 2 GHz (which is possible with the board as is) I will design and put together an analog modulation/demodulation frontend so we can upconvert all our "slow" signals < 1MHz for fast, wideband DSP. and demodulate them back into the audio band. The BALUN network is pictured in Attachment #2 on the board, I'm afraid it's not very simple to bypass without damaging the PCB or causing some other unwanted effect on the high-speed DSP.

 

  16764   Thu Apr 7 20:37:06 2022 TommyUpdateElectronicsRFSoC 2x2 Board -- Simple Tone Generator

In the "Tommy" sub folder, I created a new notebook called "SimpleToneGenerator". This tunes the DAC and ADC mixers to a single frequency and reads off the Time Series and Fourier components. We can alos easily check the demodulation scheme and implement butterworth filters to check their function.

  16765   Thu Apr 7 20:41:15 2022 TommyUpdateElectronicsRFSoC 2x2 Board -- Gain Plotter

In this file (under Tommy), we have a notebook which runs through a spectrum of frequencies and determines the gain response of the attached filter. Below we have the output of a high pass filter. We use IQ demodulation to change IQ componets to DC. Then using a butterworth filter, we read out the DC components and determine the gain's magnitude and phase. However, the phase seems very noisy. This is because the oscillators in the different tiles are independent and a random phase is introduced by changing the mixer frequency in individual tiles. To resolve this we need Multi Tile Synchronization or "MTS". 

Original Pynq Support Forum Query: https://discuss.pynq.io/t/rfsoc-2x2-phase-measurement/3892

We also have the code to fit a resposne function using IIRregular, but this is not as useful without proper phase data.

  16766   Thu Apr 7 21:15:04 2022 YehonathanUpdateBHDInitial BHD modeling: AS - LO mode matching

Ok, it turns out these optics were purchased on purpose, as this elog shows. Jon considered building a mode-matching telescope with stock optics as an initial step before purchasing the custom optics (referred to as "design" optics in my elog).

I dialed in the new distances between the optics into the .kat file as described in this elog and pushed the changes to the repo. With the new distances, I got mode-matching of 87% for the full IFO and 89% for FPMI so there's probably no need to worry as the mode-matching with these optics was already designed.

Quote:

I begin modeling the initial BHD setup using Finesse. I started with copying C1_w_BHD.kat from the 40m/bhd repo and making changes to reflect the current BHD setup:

1. OMCs were removed.

2. Only 1 PD per BHD port was left.

3. Transmission of PR2 was changed to 2.2%. The PRG was calculated to be ~15.5.

4. Actual RoCs of new optics were dialed in (Yesterday me and Paco went into the cleanroom to measure the RoCs and they seem to match the datasheets).

Here's a table comparing the old (design?) RoCs with the new RoCs:

  New RoC Old RoC
LO1 5m 6m
LO2 inf inf
LO3 500mm 750mm
LO4 150mm -450mm
AS1 2m 2.8m
AS2 inf inf
AS3 200mm -2m
AS4 750mm 600mm
PR2 2000m -700m
PR3 1000m 1000m
SR3 1000m -700m

 

The changes looked quite alarming, especially for LO4 and AS3, so I wrote a script to calculate the mode matching between the LO and AS beams called AS_LO_ModeMatching.ipynb and pushed it into the repo. In the notebook a bright AS beam is created by creating a small asymmetry between the arms of ~ 0.003 degrees (~10pm). Amplitude detectors were put at the input ports of the BHD BS to calculate the fields in the AS and LO beams. In particular TEM00, TEM02 and TEM20 were measured for each beam.

The calculation shows that with the old RoCs the mode matching between the LO and AS beams is 99% while for the new RoCs it is ~ 50%.

 

  16767   Fri Apr 8 16:03:58 2022 ranaUpdateElectronicsRFSoC 2x2 board -- setup for remote work & BALUN saga

Seems like it should be possible to just remove the transformer (aka as a BALUN ... BALanced, UNbalanced), or replace it with a lower frequency part. Its just a usual mini-circuits part. Maybe you can ask Chris Stoughton about this and ask Tommy to checkout some of the RFSoC user forums for how to go to DC.

