Thu May 31 10:19:42 2018, gautam, Update, SUS, MC3 glitchy
|
Seems like as a result of my recent poking around at 1X6, MC3 is more glitchy than usual (I've noticed that the IMC lock duty cycle seems degraded
since Tuesday). I'll try the usual cable squishing voodo.
gautam 8.15pm: Glitches persisted despite my usual cable squishing. I've left PSL shutter closed and MC watchdog |
Thu May 31 15:36:59 2018, gautam, Update, General, New camera channels
|
Jon informed me that there are some EPICS channels that JoeB's camera server code looks for that don't exist. I thought Jigyasa and I had added
everything last year but turned out not to be the case. I followed my instructions from here,
did the trick. While cleaning up, I also re-named the "*MC1" channels to "*ETMX", since that's where the camera now resides. New |
Thu May 31 15:48:16 2018, Kira, Update, PEM, running PID script with seismometer
|
I have attached the result of running the PID script on the seismometer with the can on. The daily fluctuations are no more than 0.07 degrees off from
the setpoint of 39 degrees. Not really sure what happened in the past day to cause the strange behavior. It seems to have returned back to normal today. |
Thu May 31 17:47:12 2018, Koji, Update, Computers, megatron process cleaning up
|
megatron had full of zombie medm processes due to some of the screenshot scripts.
I also found that apache2 is running on megatron without any configuration. I just disable it by
sudo update- |
Thu May 31 19:51:06 2018, Koji, Update, General, WiFi router firmware update / rebooting
|
The model of our martian wifi router (NETGEAR R6400) was found in the FBI router list to be rebooted asociated with the malware "VPNFilter"
issue.
I checked the attached devices and found bunch of (legit) devices blocked to access the wifi router. This is not an immediate problem as most |
Thu May 31 23:12:17 2018, gautam, Update, LSC, DRMI locking attempt
|
Summary:
I wanted to recover the DRMI locking. Among other things, Jon mentioned that his mode spectroscopy can be done in the DRMI config. But I was
foiled last night by a rogue waveplate in the AS beampath, and today evening, I noticed the resurfacing of this |
Fri Jun 1 01:22:50 2018, gautam, Update, LSC, DRMI locking restored
|
As it happened last time, the problem apparently fixed itself - somehow the act of me disconnecting the cables and reconnecting them seems to solve the
problem, need to think about this.
Anyway, DRMI was locked a few times tonight |
Fri Jun 1 19:25:11 2018, pooja, Update, Cameras, Synchronizing video data with the applied motion to the mirror
|
Aim: To synchronize data from the captured video and the signal applied to ETMX
In order to correlate the intensity fluctuations of the scattered light with the motion of the test mass, we are planning to use the technique
of neural network. For this, we need a synchronised video of scattered light with the signal applied to the test mass. Gautam helped me capture 60sec video |
Sun Jun 3 22:48:59 2018, johannes, Update, PSL, aux laser replacement
|
I brought the NPRO from the Crackle experiment over to the 40m Lab and set it up on the PSL table to replace the slowly dying AUX laser. I also brought
along a Faraday isolator, broadband EOM, and an ISOMET AOM with driver electronics from the optics storage in the Crackle Lab.
This laser is a much newer model, made in 2008, and still has all its mojo, but we should probably keep up the practice of turning it off when |
Mon Jun 4 02:52:52 2018, johannes, Update, PSL, aux laser replacement
|
> While the laser output is going strong, the controller displays a power output of only 10 mW, which makes me think that the power monitoring PD
is busted.
NPRO internal power monitor often shows smaller value than the actual due to a broken PD or misalignment. I don't think we need to fix it. |
Mon Jun 4 11:00:37 2018, gautam, Update, PSL, aux laser replacement
|
Quote:
I couldn't locate an appropriate heat sink for the driver, which is still in factory condiction, but since
the PSL AOM also runs on 80MHz I used that one instead. |
Mon Jun 4 11:34:05 2018, Jon Richardson, Update, Cameras, Update on GigE Cameras
|
I spent a day trying to modify Joe B.'s LLO camera client-server code without ultimate success. His codes now runs without throwing any
errors, but something inside the black-box handoff of his camera source code to gstreamer appears to be SILENTLY FAILING. Gautam suggested a call
with Joe B., which I think is worth a try. |
Mon Jun 4 19:41:01 2018, keerthana, Update, , Finesse code for cavity scan 
|
The cavity scan data obtained from the Finesse simulation is attached here. Fig1 indicates the cavity scan data in the absence of induced misalignment.
