 Tue Jul 12 09:25:09 2022, rana, Update, IOO, IMC WFS
|
MC WFS Demod board needs some attention.
Tomislav has been measuring a very high noise level in the MC WFS demod output (which he promised to elog today!). I thought this was a bogus
measurement, but when he, and Paco and I tried to measure the MC WFS sensing matrix, we noticed that there is no response in any WFS, although there are |
|
Tue Jul 12 13:59:12 2022, rana, Summary, Computers, process monitoring: Monit
|
I've installed Monit on megatron and nodus just now, and will set it up to monitor some of our common processes.
I'm hoping that it can give us a nice web view of what's running where in the Martian network. |
|
Tue Jul 12 18:35:31 2022, Cici Hanna, Summary, General, Finding Zeros/Poles With Vectfit
|
Am still working on using vectfit to find my zeros/poles of a transfer function - now have a more specific project in mind, which is to have a Red Pitaya
use the zero/pole data of the transfer function to find the UGF, so we can check what the UGF is at any given time and plot it as a function of time to
see if it drifts (hopefully it doesn't). Wrestled with vectfit more on matlab, found out I was converting from dB's incorrectly (should be 10^(dB/20)....) |
|
Tue Jul 12 19:46:54 2022, Paco, Summary, ALS, How (not) to take NPRO PZT transfer function
|
[Paco, Deeksha, rana]
Quick elog for this evening:
Rana disabled MC servo .
Slow loop also got disengaged.
AUX PSL beatnote is best taken with *free running lasers* |
|
Wed Jul 13 12:49:25 2022, Paco, Summary, SUS, SUS frozen
|
[Paco, JC, Yuta]
This morning, while investigating the source of a burning smell, we turned off the c1SUS 1X4 power strip powering the sorensens. After this,
we noticed the MC1 refl was not on the camera, and in general other vertex SUS were misaligned even though JC had aligned the IFO in the morning to almost |
Tue Jul 12 14:56:17 2022, Tomislav, Summary, Electronics, Electronics noise measurements 23x
|
[Paco, Tomislav]
We measured the electronics noise of the demodulation board, whitening board, and ADC for WFSs, and OPLEV board and ADC for DC QPD in MC2 transmission.
We were using SR785. |
 Wed Jul 13 13:26:44 2022, rana, Summary, Electronics, Electronics noise measurements
|
as I said to you yesterday, I don't think image 2a shows the output of the demod board. The
output of the demod board is actually the output connector ON the demod board. What you are showing in 2a, is the signal that goes from the whitening board
to the ADC I believe. I may be msitaken, so please check with Tega for the signal chain. |
|
Wed Jul 13 18:58:17 2022, Koji, Update, IOO, IMC suspecion
|
This is just my intuition but the IMC servo seems not so optimized. I can increase the servo gain by 6~10dB easily. And I couldn't see that the PC
drive went mad (red) as I increase the gain (=UGF).
The IMC needs careful OLTF measurements as well as the high freq spectrum observation. |
|
Thu Jul 14 19:09:51 2022, rana, Update, General, EQ recovery
|
There was a EQ in Ridgecrest (approximately 200 km north of Caltech). It was around 6:20 PM local time.
All the suspensions tripped. I have recovered them (after some struggle with the weird profusion of multiple conflicting scripts/ directories
that have appeared in the recent past...) |
|
Thu Jul 14 19:56:15 2022, rana, Update, IOO, mc wfs demod
|
It looks like Tomislav's measurements of the WFS demod board noise were actually of the cable that goes from the whitening to the ADC. So the huge
low frequency excess that he saw is not due to wind, but just the inverse whitening of the digital system?
In any case, today, I looked at the connections from the Whitening to the ADC. It goes through an interface chassis to go from ribbon to SCSI. |
|
Wed Jul 13 07:16:48 2022, JC, Update, Electronics, Checking Sorensen Power Supplies
|
[JC]
I went around 40m picking up any Sorensens that were laying around to test if they worked, or in need of repair. I gathered up a total of 7 Sorensens
and each one with a Voltmeter. I made sure the voltage would rise on the Sorenson as well as the voltmeter, maxing out at ~33.4 Volts. For the current, |
|
Fri Jul 15 12:21:58 2022, JC, Update, Electronics, Checking Sorensen Power Supplies
|
Of the 7 Sorenson Power Supplies I tested, 5 are working fine, 1 cannot output voltage more than 20 Volts before shorting, and other does not output
current. Six Sorensons are behind the X-Arm.
|
|
Fri Jul 15 16:20:16 2022, Cici Hanna, Update, General, Finding UGF
|
I have temporarily abandoned vectfit and aaa since I've been pretty unsuccessful with them and I don't need poles/zeroes to find the unity
gain frequency. Instead I'm just fitting the transfer function linearly (on a log-log scale). I've found the UGF at about 5.5 kHz right now, using
old data - next step is to get the Red Pitaya working so I can take data with that. Also need to move this code from matlab to python. Uncertainty's propagated |
|
Sat Jul 16 02:44:10 2022, Koji, Update, IOO, IMC servo tuning
|
I wasn't sure how the IMC servo was optimized recently. We used to have the FSS over all gain (C1:PSL-FSS_MGAIN) of +6dB a few years back. It is
not 0dB. So I decided to do a couple of measurements.
