40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 303 of 341  Not logged in ELOG logo
ID Date Author Type Categoryup Subject
  11320   Fri May 22 12:09:57 2015 ranaUpdateSUSDampRestore script problem

I will move it back. We need to fix our scripts to not use any users/ libraries ever again.


PRM watchdog tripped, but the damprestore.py script wouldn't run. 

It turns out the script tries to import some ezca stuff from /users/yuta (angry), which had been moved to /users/OLD/yuta (crying). 

I've moved the yuta directory back to /users/ until I fix the damprestore script. 


  11339   Mon Jun 1 08:32:14 2015 SteveUpdateSUSPRM damping restored

Local earthquake 3.8 Mag tripped only PRM

Vac monitor is not communicating.

PSL HEPA turned on

Attachment 1: indio3.8Meq.png
  11349   Tue Jun 9 10:57:12 2015 SteveUpdateSUS BS oplev laser tuned

Lenses removed from oplev beam path at elog entry 11246


Attachment 1: 100dBStrend0425.png
Attachment 2: 18dBSdrift.png
  11476   Mon Aug 3 08:16:19 2015 SteveUpdateSUSETMX damping restored
Attachment 1: ETMXrestored.png
  11525   Mon Aug 24 14:05:47 2015 ericqUpdateSUSEricG Investigating L2A

This afternoon, I showed Eric Gustafson some of the basics of making swept sine measurements with DTT. We turned off the f2a filters and oplev damping on the BS and made a cursory measurement of the transfer function from position drive to the oplev signals. 

He will be in the lab periodically to continue this line of investigations. 

  11526   Mon Aug 24 16:10:07 2015 ericqUpdateSUSETMY Oplev laser power is falling

Today I noticed the box around the ETMY oplev sum flashing red, as it dipped below 1k. I don't recall seeing this recently, so I wanted to look up the history.

However, we've been having trouble with our minute (and longer) trend data, so I had to hack it out a bit... Here is the unfortunate result:

I think we can be fairly confident that this is not due to alignment drifts, we generally keep the QPD reasonably well centered. I also recentered it today, and the counts remained at ~1k. 

Details of the hack that got me this data:

I ended up looking at the BURT snapshots from every night at midnight, which report a number for ETMY_OL_SUM_OUT16, and making a text file with dates and values with the following BASH spaghetti:

find /opt/rtcds/caltech/c1/burt/autoburt/snapshots/2015 -wholename "*00*/*scy*" |xargs ack --nogroup "ETMY_OL_SUM_OUT16 1" |  sed -e 's/.*2015/2015/g' -e 's/\/c1.*\([0-9]\..*$\)/, \1/g' -e 's/\//-/g'  > ETMYsum.txt

This produces a file full of unsorted lines like: 2015-Aug-23-00:07, 1.106459228515625e+03

The python package pandas is good at parsing dates and automatically plotting time series: 

olsum = pandas.read_csv('ETMYsum.txt', index_col=0, parse_dates=True)
Attachment 1: ETMYsum_trend.pdf
  11527   Mon Aug 24 16:46:49 2015 ericqUpdateSUSETMY Oplev laser power is falling

Repeated for all optics, ETMY seems like the only one sharply dropping for now (PRM is all over the place and hard to gauge, since we often leave it partially- or mis-aligned):


Hacky bits:


find /opt/rtcds/caltech/c1/burt/autoburt/snapshots/2015 -wholename "*00:0*"
| xargs ack --nogroup "OL_SUM_OUT16 1"
| grep -v 'SUS-MC'
| sed -e 's/.*2015/2015/g' -e 's/\/c1.*C1:SUS-/, /g' -e 's/_OL.*\([0-9]\..*$\)/, \1/g' -e 's/\//-/g'
| sort | uniq > allOL.txt