In that case only the fundemental mode is resonating. But when a misalignment is induced, higher order modes are also present as seen in Fig2. This is
in the absence of surface figure error in the mirrors. Now I am trying to provide perturbations to the mirror surface in the form of zernike polynomials |
Tue Jun 5 02:06:59 2018, gautam, Update, PSL, aux laser first (NULL) results
|
[johannes, gautam]
Johannes aligned the single bounce off the ITM into the AUX fiber on the AS table, and also the AUX beam into the fiber on the PSL table.
Mode
matching isn't spectaular anywhere in this chain.
But we have 2.6mW of light going into the SRM with the AOM deflection into the 1st order |
Tue Jun 5 20:31:42 2018, rana, Update, Cameras, Update on GigE Cameras
|
Aha! Video is back!
I think it would be good to add a flag whereby the video can be saved to disk in some uncompressed video format (ogg, avi, ?) instead of displayed
to a matplotlib window. We could then use the default to just display video, but use the save-to-disk flag to grab a few minutes of video for image processing. |
Wed Jun 6 10:02:52 2018, Steve, Update, VAC, RGA scan  
|
|
Wed Jun 6 10:44:52 2018, gautam, Update, VAC, Annulus pressure channels added to frames
|
[steve, gautam]
We added the following channels to C0EDCU.ini and restarted the daqd processes. Channels seem to have been added successfully, we will check
trend writing later today. Motivation is to have a long term record of annulus pressure (even though we are not currently pumping on the annulus). |
Wed Jun 6 14:36:15 2018, gautam, Update, LSC, TRX clipping
|
For some time now, I've been puzzled by the unreliability of the ASS_X dither alignment servo. Leaving the servo on, TRX often begins to decay to
a lower value, and even after freezing the dither at the maximum TRX values, I can manually align the mirrors to increase TRX. We have suspected some kind
of clipping in the TRX path that is responsible for this behaviour. Today I decided to investigate this a bit further. To have the arm locked and to inspect |
Wed Jun 6 14:50:25 2018, gautam, Update, General, LSC triggering
|
I though that the "C1LSC_TRIG_MTRX" MEDM screen completely controls the triggring of LSC signals. But today while trying to trigger the X-arm
locking servo on AS110 instead of TRX, I found some strange behaviour. Summary of important points:
Even though the servo was supposed to be triggered on AS110, the act of me blocking the beam on the EX table destroyed the lock. I verified |
Wed Jun 6 15:12:29 2018, Kira, Update, PEM, parts from lab  
|
Got this 1U box from the Y arm that we could potentially use (attachment 1). It doesn't have handles on the front but I guess we could attach them
if necessary. Attachment 2 is a switch that could be used instead of a light up switch, but now we need to add LEDs on the front panel that indicate that
the switch is functional. Attachment 3 is a terminal block that we can use to attach the 16 gage wire to since it is thick and attaching it directly to |
Thu Jun 7 10:26:36 2018, keerthana, Update, PSL, observing the resonance signal corresponding to the injected frequency. 
|
(Johannes, Koji, Keerthana)
The PLL loop ensures that the frequency difference between the PSL laser and the AUX laser is equal to the frequency we provide to the Local
Oscillator (LO) with the help of a Marconi. Only a small pick off part of both the AUX and PSL lasers are going to the PLL loop. The other part of both |
Thu Jun 7 12:20:53 2018, gautam, Update, CDS, slow machine bootfest
|
FSS slow wasn't running so PSL PZT voltage was swinging around a lot. Reason was that was c1psl unresponsive. I keyed the crate, now it's okay. Now ITMX is stuck - Johannes just told be about an un-elogged |
Thu Jun 7 14:35:26 2018, keerthana, Update, elog, Table- useful for doing the scanning.
|
I think this table will help us to fix the scanning range of the Marconi frequency. This will also help in predicting the position of the resonance peak
corresponding to the injected frequency.
fdiff = fm ±80 |
Thu Jun 7 16:15:03 2018, gautam, Update, LSC, TRX clipping
|
I opted for the quickest fix - I raised the height of the offending steering mirror using a 0.25" shim. In the long term, we can get a taller post
machined. After raising the mirror height, I then checked the DC centering of the spot on the DC PD using a scope.