1) Default setting: |
|
Mon Jul 11 11:56:40 2022, Yehonathan, Update, BHD, MICH AS55 noise budget
|
I calculated a noise budget for the MICH using AS55 as a sensor. The calculation includes closed-loop TF calculations.
The notebook and associated files can be found on https://git.ligo.org/40m/bhd/-/blob/master/controls/compute_MICH_noisebudget.ipynb.
Attachment 1 shows the loop diagram I was using. The equation describing the steady-state of the loop is |
|
Tue Jul 12 09:14:50 2022, rana, Update, BHD, MICH AS55 noise budget
|
Looking good:
I think the notches you see in he measured noise are a clue as to the excess noise source. You can try turning some notches on/off.
Laser
noise does matter a bit more subtley: the low freq noise couples to AS55 through the RMS deviation of the MICH loop from the zero crossing, and the noise |
|
Wed Jul 13 10:54:39 2022, Yehonathan, Update, BHD, MICH AS55 noise budget
|
I fixed some mistakes in the budget:
1. The BS pendulum resonance was corrected from 0.8Hz to 1Hz
2. Added missing X3 filter in the coil filters |
|
Wed Jul 13 13:30:48 2022, Yehonathan, Update, BHD, add Laser RIN to MICH budget
|
the main laser noise coupling for a Michelson is because of the RIN, not the frequency noise. You can measure the RIN, in MC trans or at the AS port
by getting a single bounce beam from a single ITM. |
|
Mon Jul 18 16:49:57 2022, Yehonathan, Update, BHD, add Laser RIN to MICH budget
|
I measured the RIN by taking the spectrum of C1:MC_TRANS_SUMFILT_OUT and dividing it by the mean count on that channel (~13800 cts).
Attachment 1 shows the result.
I updated the MICH AS55 noise budget but got a very low contribution (gold trace in attachment 2). |
|
Mon Jul 18 18:33:38 2022, Koji, Update, BHD, add Laser RIN to MICH budget
|
You should measure the coupling by noise injection. Noise budgeting does not need any modeling:
1) Measure the power spectrum density of the target signal (i.e. DARM) and the source noise (i.e. RIN this case)
2) Calibrate both using a calibration peak to convert 1) into the physical units (m/rtHz, 1/rtHz, etc) |
|
Tue Jul 19 17:18:34 2022, JC, Update, Electronics, New Coil Driver on Rack 1X3
|
[Yehonathan, JC]
Yehonathan and I began to put the electronics on Rack 1X3. To do this, we had to move the monitor over the the PD testing table. Before mounting
the Coil Drivers, we added numbers to the spaces to follow the rack plan Koji has provided. The drivers which have been mounted are PRM (Slots 10,11), |
|
Fri Jul 22 17:43:19 2022, Koji, Update, General, Obtained a functional CRT
|
[Koji Paco]
Koji went to Downs and found a CRT labeled "for 40m Rana?". So I decided to salvage it to the 40m after getting approval from Rich/Todd.
Paco and I tried this unit with the control room CCD signal and it just worked fine. So we can use this as a spare for any purpose in the lab. |
|
Mon Jul 18 04:42:54 2022, Anchal, Update, Calibration, Error propagation to astrophysical parameters from detector calibration uncertainty
|
We can calculate how much detector calibration uncertainty affects the estimation of astrophysical parameters using the following method:
Let be set of astrophysical
parameters (like component masses, distance etc), |
|
Mon Jul 18 15:17:51 2022, Hang, Update, Calibration, Error propagation to astrophysical parameters from detector calibration uncertainty
|
1. In the error propogation equation, it should be \Delta \Theta = -H^{-1} M \Delta \Lambda, instead of the fractional error.
2. For the astro parameters, in general you would need t_c for the time of coalescence and \phi_c for the phase. See, e.g., https://ui.adsabs.harvard.edu/abs/1994PhRvD..49.2658C/abstract.
3. Fig. 1 looks very nice to me, yet I don't understand Fig. 3... Why would phase or amplitude uncertainties at 30 Hz affect the tidal |
|
Tue Jul 19 07:34:46 2022, Anchal, Update, Calibration, Error propagation to astrophysical parameters from detector calibration uncertainty
|
Addressing the comments as numbered:
Yeah, that's correct, that equation normally but it is different if I define bit differently that I did in the code, correct |
|
Sun Jul 24 08:56:01 2022, Hang, Update, Calibration, Error propagation to astrophysical parameters from detector calibration uncertainty
|
Sorry I forgot to put tc & phic in the example.