Quote:
 

After fiddling around with the tone-generators and spectrum analyzer tools in loopback configuration (DAC --> ADC direct connection), we noticed that lower frequency (~ 1 MHz) signals were hardly making it out/back into the board... so we looked at some of the schematics found here and saw that both RF data converters (ADC & DAC) interfaces are AC coupled through a BALUN network in the 10 - 8000 MHz band (see Attachment #1). This is in principle not great news if we want to get this board ready for audio-band DSP.

We decided that while Tommy works on measuring TFs for SHP-200 all the way up to ~ 2 GHz (which is possible with the board as is) I will design and put together an analog modulation/demodulation frontend so we can upconvert all our "slow" signals < 1MHz for fast, wideband DSP. and demodulate them back into the audio band. The BALUN network is pictured in Attachment #2 on the board, I'm afraid it's not very simple to bypass without damaging the PCB or causing some other unwanted effect on the high-speed DSP.

 

  16769   Mon Apr 11 11:00:30 2022 JancarloUpdateVACC1VAC Reboot and Nitrogen tanks

[Paco, JC, Ian, Jordan, Chub]

Checking in the morning, I walked over to the Nitrogen tanks to check the levels. Noticed one tank was empty, so I swapped it out. Chub came over to check the levels and to take note of how many tanks were left available for usage (None). Chub continued to put in a work order for a set of full Nitrogen tanks. We should be set on Nitrogen until Thursday this week (4/14/22).

As for C1VAC, this morning, Paco and I attempted to open the PSL shutter, but the interlock system was tripped so we didn't get any light into the IFO. We traced the issue down to C1VAC being unresponsive. We discussed this may have interlocked as a result of the Nitrogen tanks running out, but we do not believe this was the issue since we would have recieved an email. We tried troubleshooting as much as possible avoiding a reboot, but were unable to solve the issue. In response, we ran the idea of a reboot across Jordan and Ian, where everyone was in agreement, and fixed the system. Restarting c1vac seems to have closed V4, but this didn't cause any issues with the current state of the vacuum system.

After opening the PSL shutter again, we see the laser down the IFO, so we resume alignment work

  16772   Tue Apr 12 09:05:21 2022 JordanUpdateVACNew Pressure Gauge Install/Pump Spool Vent

Today, Tega and I would like to vent the pump spool an dinstall the new FRG-400 Agilent Pressure Gauges (per elog 15703). The attached picture shows the volume needed to be vented highlighted in red, and the gauges that need to be replaced/removed (purple dot next to the name).

The vent plan is as follows:

Open RV2

Open VM3

Open V7

Open V4

Shut down TP2

Install new gauges

Will add to post with updates post vent.

  16773   Wed Apr 13 12:50:07 2022 TegaUpdateVACNew Pressure Gauge Install/Pump Spool Vent

[Jordan, JC, Tega]

We have installed all the FRGs and updated the VAC medm screens to display their sensor readings. The replacement map is CC# -> FRG#, where # in [1..4] and PRP1 -> FRG5. We now need to clean up the C1VAC python code so that it is not overloaded with non-function gauges (CC1,CC2,CC3,CC4,PRP1). Also, need to remove the connection cables for the old replaced gauges.

  16774   Wed Apr 13 15:57:25 2022 Ian MacMillanUpdateCamerasCamera Battery Test

Tested the Nikon batteries for the camera. they are supposed to be 7V batteries but they don't hold a charge. I confirmed this with multi-meter after charging for days. Ordered new ones Nikon EN-EL9

  16775   Wed Apr 13 16:23:54 2022 Ian MacMillanUpdateGeneralSmell in 40m

[Ian, Paco, JC]

There is a strange smell in the 40m. It smells like a chemically burning smell maybe like a shorted component. I went around with the IR camera to see if anything was unusually hot but I didn't see anything. The smell seems to be concentrated at the vertex and down the y-arm

  16776   Wed Apr 13 18:55:54 2022 KojiUpdateCamerasCamera Battery Test

I believe that the Nikon has an exposure problem and that's why we bought the Canon.

 

  16777   Thu Apr 14 09:04:30 2022 JordanUpdateVACRGA Volume RGA Scans

Prior to venting the RGA volume on Tuesday (4/12/2022) I took an RGA scan of the volume to be vented (RGA+TP1 volume+Manual Gate Valve) to see if there was a difference after replacing the manual gate valve. Attached is the plot from 4/12/22, and an overlay plot to complare 4/12/22 to 12/10/2021, when the same volume was scanned with the old (defective) manual gate valve.