Looking at the performance of the X arm ASS, I no longer see the strange oscillatory behaviour I described in my previous post |
Thu Jun 7 20:19:53 2018, pooja, Update, ,
|
Just to inform, I'm working in optimus to develop python code to train the neural network since it requires a lot of memory. |
Thu Jun 7 20:21:15 2018, Koji, Update, Computer Scripts / Programs, /cvs/cds Backup in danger
|
Local backup on chiara
seems not working since Nov 19, 2017.
/opt/rtcds/caltech/c1/scripts/backup/localbackup.log |
Thu Jun 7 22:36:09 2018, not keerthana, Update, PSL, observing the resonance signal corresponding to the injected frequency.
|
I worked a bit on the PSL table today |
Fri Jun 8 00:36:54 2018, gautam, Update, PSL, observing the resonance signal corresponding to the injected frequency.
|
It isn't clear to me in the drawing where the Agilent is during this measurement. Over 40m of cabling, the loss of
signal can be a few dB, and considering we don't have a whole lot of signal in the first place, it may be better to send the stronger RF
signal (i.e. Marconi pickoff) over the long cable rather than the weak beat signal from the Transmission photodiode. |
Fri Jun 8 01:08:22 2018, johannes, Update, PSL, First light of AUX at YEND  
|
Among the things that we hadn't taken care of yesterday before beginning to look for transmission signals were the polarization of the AUX beam on
the AS table and optimizing the PLL feedback. The AUX beam is s-polarized on the PSL table (choice due to availablility of mirrors), and I added a half
waveplate in front of the fiber to match it's axes. I placed another half-waveplate at the fiber output and send the reflection port of a PBS cube |
Fri Jun 8 01:58:56 2018, gautam, Update, LSC, DRMI locking attempt again
|
Given the various changes to the IFO config since last Thursday when I was last able to lock the DRMI, I wanted to try once again tonight. However, I
had no success. By my judgement, the alignment is fine as judged by looking at mode flashes on the cameras. However, despite following the usual alignment
procedures, I did not get a single lock in tonight. |
Fri Jun 8 14:40:55 2018, c1lsc, Update, CDS, i am dead
|
|
Fri Jun 8 20:15:08 2018, gautam, Update, CDS, Reboot script
|
Unfortunately, this has happened (and seems like it will happen) enough times that I set up a script for rebooting the machine in a controlled way, hopefully
it will negate the need to repeatedly go into the VEA and hard-reboot the machines. Script lives at /opt/rtcds/caltech/c1/scripts/cds/rebootC1LSC.sh. SVN committed. |
Sun Jun 10 03:46:38 2018, Koji, Update, IOO, WFS HEAD SW confusion
|
I was checking on the slow machine channels and found something I could not understand.
On the IOO WFS HEAD screen, there are two sets of 4 switches (magenta rectangles in Attachment 1) labeled 2/4/8/16dB.
But as far as I could confirm with the WFS demod (D980233) and WFS head (D980012) drawings, they are the gain |
Sun Jun 10 15:04:33 2018, pooja, Update, Cameras, Developing neural network
|
Aim: To develop a neural network in order to correlate the intensity fluctuations in the scattered light to the angular motion of the test mass. A block
diagram of the technique employed is given in Attachment 1.
I have used Keras to implement supervised learning using neural network (NN). Initially I had developed a python code that converts a video (59 |
Mon Jun 11 11:45:13 2018, keerthana , Update, elog, Comparison of the analytical and finesse values of TMS and FSR.
|
Quantity
Analytical Value
Finesse Value
Percentage
Error
Free Spectral range (FSR)
3.893408 MHz
|
Mon Jun 11 13:55:33 2018, keerthana, Update, General, Project Updates
|
As of now, I have made the codes needed to sweep the marconi frequency for taking the cavity scan data, the photo diode at the y-end is conected to the
spectrum analyser already and I also have the finesse simulation of the Ideal Fabry-perot cavity. By seeing my last elog entry, Gautam suggested me that
I need to take a different approach for estimating the FSR and TMS value from the Finesse graph. That is, by using least square fit models. Now I am trying |
Mon Jun 11 17:18:39 2018, pooja, Update, Cameras, CCD calibration 
|
Aim: To calibrate CCD of GigE using LED1050E.
The following table shows some of the specifications for LED1050E as given in Thorlabs datasheet.
Specifications
|
Mon Jun 11 18:10:51 2018, Koji , Update, elog, Comparison of the analytical and finesse values of TMS and FSR.
|
Hmm? What is the definition of the percentage error? I don't obtain these numbers from the given values.