I modified astroFisherLib.py to include these parameters. Please note that their meaning is that we don't know when the signal happens
and at which phase it merges. |
|
Mon Jul 25 09:37:39 2022, Deeksha, Update, Electronics, Using the DFD to measure PZT TF
|
The DFD was setup to measure the change in beatnote when excited. A long long (128in) cable goes from the SR785 near the DFD all the way to the Xend
AUX which it accordingly excites and the DFD is monitored by the oscilloscope at the other end. This was completed on Friday. The wires and stand have
been moved to the side but the setup is still a bit chaotic. As of writing this post, there is still atleast some minor issue with the setup as we aren't |
|
Mon Jul 25 18:22:30 2022, Deeksha, Summary, Wiki, Measured the PZT TF Successfully 6x
|
Measured the PZT beatnote using the setup mentioned in elog post 17031. Attached is the data taken from 10kHz to 1MHz, decadewise data was also taken
that I'm not including in this post. A_R refers to the transfer function taken of channel A wrt the voltage reference (the swept sine we are inputting
which has an IF of 30kHz). A and B correspond to the I and Q components of the signal taken from the DFD, respectively. I am currently working on plotting |
|
Tue Jul 26 19:50:25 2022, Deeksha, Update, Computer Scripts / Programs, Vector fitting
|
Trying to vectfit to the data taken from the DFD previously but failing horribly. I will update this post as soon as I get anything semi-decent. For
now here is this fit. |
|
Tue Jul 26 21:16:41 2022, Koji, Update, Computer Scripts / Programs, Vector fitting
|
I think the fit fails as the measurement quality is not good enough.
|
|
Wed Jul 27 14:39:04 2022, Deeksha, Update, Electronics, New and improved PZT TF data from the DFD
|
Paco and I messed around with the attenuation of the scope and bandwidth of the IF. We also replaced the BNC T's in the circuits with RF splitters.
We saw some decent improvements to the data. The data is attached and a diagram of the experiment. [We analytically calculated the impedances to avoid
any mismatch taking place]. Working on fitting the data. |
|
Thu Jul 28 13:09:28 2022, yehonathan, Update, BHD, Mode matching considerations
|
The LO beam was found to have a power of 60uW, 10% of the power expected. We are pretty sure about the expectation because the AS beam has a power of
300uW, roughly the expected power. Additionally, the visibility of the MICH fringes in the BHDR is 40%.
If the mode-matching is perfect then we expect the visibility to be |
|
Wed Jul 13 17:30:19 2022, Koji, Update, CDS, Too huge script_archive
|
I wanted to check the script archive to see some old settings. I found that the script archive inflated to huge
volume (~1TB).
The size of the common NFS volume (/cvs/cds) is 3TB. So it is really significant. |
|
Thu Jul 28 15:11:59 2022, Koji, Update, CDS, Too huge script_archive
|
As a result of the following work, the file volume of /cvs/cds was reduced from 3.2TB to 2.2TB, and
/opt/rtcds/caltech/c1/scripts was reduced from 10GB to 1.5GB
/cvs/cds/caltech/scripts_archive was cleaned up. Now the archive files are reduced to have: |
|
Mon Aug 1 17:19:39 2022, Cici, Summary, General, RPitaya Data on Jupyter Notebook
|
Have successfully plotted data from the Red Pitaya on Jupyter Notebook! Have lost years of my life fighting with PyQt. Thanks to Deeksha for heavy
contribution. Next task is to get actually good data (seeing mostly noise right now and haven't figured out how to change my input settings) and then
to go to set up the RPi in the lab. |
|
Wed May 25 16:56:44 2022, Paco, Configuration, BHD, IFO recovery - IMC alignment
|
[Yuta, Paco]
We aligned IMC to recover the IFO progressively. First step was to center the MC REFL beamspot on the camera as well as the WFS DC. Then slide
MC2 and MC3 together. Below are the alignment slider positions before/after. |
|
Wed May 25 17:34:47 2022, yuta, Configuration, BHD, IFO recovery - IFO alignment
|
IFO aligned to maximize flashings, except for GRY and LO-AS.
What we did: |
|
Thu May 26 19:55:43 2022, yuta, Configuration, BHD, Oplevs centered, BHD DCPDs are now online
|
[Paco, Yuta]
We have aligned the IFO (except for LO-AS and GRY), and centered all the oplevs.
We have also restored Gautam's in-air BHD DCPD setup and placed it to ITMY table. |
|
Fri May 27 17:45:53 2022, yuta, Configuration, BHD, BHD camera installed, GRY aligned
|
[JC, Paco, Yuta]
After the IFO recovery (elog 40m/16881), we installed an analog camera for BHD fringe |
|
Thu Jun 2 20:05:37 2022, yuta, Configuration, PSL, IMC input power recovered to 1W, some alignment works
|
[Paco, Yuta]
We have increased the output power from the PSL table to 951 mW (it was 96.7 mW). |
|
Fri Jun 3 12:13:58 2022, Paco, Configuration, CDS, Fix RFM channels
|
[Paco, Yuta]
We tried fixing the issue of LSC_TRY and LSC_TRX channels not working. We first did some investigation, and just like previously
reported by Chris, narrowed down the issue to the RFM channels coming from c1iscex/c1iscey. |
|
Fri Jun 3 15:22:51 2022, yuta, Update, LSC, Both arms locked with POY/POX, IR beam centered on TMs with ASS
|
[JC, Paco, Yuta]
We locked both Y and X arms with POY11 and POX11. |
|
Fri Jun 3 17:42:50 2022, yuta, Update, LSC, MICH locks with AS55_Q
|
AS path at AP table as re-aligned and confirmed that MICH can be locked with AS55 Q.