There is a significant drop in the ratio O2 compared the the nitrogen peak and reduced Argon (AMU 40) which indicates there is no longer a large air leak.

12/10/21 N2/O2 ratio ~ 4 (Air 78%N2 / 21%O2)

4/12/22 N2/O2 ratio ~ 10      

There is one significant (above noise level) peak above AMU 46, which is at AMU 58. This could possibly be acetone (AMU 43 and 58) but overall the new RGA Volume scans look significantly better after the manual gate valve replacement. Well done!

  16782   Fri Apr 15 11:59:16 2022 YehonathanUpdateIOOIMC completely misaligned

Came this morning, opened the PSL and there was not even a beam on the MC REFL.

Looking at the big monitor it seems like the WFS signals went through the roof during the "auto-alignment" night session.

I restored the MC alignment from before the misalignment happen and wait for the SUS to damp. Once the RMS values went below 200 I enabled the watchdog and the coil outputs.

I opened the PSL shutter and the IMC locked immediately. I turned on the WFS servo and the MC REFL DC went down to 0.3. I run the WFS relief script.

  16784   Mon Apr 18 15:17:31 2022 JancarloUpdateGeneralTool box and Work Station Organization

I cleaned up around the 40 m lab. All the Laser Safety Glasses have been picked up and placed on the rack at the entrance.

Some miscellaneous BNC Connector cables have been arranged and organized along the wall parallel to the Y-Tunnel.

Nitrogen tanks have been swapped out. Current tank is at 1200 psi and the other is at 1850 psi.

The tool box has been organized with each tool in its specified area.

  16785   Mon Apr 18 16:09:07 2022 YehonathanUpdateBHDBHD Readout simulation

I'm planning on simulating the BHD readout noise in a manner very similar to the ALS noise model using Simulink. I've made a sketch of the model for the longitudinal DOFs (attached). A model for ASC will be similar but with more measurement devices (OpLevs, QPDs, WFSs).

I'm not pretending to simulate everything in this diagram on the first go, it is just a sketch of the big picture.

  16787   Mon Apr 18 23:22:39 2022 KojiUpdateGeneralTool box and Work Station Organization

Whoa! Thanks!

  16788   Tue Apr 19 18:10:10 2022 PacoUpdateBHDPart V of BHR upgrade - POX11 path, LO path, and ITMX Oplev

[Yuta, Paco]

We set up POX11 beam path from ITMX chamber to the ITMX in-air table. To do this, we first identified the POX reflection on the ITMX chamber, and then steered the POXM1 (in the BSC) by hand until we cleared the viewport. We also checked that the POX beam is centered on POXM1.

We then decided to slide the LO1 YAW to clear the LO beam path, which was otherwise clipping on the PR2 SOS. The slider (DAC limited) range of -25000 counts was barely enough to clear the SOS comfortably and avoid hitting the POXM1. The LO beam is now hitting LO2 mirror, so LO alignment can proceed from BSC and ITMY chamber.

Finally, we aligned the input ITMX Oplev beam to ITMXOL2, then ITMX, then to ITMXOL2, and finally into the ITMX in-air optical table. We took some photos of the Oplev beam (see Attachments) to note their position.

By the end of in-vacuum work there was still some flashing in the arm cavities, but fine alignment is required.


After closing the ITMX Chamber, and BSC, we moved on to center the ITMXOL beam. We accomplished this by using two mirrors instead of one as was previously the case. This relaxed the angle of incidence a little, but we had to change the path and the position of the QPD. The QPD sum reads ~ 6600 counts versus the ~ >8000 counts it read right before the vent. One attempt at closing the OL loop, and the ITMX starting oscillating in YAW (PIT was ok), so we realized that maybe we flipped the order in which the OL1 / OL2 mirror were arranged and so the YAW loop needed to flip its sign. Indeed after changing the C1:SUS-ITMX_OL_YAW_GAIN from -6.0 to 6.0 the OL_YAW loop is stable.

  16789   Wed Apr 20 08:20:22 2022 PacoUpdateBHDPart V of BHR upgrade - PR2 weirdness

Yesterday, I tried tuning the PR2 damping gains by increasing the gain until the damping gave the ~5 oscillations (by watching the damped motion using StripTool, and keeping an eye on the PD var). I noticed that often when I changed the gain, some OSEM sensors shifted (gained an offset!!) and the PD var values changed, typically increasing at higher damping gains. I reverted the changes until the PD var looked "normal" again (~ 2 mV) but it is hard to imagine that the damping filters can have such a "DC" effect, given the shape comprises single zero at 0 Hz (and pole at 30 Hz).