And how was the finesse value obtained from the simulation result? Then what is the frequency resolution used in Finesse simulation? |
Mon Jun 11 18:49:06 2018, gautam, Update, CDS, c1lsc dead again
|
Why is this happening so frequently now? Last few lines of error log:
[
575.099793] c1oaf: DAQ EPICS: Int = 199 Flt = 706 Filters = 9878 Total = 10783 Fast = 113 |
Mon Jun 11 19:16:49 2018, keerthana, Update, elog, Comparison of the analytical and finesse values of TMS and FSR.
|
The percentage error which I found out =[(analytical value - finesse value)/analytical value]*100
But inorder to find the finesse value, I just used curser to get the central frequency of each peak and by substracting one from the other I
found TMS and FSR. |
Mon Jun 11 22:05:03 2018, Koji, Update, elog, Comparison of the analytical and finesse values of TMS and FSR.
|
> The percentage error which I found out =[(analytical value - finesse value)/analytical value]*100
Yes, I this does not give us 0.70%
(3.893408 - 3.8863685)/3.893408 *100 = 0.18% |
Mon Jun 11 22:18:18 2018, keerthana, Update, elog, Comparison of the analytical and finesse values of TMS and FSR.
|
Oopss !! I made a mistake while taking the values from my notes. Sorry.
Quote:
> The percentage error which I found out =[(analytical value - finesse value)/analytical value]*100 |
Mon Jun 11 22:46:24 2018, Koji, Update, IOO, WFS HEAD SW confusion 
|
The unfortunate discovery today was that the attenuator switches on the IMC WFS heads are actually assigned to individual segments, and they are active.
That means that we have been running the WFS with an uneven gain setting. The attached PDFs show that the signals with the attenuators on and off all at
the same time, while the WFS servo output was frozen. A more annoying feature is that when some of the attenuators are on, this does not lower the |
Mon Jun 11 23:22:53 2018, gautam, Update, CDS, EX wiring confusion
|
[Koji, gautam]
Per this elog, we don't need any AIOut channels or Oplev channels. However, the
latest wiring diagram I can find for the EX Acromag situation suggests that these channels are hooked up (physically). If this is true, there are 12 ADC |
Tue Jun 12 03:22:25 2018, gautam, Update, LSC, AUX laser shuttered
|
I worked a bit on recovering the DRMI locking again tonight. I decided to shutter the AUX laser on the PSL table at least until I figured out the correct
locking settings. As has become customary now, there was a cable in the AS beampath (leading from the AS55 DC monitor to nothing, through the enclosure
side panel, it is visible in Attachment #3 in this elog) which I only found after 30mins of |
Tue Jun 12 19:27:25 2018, pooja, Update, Cameras, CCD calibration
|
Today I made the led (1050nm) circuit inside a box as given in my previous elog. Steve drilled a 1mm hole in the box as an aperture for led light.
Resistance (R) used = 665 .
We connected a power supply and IR has been detected using the card. |
Wed Jun 13 01:02:40 2018, gautam, Update, LSC, Reliable and repeatable 1f DRMI locking
|
[koji, gautam]
With Koji's help, I got repeatable and reliable DRMI locking going again tonight - this is with the AS path optics for the spectroscopy measurement
in place, although the AUX laser remained shuttered tonight. Results + spectra tomorrow, but here's what I did: |
Wed Jun 13 11:17:40 2018, gautam, Update, LSC, PRCL loop shape anomaly
|
Attachment #1 shows the measured PRCL
loop shape. The blue line is meant to be the "expected" loop shape. While the measured loop shape tracks the expectation down to ~100 Hz, I cannot
explain the shape below it. I am also not sure what to make of the fact that there is high coherence down to 10 Hz fron IN2 to IN1, but no coherence between |
Wed Jun 13 11:59:03 2018, keerthana, Update, elog, command line enabled code for frequency scanning
|
I have modified the code for frequency scanning and have made it completely command line enabled. The code is written in python. It is saved in the name
"frequency_scanning_argparse.py". I have uploaded it to the Mode-Spectroscopy Github repository.
Inorder to use this code there are two ways. |
Wed Jun 13 12:21:09 2018, gautam, Update, ALS, PDFR laser checkout
|
I want to use the Fiber Coupled laser from the PDFR system to characterize the response of the fiber
coupled PDs we use in the BeatMouth.
The documentation is pretty good: for a first test, I did the following in this order: |