What we did: |
|
Sun Jun 5 19:46:40 2022, Paco, Update, LSC, Fixed IMC Trans sum issue
|
[Paco]
Fixed the issue below:
|
|
Mon Jun 6 13:35:11 2022, Paco, Update, LSC, First calibrated spectra of MICH at AS55 Q
|
[Paco, Yuta]
On the topic of high AS55_Q RFPD offset, it seems it stems from a small residual offset on top of the 42 dB whitening filter gain (previously
3 dB). We verified this by looking in the past using dtt and seeing an offset of ~ 100 counts, which are consistent with the hotfix. We reverted the whitening |
|
Fri Jun 17 16:22:21 2022, yuta, Update, LSC, Actuator calibration of BS. ITMX, ITMY, updated MICH displacement spectra from c1cal 6x
|
Following what we have done in 2013 (40m/8242), actuator calibration was done using MICH.
AS55_Q in MICH : 9.74e8 counts/m
BS : 26.08e-9 /f^2 m/counts |
|
Thu Jul 7 18:18:19 2022, yuta, Update, LSC, Actuator calibration of ETMX and ETMX
|
(This is a complete restore of elog 40m/16970 from July 5, 2022
at 14:34)
ETMX and ETMY actuators were calibrated using single arm lock by taking the actuation efficiency ratio between ITMs. Below is the result. |
|
Thu Jul 7 18:22:12 2022, yuta, Update, LSC, Actuator calibration of MC2 using Yarm
|
(This is also a restore of elog 40m/16971 from Jul 5, 2022 at
17:36)
MC2 actuator calibration was also done using Yarm in the same way as we did in 40m/16970 (now |
|
Fri Jul 8 16:18:35 2022, rana, Update, LSC, Actuator calibration of MC2 using Yarm
|
although I know that Yuta knows this, I will just put this here to be clear: the NNN/f^2 calibration is only accurate abouve the pendulum POS eiegenfrequency,
so when we estimate the DC part (in diaggui, for example), we have to assume that we have a pendulum with f = 1 Hz and Q ~5, to get the value of DC gain
to put into the diaggui Gain field in the calibration tab. |
|
Mon Jul 18 17:07:12 2022, yuta, Update, LSC, x4.12 added to ETMX coil outputs to balance with ETMY
|
To balance the actuation on ETMX and ETMY, x4.12 was aded to C1:SUS-ETMX_(UL|UR|LR|LL|SD)COIL FM1.
OSEM damping filter gains, oplev loop gains, and alignment offsets were divided by this factor.
C1:LSC-ETMX_GAIN is now 1. |
|
Thu Jun 16 18:23:15 2022, Paco, Configuration, BHD, Recovering LO beam in BHD DCPDs
|
[Paco, Yuta]
We recovered the LO beam on the BHD port. To do this, we first tried reverting to a previously "good" alignment but couldn't see
LO beam hit the sensor. Then we checked the ITMY table and couldn't see LO beam either, even though the AS beam was coming out fine. The misalignment |
|
Tue Jun 21 14:17:50 2022, yuta, Configuration, BHD, BHD DCPDs re-routed to c1sus2
|
After discussing with Anchal, we decided to route BHD related PD signals directly to ADC of c1sus2, which handles our new suspensions including
LO1, LO2, AS1, AS4, so that we can control them directly.
BHD related PD signals will be sent to c1lsc for DARM control. |
|
Tue Jul 19 16:00:34 2022, yuta, Configuration, BHD, Fast channels for BHD DCPDs now available in c1lsc but not in c1hpc
|
[Paco, Anchal-remote-support, Yuta]
We added fast channels to BHD DC PDs.
C1:LSC-DCPD_(A|B)_IN1 are now available, but |
|
Thu Jul 21 21:50:47 2022, Tega, Configuration, BHD, c1sus2 IPC update
|
IPC issue still unresolved.
Updated shared memory tag so that 'SUS' -> 'SU2' in c1hpc, c1bac and c1su2. Removed obsolete 'HPC/BAC-SUS' references
from IPC file, C1.ipc. Restarted the FE models but the c1sus2 machine froze, so I did a manual reboot. This brought down the vertex machines---which |
|
Fri Jul 22 15:05:26 2022, Tega, Configuration, BHD, c1sus2 shared memory and ADC fix
|
[Tega, Yuta]
We were able to fix the shared memory issue by updating the receiver model name from ''SUS' to 'SU2' and the ADC zero issue
by including both ADC0 and ADC1 in the c1hpc and c1bac models as well as removing the grounding of the unused ADC channels (including chn#16 and chn#17 |
|
Fri Jul 22 17:46:10 2022, yuta, Configuration, BHD, c1sus2 watchdog update and DCPD ERR channels
|
[Tega, Yuta]
We have added C1:HPC-DCPD_A_ERR and C1:HPC-DCPD_B_ERR testpoints, which can be used as A+B, A-B etc. |
|
Mon Jul 25 17:58:10 2022, Tega, Configuration, BHD, c1sus2 IPC dolphin issue update
|
From the 40m wiki, I was able to use the instructions here
to map out what to do to get the IPC issue resolved. Here is a summary of my findings.