  16790   Wed Apr 20 14:56:06 2022 TommyUpdateElectronicsRFSoC 2x2 board -- setup for remote work & BALUN saga

Here are a few options for replacement BALUNs from Mini Circuits and specs:

Current. TCM1-83X+, 10-8000 MHz, 50 Ohms, Impedance Ratio 1, Configuration K

1. Z7550-..., DC-2500 MHz (some DC-2300), 50/75 Ohms, Impedance Ratio 1.5, Configuration Q. There are various types of the Z7550 which have different connectors (SMA and BNCs). These have much larger dimensions than the TCM1-83X. Can handle up to 5A DC current with matching loss 0.6 dB.

2. SFMP-5075+, DC-2500 MHz, 50/75 Ohms, Impedance Ratio 1.5, Configuration D. This is an SMA connected BALUN. It can handle 350mA, has a matching loss 0.4 dB, and has 1W power handling.

Quote:

Seems like it should be possible to just remove the transformer (aka as a BALUN ... BALanced, UNbalanced), or replace it with a lower frequency part. Its just a usual mini-circuits part. Maybe you can ask Chris Stoughton about this and ask Tommy to checkout some of the RFSoC user forums for how to go to DC.

Quote:
 

After fiddling around with the tone-generators and spectrum analyzer tools in loopback configuration (DAC --> ADC direct connection), we noticed that lower frequency (~ 1 MHz) signals were hardly making it out/back into the board... so we looked at some of the schematics found here and saw that both RF data converters (ADC & DAC) interfaces are AC coupled through a BALUN network in the 10 - 8000 MHz band (see Attachment #1). This is in principle not great news if we want to get this board ready for audio-band DSP.

We decided that while Tommy works on measuring TFs for SHP-200 all the way up to ~ 2 GHz (which is possible with the board as is) I will design and put together an analog modulation/demodulation frontend so we can upconvert all our "slow" signals < 1MHz for fast, wideband DSP. and demodulate them back into the audio band. The BALUN network is pictured in Attachment #2 on the board, I'm afraid it's not very simple to bypass without damaging the PCB or causing some other unwanted effect on the high-speed DSP.

 

model_no case_style single2single single2bal bal2bal center_tap dc_iso freq_low freq_high impedance imped_ratio interface tech config
SFMP-5075+ FF1891 Y N N N N DC 2500 50/75 1.5 CON CORE & WIRE D
TCM1-83X+ DB1627 N Y Y N N 10 8000 50 1 SMT CORE & WIRE K
Z7550-BFNF+ H795-14 Y N N N N DC 2500 50/75 1.5 CON CORE & WIRE Q
Z7550-BMBF+ QP1876-1 Y N N N N DC 2300 50/75 1.5 CON CORE & WIRE D1
Z7550-BMNF+ QP1876 Y N N N N DC 2500 50/75 1.5 CON CORE & WIRE Q
Z7550-FFNM+ H795-1 Y N N N N DC 2300 50/75 1.5 CON CORE & WIRE Q
Z7550-FFSF+ H557-1 Y N N N N DC 2500 50/75 1.5 CON CORE & WIRE Q
Z7550-FMSF+ H795-3 Y N N N N DC 2300 50/75 1.5 CON CORE & WIRE Q
Z7550-FMSFDC+ H795-3 Y N N N Y 1 2500 50/75 1.5 CON CORE & WIRE Q
Z7550-NFNF+ H795-10 Y N N N N DC 2500 50/75 1.5 CON CORE & WIRE D1
Z7550-NMNF+ H795-4 Y N N N N DC 2300 50/75 1.5 CON CORE & WIRE Q
  16791   Wed Apr 20 16:11:08 2022 KojiUpdateSUSOutpur resistors updated for LO1 coil drivers / for SR2, LO2, AS1, and AS4 in progress

[JC Koji]

To give more alignment ranges for the SUS alignment, we started updating the output resistors of the BHD SUS coil drivers.
As Paco has already started working on LO1 alignment, we urgently updated the output Rs for LO1 coil drivers.
LO1 Coil Driver 1 now has R=100 // 1.2k ~ 92Ohm for CH1/2/3, and LO1 Coil Driver 2 has the same mod only for CH3. JC has taken the photos and will upload/update an elog/DCC.