I updated the /etc/dis/dishost.conf file on the frame builder machine to include the c1sus2 machine which runs the sender model, c1hpc, see below. |
|
Mon Aug 1 18:42:39 2022, Tega, Configuration, BHD, c1sus2 IPC dolphin issue update
|
[Yuta, Tega]
We decided to give the dolphin debugging another go. Firstly, we noticed that c1sus2 was no longer recogonising the dolphin card, which can be
checked using |
|
Tue Aug 2 17:25:18 2022, Tega, Configuration, BHD, c1sus2 dolphin IPC issue solved
|
[Yuta, Tega, Chris]
We did it! |
|
Mon Jul 25 18:09:41 2022, Tega, Configuration, BHD, BHD Homodyne Phase control MEDM screen
|
[Paco, Tega, Yuta]
Today, we made a custom MEDM screen for the BHD Homodyne Phase Control, which is basically an overview of the c1hpc model. See Attachments
1 & 2 for details. |
|
Wed Aug 3 15:01:13 2022, Koji, Update, General, Borrowed Dsub cables
|
Borrowed DSUB cables for Juan's SURF project
- 2x D25F-M cables (~6ft?)
- 2x D2100103 ReducerCables |
|
Fri Jul 29 22:37:54 2022, Koji, Update, IOO, WFS investigation
|
I wanted to check what's wrong with the WFS.
I played with MC2 misalignment to check the error signals.
MC2 pitch and yaw misalignment optically produce a vertical translation and horizontal rotation of the cavity axis at the waist, |
|
Tue Aug 2 01:10:26 2022, Koji, Update, IOO, WFS investigation
|
Continued to work on the WFS repair
Demod phase adjustment:
- Use the PDH signal to adjust the demodulation phase to have uniform signals between the segments. |
|
Thu Aug 4 21:58:18 2022, Koji, Update, IOO, WFS investigation
|
OK... It seems that all the 6 dof of the IMC WFS servo loops were closed with some condition...
- Measured the transfer functions from ASCPIT/YAW_EXC of each suspensions to WFS segs.
- FInd the proper input matrix for PIT and YAW for WFS1 and WFS2 |
|
Thu Aug 4 22:14:20 2022, Koji, Update, IOO, WFS investigation
|
Sensing matrix measurement
MCx_ASCyyy_EXC was shaken with the amplitude of 3000 cnt. Measure the transfer functions to each segment of the WFS I&Q demod outputs.
- Pitch excitations consistently indicated WFS1 SEG2&3 / SEG1&4, and WFS2 SEG 1&2 / SEG 3&4 are |
|
Thu Aug 4 22:14:38 2022, Koji, Update, IOO, WFS investigation
|
WFS/MCTRANS_QPD Power Spectra
Attachment 1: HEPA ON
WFS1/2 PIT/YAW Spectra are stabilized below 1Hz (0.1Hz for WFS1P) |
|
Thu Aug 4 22:32:31 2022, Koji, Update, IOO, Upon leaving the lab (WFS investigation)
|
Upon leaving the lab:
- HEPA is ON at the original speed (i.e. same speed at 5PM today)
- WFS servo is ON, partly because we want to see how stable it is. It is not handled with the autolocker right now. |
|
Fri Aug 5 12:42:12 2022, Koji, Update, IOO, IMC WFS: Overnight observation
|
The IMC lock survived overnight and the WFS servo loops kept it aligned. The IMC was unlocked in the morning.
The left 6 plots are the WFS servo outputs and the right most two plot show the transmission and reflection of the IMC.
If the WFS is making the lock unstable under high seismic conditions, please turn the loops off. |
|
Fri Jul 29 20:21:11 2022, Koji, Update, PSL, FSSSlow/MCAutolocker issue (docker)
|
MCAutolocker/FSSSlow are not properly documented and not properly working.
Tidy up the script and documentation, or bring it back to megatron
I was aware that the FSSSlow was misbehaving since the shutdown upon the July power outage. |
|
Sat Jul 30 10:38:12 2022, Anchal, Update, PSL, FSSSlow/MCAutolocker issue (docker)
|
The FSSSlow script was not properly documented and it was not working, so I had to use one that I knew worked from CTN. This scripts lives in
/opt/rtcds/caltech/c1/Git/40m/scripts/PSL/FSS/PIDLocker.py
and uses a configuration file |
|
Sat Jul 30 12:48:18 2022, Koji, Update, PSL, FSSSlow/MCAutolocker issue (docker)
|
> it only starts working when C1:IOO-MC_LOCK is 1 and C1:PSL-FSS_SLOWLOOP is 1.
- OK. Your new MCAutolocker does not reflect the lock status to C1:IOO-MC_LOCK. This causes FSS Slow to go crazy when the IMC is not locked.
Can you fix that? |
|
Thu Aug 4 11:28:22 2022, Anchal, Update, PSL, FSSSlow/MCAutolocker issue (docker)
|
Added C1:IOO-MC_LOCK to ALConfigMC.yml which solved
the isse with FSS Slow. We should tune the FSS Slow Servo PID coefficients for a better performance.
the C1PSL_SLOW.adl screen is not obsolete. It can be used to change the PID coefficients, engage/disengage the PID loop, monitor the PID script |
|
Mon Aug 8 14:47:10 2022, rana, Update, PSL, FSSSlow/MCAutolocker issue (docker)
|
can't we just go back to the old python script that was working for many years, and tested? I imagine that as soon as someone besides you tries to
debug the docker setup, this is what will happen.
|
|
Wed Aug 10 15:33:59 2022, Cici, Update, General, Working Red Pitaya VNA
|
TL;DR: I am now able to inject a swept sine and measure a transfer function with python on my Red Pitaya! Attached is a Bode plot for a swept sine
from 1 - 30 MHz, going through a band pass filter of 9.5 - 11.5 MHz.
------------------------------------------------------------------------------------ |
|
Wed Aug 10 19:24:19 2022, rana, Update, General, Working Red Pitaya VNA
|
Boom!
|
|
Wed Aug 10 19:36:45 2022, Koji, Bureaucracy, General, Lab cleaning and discovery
|
During the cleaning today, we found many legacy lab items. Here are some policies what should be kept / what should be disposed
Dispose
VME crates and VME electronics as long as they are not in use
Eurocard SUS modules that are not in use.
Eurocard |
|
Wed Aug 10 20:30:54 2022, Tega, Summary, SUS, Characterisation of suspension damping 12x
|
[Yuta, Tega]
We diagnosed the suspension damping of the IMC/BHD/recycling optics by kicking the various degree of freedom (dof) and then tuning the gain so
that we get a residual Q of approx. 5 in the cases where this can be achieved. |
|
Wed May 20 20:10:34 2020, rana, John Z, Update, Computer Scripts / Programs, NDS2 server / conf updated - seems OK now
|
We noticed about a week ago that the NDS2 channel lists were not getting updated on megatron. JZ and I investigated; he was able to fix it all
up this afternoon by logging in and snooping around Megatron.
Please try it out and tell me about any problems in getting fresh data. |
|
Thu May 21 15:31:26 2020, gautam, Update, Computer Scripts / Programs, NDS2 service restarted
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The service had failed at 16:09 yesterday. I just restarted it and am now able to fetch data again.
Unrelated to this work: I restarted the httpd service on nodus a couple of times this afternoon while experimenting with the summary pages.
Quote:
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Fri May 22 10:37:41 2020, rana, Update, Computer Scripts / Programs, NDS2 service restarted
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was dead again this morning - JZ notified
current restart instructions (after ssh to megatron):
cd /home/nds2mgr/nds2-megatron |
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Mon May 25 10:54:41 2020, rana, Update, Computer Scripts / Programs, NDS2 service restarted
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so far it has run through the weekend with no problems (except that there are huge log files as usual).
I have started to set up monit to run on megatron to watch this process. In principle this would send
us alerts when things break and also give a web interface to watch monit. I'm not sure how to do web port forwarding between megatron and nodus, so |
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Thu Aug 11 16:48:59 2022, rana, Update, Computer Scripts / Programs, NDS2 updates
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We had several problems with our NDS2 server configuration. It runs on megatron, but I think it may have had issues since perhaps not everyone was aware
of it running there.
channel lists were supposed to updated regularly, but the nds2_nightly script did not exist in the specified directory. I have moved |
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Thu Aug 11 17:15:33 2022, Cici, Update, General, Measuring AUX Laser UGF with Red Pitaya
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TL;DR: Have successfully measured the UGF of the AUX laser on my Red Pitaya! Attached is one of my data runs (pdf + txt file).
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Figured out how to get a rudimentary coherence (use scipy.signal.coherence to get Cxy = abs(Pxy)**2/(Pxx*Pyy), then find |
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Fri Aug 12 13:40:36 2022, JC, Update, General, Preparing for Shutdown on Saturday, Aug 13
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[Yehonathan, JC]
Our first step in preparing for the Shutdown was to center all the OpLevs. Next is to prepare the Vacuum System for the shutdown.
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Wed Aug 17 10:27:49 2022, Cici, Update, General, Locking X-arm AUX laser
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TL;DR: Got the x-arm aux laser locked again and took more data - my fit on my transfer functions need improvement and my new method for finding coherence
doesn't work so I went back to the first way! See attached file for an example of data runs with poor fits. First one has the questionable coherence
data, second one has more logical coherence. (ignore the dashed lines.) |
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Thu Aug 18 16:35:29 2022, Cici, Update, General, UGF linked to optical gain!