We are still working on the update for the SR2, LO2, AS1, and AS4 coil drivers. They are spread over the workbench right now. Please leave them as they're for a while.
JC is going to continue to work on them tomorrow, and then we'll bring them back to the rack.

  16792   Wed Apr 20 18:50:03 2022 KojiUpdateBHDPart V of BHR upgrade - PR2 weirdness

It seemed that it comes from the servo oscillation. This does not happen when the output limitters were set to be 100-ish. But even so the gains looked quite low.

I turned on the Cheby rool-offs for all the DOFs, and this allowed me to increase the damping gain A LOT.
The gains were 2~5 but now they are now 20-25 for the face OSEMs and 150 for SD.

The attached is the example of the damping when all the damping loops are on.

I think we need to tune the servo loops carefully for all the SUSs by actually looking at the openloop transfer functions rather than a personal feeling. => To Do

  16793   Thu Apr 21 10:35:23 2022 KojiUpdateCDSDAQ seemed down

Yesterday, when I worked on the damping servo, I found that any of the daqvtools (ndscope, dtt, dataviewer,...) is not available.  We may need to restart the fb and rt machines.

  16794   Thu Apr 21 11:31:35 2022 JCUpdateVACGauges P3/P4

[Jordan, JC]

It was brought to attention during yesterday's meeting that the pressures in the vacuum system were not equivalent althought the valve were open. So this morning, Jordan and I reviewed the pressure gauges P3 and P4. We attempted to recalibrate, but the gauges were unresponsive. Following this, we proceeded to connect new gauges on the outside to test for a calibration. The two gauges successfully calibrated at atmosperic pressure. We then proceeded to remove the old gauges and install the new ones. 

  16795   Thu Apr 21 15:22:44 2022 KojiUpdateSUSOutpur resistors updates for SR2, LO2, AS1, and AS4 done

[JC Koji]

Quick report: JC has done all the mods for the coil driver circuit in the morning and we worked on the reinstallation of them in the afternoon.
I'll check the damping loops / sus servo settings. JC is going to make an ELOG entry and DCC updates for more precise record of the mods.

  16796   Thu Apr 21 16:36:56 2022 TegaUpdateVACcleanup work for vacuum git repo

git repo - https://git.ligo.org/40m/vac

Finally incorporated the FRGs into the main modbusIOC service and everything seems to be working fine. I have also removed the old sensors (CC1,CC2,CC3,CC4,PTP1,IG1) from the serial client list and their corresponding EPICS channels. Furthermore, the interlock service python script has been updated so that all occurrence of old sensors (turns out to be only CC1) were replaced by their corresponding new FRG sensor (FRG1) and a redundnacy was also enacted for P1a where the interlock condition is replicated with P1a being replaced with FRG1 because they both sense the main volume pressure.

  16797   Thu Apr 21 16:49:01 2022 PacoUpdateBHDPart V of BHR upgrade - BS Oplev + LO1 offset

[Paco, JC, Yuta]

We aligned the BS oplev using the new BSOL mirror pair. The main change is now the AOI of the oplev on the BS is quite normal. The output beam in the in-air table was quite large (diverging?) so we had to place a short FL lens in front of the QPD.


Separately, I added the LO1 YAW offset of ~ -2500 counts (before the coil driver changes it was -24500 counts) and saw LO beam hitting LO2. This means the alignment of the LO beam can move downstream.

  16799   Thu Apr 21 18:18:42 2022 yehonathanUpdateBHDPOX Alignment

{Yehonathan, Paco}

BS, ITMX and ETMX were aligned to get flashing in the X arm.

I aligned the POX beam on the ITMX table using a mixture of the old POP and POX optics. The beam was stirred to the POX11 RFPD. We measure the DC power using a scope but we see nothing. We went and saw that the POX11 cable was not connected to RF rack so we connected it along with some other RFPD cables.

We return but there is still no DC. We ndscope C1:LSC-POX11_I_ERR_DQ C1:LSC-POX11_Q_ERR_DQ and maximize the signal (attachment). The readout is very weak though. It should be as strong as POY which we already observed to have good SNR.

We also noticed that the one of the beam dumps for the POX RFPD is not glued and easily falls down.