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TL;DR: When the laser has good lock, the OLTF moves up and the UGF moves over!
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Figured out with Paco yesterday that when the laser is locked but kind of weakly (mirrors on the optical table sliiightly out of alignment, for |
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Fri Jul 1 08:50:48 2022, yuta, Summary, LSC, FPMI with REFL/AS55 trial
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[Anchal, Paco, Yuta]
We tried to lock FPMI with REFL55 and AS55 this week, but no success yet.
FPMI locks with POX11, POY11 and ASDC for MICH stably, but handing over to 55's couldn't be done yet. |
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Thu Jul 14 00:10:08 2022, yuta, Summary, LSC, FPMI with REFL/AS55 trial continued
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[Paco, Koji, Yuta]
We managed to lock MICH using REFL55_Q by setting the demodulation phases and offsets right.
The following is the current FPMI locking configuration we achieved so far. |
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Fri Jul 15 19:13:22 2022, Paco, Summary, LSC, FPMI with REFL/AS55 demod phase adjust
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[Yuta, Paco]
We first zero the offsets in ASDC, AS55, REFL55, POX11, and POY11 when PSL shutter is closed.
After this, we checked the
offsets with only ITMX aligned. Some of RFPDs had ~2 counts of offsets, which indicate some RFAM of sidebands, but we decided not to tune Marconi frequencies |
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Fri Jul 15 22:36:04 2022, rana, Summary, LSC, FPMI with REFL/AS55 demod phase adjust
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Very nice!
DARM feedback should go to ETMY - ETMX, not just a single mirror: Differential ARM.
For it to work with 1 mirror the UGF of the CARM loop must be much larger than DARM UGF. But in our case, both have a UGF of ~150 Hz. |
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Mon Jul 18 16:39:07 2022, Paco, Summary, LSC, FPMI locking procedure using REFL55 and AS55
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[Yuta, Paco]
In summary, we locked FPMI using REFL55_I, REFL55_Q, and AS55_Q. The key to success was to mix POX11_I and POY11_I in the right way
to emulate CARM/DARM, and to find out the correct demodulation phase for AS55. |
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Mon Jul 18 21:41:42 2022, Anchal, Summary, LSC, FPMI locking procedure using REFL55 and AS55
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Now that you have found a working configuration, I suggest we update CARM and DARM filter banks so that they are used in locking those degrees of freedom
instead of repurposing XARM/YARM banks. It would be bit easier to understand and leaves room for future changes for one configuration while keeping single
arm lock configurations untouched. |
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Tue Aug 9 19:54:31 2022, yuta, Summary, LSC, FPMI locking tonight
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[Tega, Anchal, Yuta]
We resored FPMI locking settings. Below is the summary of locking configurations tonight. |
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Thu Aug 18 14:49:35 2022, Yehonathan, Summary, LSC, FPMI Sensitivity
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{Yuta, Yehonathan}
We wrote a notebook found on Git/40m/measurements/LSC/FPMI/NoiseBudget/FPMISensitivity.ipynb for calculating the MICH, DARM (currently XARM),
CARM (currently YARM) sensitivities in the FPMI lock which can be run daily. |
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Thu Aug 18 18:10:49 2022, Koji, Summary, LSC, FPMI Sensitivity
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The overlapping plot of the calibrated error and control signals gives you an approximately good estimation of the freerun fluctuation,
particularly when the open-loop gain G is much larger or much smaller than the unity.
However, when the G is close to the unity, they are both affected by "servo bump" and both signals do not represent the |
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Wed Aug 17 01:18:54 2022, Koji, Update, General, Notice: SURF SUS test setup blocking the lab way
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Juan and I built an analog setup to measure some transfer functions of the MOS suspension. The setup is blocking the lab way around the PD test bench.
Excuse us for the inconvenience. It will be removed/cleared by the end of the week. |
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Fri Aug 19 15:20:14 2022, Koji, Update, General, Notice: SURF SUS test setup blocking the lab way
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| The setup was (at least partially) cleared. |
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Fri Aug 19 15:36:10 2022, Koji, Update, General, SR785 C21593 CHA+ BNC broken
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When Juan and I were working on the suspension measurement, I found that CHA didn't settle down well.
I inspected and found that CHA's + input seemed broken and physically flaky. For Juan's measurements, I plugged + channels (for CHA/B)
and used - channels as an input. This seemed work but I wasn't sure the SR functioned as expected in terms of the noise level. |
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Wed Aug 17 07:35:48 2022, yuta, Bureaucracy, General, My wish list for IFO commissioning
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FPMI related
- Better suspension damping HIGH
- Investigate ITMX input matrix diagonalization (40m/16931) |
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Fri Aug 19 14:46:32 2022, Anchal, Update, SUS, Open loop transfer function measurements for local damping loops of BHD optics
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[Anchal, Tega]
As a first step to characterize all the local damping loops, we ran an open loop transfer function measurement test for all BHD optics, taking
transfer function using band-limited (0.3 Hz to 10 Hz) gaussian noise injection at error points in different degrees of freedom. Plots are in the git repo. |
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Sat Aug 20 20:26:10 2022, Anchal, Update, SUS, Open loop transfer function measurements for local damping loops of Core optics
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I made measurements of old optics OLTF today. I have reduced the file sizes of the plots and data now. It is interesting that it is allowed to read 9
channels simultaneously from c1mcs or c1sus models, even together. The situation with c1su2 is a bit unclear. I was earlier able to take measurements of
6 channels at once from c1su2 but not I can't read more than 1 channel simultaneously. This suggests that the limit is dictated by how much a single |
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Mon Aug 22 14:36:49 2022, rana, Update, SUS, Open loop transfer function measurements for local damping loops of Core optics
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for damping and OL loops, we typically don't measure the TF like this because it takes forever and we don't need that detailed info for anything.
Just use the step responses in the way we discussed at the meeting 2 weeks ago. There's multiple elog entries from me and others illustrating this.
The measurement time is then only ~30 sec per optic, and you also get the cross-coupling for free. No need for test-point channels and overloading, just |
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Tue Aug 23 14:59:15 2022, JC, Update, Tools, New Toolbox at Y-End
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A new tool box has been placed at the Y-end! Each drawer has its label so PLEASE put the tools back in their correct
location. In addition to this, Each tool has its assigned tool box, so PLEASE RETURN all tools to their designated
tool box. The tools can be distinguished by a writing or heat shrink which corresponds to the color of the tool chest or location. Photo #2 is an example |
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Wed Aug 24 10:49:43 2022, Cici, Update, General, Measuring DFD output/X-arm laser PZT TF with Moku
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We measured the TF of the X-arm laser PZT using the Moku so we can begin fitting to that data and hopefully creating a digital filter to cancel out PZT
resonances.
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Wed Aug 24 12:02:24 2022, Paco, Update, SUS, ITMX SUS is sus UL glitches?
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[Yehonathan, Paco]
This morning, while attempting to align the IFO to continue with noise-budgeting, we noted the XARM lock was not stable and showed glitches in
the C1:LSC-TRX_OUT (arm cavity transmission). Inspecting the SUS screens, we found the ULSEN rms ~ 6 times higher than the other coils so we opened an |
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Wed Aug 24 16:37:52 2022, Cici, Update, General, More DFD/AUX PZT resonance measurements
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Some more measurements of the PZT resonances (now zoomed in!) I'm adjusting parameters on our model to try and fit to it by hand a bit, definitely
still needs improvements but not bad for a 2-pole 2-zero fit for now. I don't have a way to get coherence data from the moku yet but I've got a
variety of measurements and will hopefully use the standard deviation to try and find a good error prediction... |
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Thu Aug 25 15:24:06 2022, Paco, HowTo, Electronics, RFSoC 2x2 board -- fandango
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[Paco, Chris Stoughton, Leo -- remote]
This morning Chris came over to the 40m lab to help us get the RFSoC board going. After checking out our setup, we decided to do a very basic
series of checks to see if we can at least get the ADCs to run coherently (independent of the DACs). For this I borrowed the Marconi 2023B from inside |
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Thu Aug 25 16:39:31 2022, Cici, Update, General, I have learned the absolute basics of github
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| I have now added code/data to my github repository. (it's the little victories) |
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Fri Aug 26 12:46:07 2022, Cici, Update, General, Progress on fitting PZT resonances
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Here is an update of how fitting the resonances is going - I've been modifying parameters by hand and seeing the effect on the fit. Still a work
in progress. Magnitude is fitting pretty well, phase is very confusing. Attempted vectfit again but I can't constrain the number of poles and zeros
with the code I have and I still get a nonsensical output with 20 poles and 20 zeros. Here is a plot with my fit so far, and a zip file with my moku data |
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Mon Aug 29 13:33:09 2022, JC, Update, General, Lab Cleanup
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The machine shop looked a mess this morning, so I cleaned it up. All power tools are now placed in the drawers in the machine shop. Let me
know if there are any questions of where anything here is placed. |
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Mon Aug 29 18:25:12 2022, Cici, Update, General, Taking finer measurements of the actuator transfer function
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Took finer measurements of the x-arm aux laser actuator tranfer function (10 kHz - 1 MHz, 1024 pts/decade) using the Moku.
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I took finer measurements using the moku by splitting the measurement into 4 sections (10 - 32 (~10^4.5) kHz, 32 - 100 kHz, 100 - 320 kHz, 320 |
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Wed Aug 31 11:39:48 2022, Yehonathan, Update, LSC, Updated XARM noise budget
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{Radhika, Paco, Yehonathan}
For educational purposes we update the XARM noise budget and add the POX11 calibrated dark noise contribution (attachment). |
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Wed Aug 31 12:57:07 2022, rana, Summary, ALS, control of ALS beat freq from command line -easy
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The PZT sweeps that we've been making to characterize the ALS-X laser should probably be discarded - the DFD was not setup correctly for this during
the past few months.
Since the DFD only had a peak-peak range of ~5 MHz, whenever the beat frequency drifts out of the linear range (~2-3 MHz), the data would have |