  16800   Thu Apr 21 18:42:47 2022 TegaUpdateBHDPart V of BHR upgrade - Align LO and AS beams to BHD BS

[Tega, Yuta, Paco]

We tried aligning the LO and AS beams on to the BHD beamsplitter. During the alignment process, we noticed that the damping loop for AS1 was not working. Paco drew our attention to the fact that the UR OSEM signal was alway close to zero, so we checked to ensure that the magnet was still within the OSEM recess and it looks OK. Next we checked the electrical connection at the interface between the copper OSEM cables to the blue in-vacuum flat cable and this too looks alright also. Since the AS1 coil driver was recently modified, it is possible we might find the problem there, so I'll ask Koji about this.


So Koji clarified that the coil driver board and SATAMP boards are different so we should connect this issue to the coil driver board.

  16801   Thu Apr 21 20:33:31 2022 KojiUpdateBHDAS1 UR OSEM problem localized in the chamber

Tega and Paco reported that the UR OSEM of AS1 lost the response.

- I have checked the LED MON (left) of the satellite amp for AS1. CH1/2/3 had 5V -> This indicates that the OSEM LEDs are (most likely) functioning.
- Then I went to the ITMY flange and connected the OSEM emulator instead of the Dsub25 cable. The attachment shows that the UR OSEM LED/PD worked fine with the OSEM emulator. WIth the vacuum flange connected it lost the response.

This indicates that the AS1 UR OSEM problem is localized in the chamber. Please check if the DSUB pins are touching the table or something else.

 

  16802   Fri Apr 22 07:01:58 2022 JcUpdateCoil DriversAdding Resistors and Reinstalling

[Koji, JC]

Coil Drivers LO2, SR2, AS4, and AS1 have been updated a reinstalled into the system. 

LO2 Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3        Unit: S2100008

LO2 Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3                    Unit: S2100530

SR2 Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3        Unit: S2100614

SR2 Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3                    Unit: S2100615

AS1 Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3        Unit: S2100610

AS1 Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3                    Unit: S2100611

AS4 Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3        Unit: S2100612

AS4 Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3                    Unit: S2100613

  16803   Fri Apr 22 12:03:09 2022 TegaUpdateBHDAS1 UR OSEM problem localized in the chamber

[JC, Tega, Ian, Paco]

We found that the UR cable was clamped to the table by one of the ITMY OPLEV steering mirror mounts that was recently installed. After freeing the cable, the UR signal is now active again.

Quote:

This indicates that the AS1 UR OSEM problem is localized in the chamber. Please check if the DSUB pins are touching the table or something else.

 

  16804   Fri Apr 22 12:09:51 2022 AnchalUpdateCoil DriversPlease update DCC pages

Nice. Please put this information on the DCC pages of the coil driver units. You'll find links to all the units in this document tree LIGO-E2100447. For each page, click on "Change Metadata" from the left panel and add the change made to the resistor (including the resistor name on PCB, previous and new value), and add a link to your previous elog post which has more details like photos, to "Notes and Changes", and upload an updated version of the circuit schematic by creating an annotation in the previous circuit schematic pdf. Every unit that has a serial number in the lab has a DCC page (if not, we should create one) where we should track all such hard changes.

 

  16805   Fri Apr 22 12:15:08 2022 AnchalUpdateBHDCable post installation

If someone gets time, let's put in all the cable posts and clean up our cable routing on the tables.

 

  16806   Fri Apr 22 14:14:33 2022 JordanUpdateVACTP3 Forepump tip seal replacement

Jordan, JC

While the pumpspool is vented, I thought it would be a convenient time to change out the tip seal on the TP3 forepump. This one had not been changed since 2018, so as preventative maintence I had JC remove the pump and begin cleaning/installing the new tip seal.

Unfortunately the tip seal broke, but I have ordered another. We should have this pump ready to go late next week. If one is needed sooner, there is a spare IDP 7 pump we can install as the TP3 forepump.

  16807   Sun Apr 24 13:17:08 2022 TommyUpdateElectronicsNew RFSoC2x2 Overlay

We recieved an overlay from Chris Stoughton which he used for a ZCU11 board. The overlay is supposed to be compatible with the RFSoC 2x2 and help enable the Multi-Tile Synchronization (MTS) we need. He also provides a .py with the necessary low level connection to the board and its memory along with a few sample notebooks.

Progress So Far:

  • The overlay loads properly and in reasonable time. 
  • We can set the mixer and dac frequencies. However, it is unclear what event_src Chris wanted for the adc mixers. It seems that he was using event_src_immediate (possibly unintenionally) which is not an available adc mixer setting in our board. Instead, we set the event source to "Tile" and will later determine if this is an issue.
  • We then go to get data from the buffer. There are two functions called: capture and transfer. These are called on the pynq DMA. Capture runs fine but we get stuck during the transfer at dma.revchannel.wait(). This issue has not been resolved.
  16808   Mon Apr 25 14:19:51 2022 JCUpdateGeneralNitrogen Tank

Coming in this morning, I checked on the Nitrogen tanks to check the level. One of the tanks were empty, so I went ahead and swapped it out. One tank is at 946 PSI, the other is at 2573 PSI. I checked for leaks and found none.

  16809   Mon Apr 25 14:49:02 2022 KojiUpdateGeneralNitrogen Tank

For your (and mine) info:

N2 pressure can be monitored on the 40m summary page: https://nodus.ligo.caltech.edu:30889/detcharsummary/day/20220425/vacuum/
(you need to hit "today" to go to the current status)

 

  16810   Mon Apr 25 16:57:57 2022 AnchalUpdateBHDCable post installation

[Anchal, Tega, JC]

We installed cable posts in ITMY, BS, and ITMX chambers for all the new suspensions. Now, there is no point where the OSEM connections are hanging freely.

In BS chamber, we installed one post for LO2 near the north edge of the table and another post for PR3 on the Western edge with the blue cable running around the table on the floor.

In ITMY chamber, we installed the cable post in between AS1 and AS4 with the blue cables running around the table on the floor. This is to ensure the useful part of the table remains empty for future and none of the OSEM cables are taught in air.

 

  16811   Mon Apr 25 17:24:06 2022 AnchalUpdateCDSDAQ still down

I investigated this issue today. At first, it seemed that only new suspension testpoints are inaccessible. I was able to use diaggui for a measurement on MC2. The DAQ network cable between 1X4 and 1Y1 was tied and is very taught now (we should relieve this as soon as possible, best solution is to lay down a longer cable over the bridge). My hypothesis is that the DAQ network might have broken while tying this cable and it probably did not come back since then.

The simplest solution would have been to restart c1su2 models. As I restarted those models though, I found that c1lsc and c1sus models failed. This is very unusual as c1su2 models are independent and share nothing with the other vertex models. So I had to restart all the FE computers eventually. But this did not solve the issue. Worse, now the DAQ isn't working for the vertex machiens as well.

Next step was to try restarting fb1 itself. We switched off all the FE computers, restarted fb1, stopped daqd_* processes, reloaded gpstime module, restarted open-mx, mx, nds and daqd_* process. But the mx.service failed to load with following error message:

● mx.service - LSB: starts MX driver for Myrinet card
   Loaded: loaded (/etc/init.d/mx)
   Active: failed (Result: exit-code) since Mon 2022-04-25 17:18:02 PDT; 1s ago
  Process: 4261 ExecStart=/etc/init.d/mx start (code=exited, status=1/FAILURE)

Apr 25 17:18:02 fb1 mx[4261]: Loading mx driver
Apr 25 17:18:02 fb1 mx[4261]: insmod: ERROR: could not insert module /opt/mx/sbin/mx_mcp.ko: File exists
Apr 25 17:18:02 fb1 mx[4261]: insmod: ERROR: could not insert module /opt/mx/sbin/mx_driver.ko: File exists
Apr 25 17:18:02 fb1 systemd[1]: mx.service: control process exited, code=exited status=1
Apr 25 17:18:02 fb1 systemd[1]: Failed to start LSB: starts MX driver for Myrinet card.
Apr 25 17:18:02 fb1 systemd[1]: Unit mx.service entered failed state.

(Ignore the timestamp above, I ran the command again to capture the error message.)

However, I was able to start all the FE models without any errors and daqd processes are also all running without showing any errors. Everything is green in CDS screen with no error messages. But the only thing still wrong is mx.service which is not running.

From my limited knowledge and experience, mx.service is a one-time script that mounts mx devices in /dev and loads the mx driver. I tried running the script /opt/mx/sbin/mx_start_stop :

controls@fb1:/opt/mx/sbin 1$ sudo ./mx_start_stop start
Loading mx driver
insmod: ERROR: could not insert module /opt/mx/sbin/mx_mcp.ko: File exists
insmod: ERROR: could not insert module /opt/mx/sbin/mx_driver.ko: File exists

This gave the same error. On searching little bit online, "insmod: ERROR; cound not insert module" error comes up when the kernel version of the driver doesnot match the Linux kernel (whatever that means!). Such deep issues should not appear out of nowhere in a previosuly perfectly runnig system. I'll check around more what changed in fb1, network cables etc.

  16812   Mon Apr 25 18:00:03 2022 Ian MacMillanUpdateUpgradeCable supports update

I have designed new cable supports for the new ribbon cables running up the side of the tables in the vacuum chambers. 

The clamps that I have designed (shown in basic sketch attachment 1) will secure the cable at each of the currently used cable supports. 

The support consists of a backplate and a frontplate. The backplate is secured to the leg of the table using a threaded screw. The frontplate clamps the cable to the backplate using two screws: one on either side. Between two fascinating points, the cable should have some slack. This should keep the cable from being stiff and help reduce the transfer of seismic noise to the table. 

It is possible to stack multiple cables in one of these fasteners. Either you can put two cables together and clamp them down with one faceplate or you can stack multiple faceplates with one cable between each faceplate. in this case the stack would go backplate then cable then faceplate then cable then the second faceplate. this configuration would require longer screws.

The exact specifics about which size screws and which size plates to use still have not been measured by me. But it will happen

  16813   Tue Apr 26 16:23:22 2022 TommyUpdateElectronicsRFSoC2x2 MTS

We connected a 8 MHz signal generator to the device in order to sync up the ADCs and DACs and hopefully get phase data. 

Some things to note:

  • RF Manual (143)- Need to use XRFDC SYSREF for update event
  • RF Manual (171)- Synchronization steps require us to first enable all clocks and sysref generators (via xrfdc package)
  • RF Manual (173)- Sysref requirments, not clear if PL is syncing as needed.
  • RF Manual (181)- XRFDC example code, see also https://github.com/Xilinx/embeddedsw/blob/master/XilinxProcessorIPLib/drivers/rfdc/examples/xrfdc_mts_example.c

Xilinx RF Manual: https://docs.xilinx.com/v/u/2.4-English/pg269-rf-data-converter

  16814   Wed Apr 27 10:05:55 2022 JCUpdateCoil DriversCoil Drivers Update

18 (9 pairs) Coil Drivers have been modified. Namely ETMX/ITMX/ITMY/BS/PRM/SRM/MC1/MC2/MC3.

 

ETMX Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3        S2100624                     ETMX Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3      S2100631

ITMX Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3         S2100620                      IMTX Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3      S2100633

ITMY Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3         S2100623                   ITMY Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3      S2100632

BS Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3            S2100625                     BS Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3      S2100649

PRM Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3         S2100627                      PRM Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3      S2100650

SRM Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3         S2100626                        SRM Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3      S2100648

MC1 Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3         S2100628                        MC1 Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3      S2100651

MC2 Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3       S2100629                        MC2 Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3         S2100652

MC3 Coil Driver 1 (UL/LL/UR)now has R=100 // 1.2k ~ 92Ohm for CH1/2/3        S2100630                        MC3 Coil Driver 2 (LR/SD)now has R=100 // 1.2k ~ 92Ohm for CH3         S2100653

 

 

Will be updating this linking each coil driver to the DCC

  16816   Thu Apr 28 09:12:18 2022 AnchalUpdateBHDRestoring arm alignment

This would be a daily first task in the morning. We'll need to check the status of arm alignment and optimize it back to maximum every morning for the rest of the day's work.

Today, when I came, on openin gthe PSL shutter, IMC was aligned good, both arms were flashing but YARM maximum transmission count was around 0.7 (as opposed to 1 from yesterday) and XARM maximum transmission count was 0.5 (as opposed to 1 from yesterday). I did not change the input alignment to the interferometer. I only used ITMY-ETMY to regain flashing count of 1 on YARM and used BS and tehn ITMX-ETMX to regain flashing count of 0.9 to 1 in XARM.

Even thought the oplevs were centered yesterday, I found the oplev had drifted from the center and the optimal position also is different for all ooptics except EMTY and BS. It is worth nothign that in optimal position both PIT and YAW of ITMY and ITMX are off by 70-90 uradians and ETMX Pit oplev is off by 55 uradians.

 

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