qontrols@pianosa|~ > head allOL.txt 
2015-Apr-10-00:07, BS, 1.146766113281250e+03
2015-Apr-10-00:07, ETMX, 1.597261328125000e+04
2015-Apr-10-00:07, ETMY, 4.331762207031250e+03
2015-Apr-10-00:07, ITMX, 6.488521484375000e+03
2015-Apr-10-00:07, ITMY, 1.387590234375000e+04
2015-Apr-10-00:07, PRM, 8.352053833007812e+02
2015-Apr-10-00:07, SRM, 6.099560928344727e+01
2015-Apr-1-00:07, BS, 1.180478149414062e+03
2015-Apr-1-00:07, ETMX, 1.584842480468750e+04



olsum = pd.read_csv('allOL.txt',parse_dates=True, names=['Date','Optic','Sum'])
olsum['Date'] = pd.to_datetime(olsum['Date']) # Automatic parsing didn't work for some reason
olpivot = olsum.pivot(index='Date',columns='Optic',values='Sum')
Attachment 1: OLsum_trend.pdf
  11566   Thu Sep 3 08:53:55 2015 SteveUpdateSUSETMY Oplev laser power is falling

Rana, Steve

We investigated the ETMY oplev table set up and did not find a red herring.

Two 2 years  vs one day plot below.

ps: thanks  Q for fixing  DTT, the auto scaling is not working at sampling rate 10 min and 1 hr period?? surprise


Attachment 1: ETMYoplev2y.png
  11569   Thu Sep 3 19:52:24 2015 ranaSummarySUSSUS drift monitor

Since Andrey's SUS Drift mon screen back in 2007, we've had several versions which used different schemes and programming languages. Diego made an update back in January.

Today I added his stuff to the SVN since it was lost in the NFS disks somewhere. Its in SUS/DRIFT_MON/.

Since we've been updating our userapps directory recently to pull in the screens and scripts from the sites, we also got a copy of the Thomas Abbott drift mon stuff which is better (Diego actually removed the yellow/red functionality as part of the 'upgrade'), but more complicated. For now we have the old one. I updated the good values with all optics roughly aligned just a few minutes ago.

Attachment 1: 07.png
  11642   Fri Sep 25 11:08:33 2015 SteveUpdateSUSwire standoffs

Our last effort to change the existing Al-6061 wire standoffs was at April 2012

We requested sapphire and/or ruby materials with smaller R at the bottom of the  groove. Groove polishing was asked for.

Insaco Inc. quote 84740 as " best effort " NO POLISHING.  The groove cut to be with eximer laser.

Jeff Lewis as 9-12-2012:  the LIGO sapphire prisms grooves were NOT POLISHED  but Resonatics used the corner of a rasor blade to scrape off the

ablated material wich was redeposited in and around the grooves.

Attachment 1: wireStandOff_SOS.PDF
  11643   Fri Sep 25 14:52:08 2015 SteveUpdateSUSETMX is not drifting

We have talked about the drift of ETMX sus on the Wednesday meeting.

It has stopped moving on Jan 8, 2015 and it has been reasanable stable since than.


Attachment 1: ETMXstoppedDrifting.png
Attachment 2: 25daysArmsT.png
  11646   Fri Sep 25 19:06:13 2015 ranaUpdateSUSETMX IS drifting

I don't see any evidence of it getting more stable. It seems there was a big step in January, but the problem we were talking about - the suspension shifting when it gets a big kick - can't be proven to be gone or not by just looking at the trends. The real issue is whether or not it slips when we put in a large step in the LSC.


We have talked about the drift of ETMX sus on the Wednesday meeting.

It has stopped moving on Jan 8, 2015 and it has been reasanable stable since than.


  11667   Mon Oct 5 11:25:21 2015 ericqUpdateSUSETMY OL laser dead

Gautam alerted me that the Y arm looked like it was being dithered, even though the ASS was turned off. I found that the ETMY OL signals were garbage, leading to the servos flipping back and forth between their rails. 

We went out to the ETMY table, and found the HeNe laser to be emitting a paltry <0.5mW; the OL QPD could not register the puny beam incident on it.

Here is the last 30 days of OL_SUM:

Steve will replace the laser this afternoon. 

  11668   Mon Oct 5 16:41:22 2015 SteveUpdateSUSETMY OL laser replaced

This JDSU 1103P laser, sn P892324 lived for 2 years. It's power output is 0.05 mW now

It was replaced with brand new JDSU 1103P,  sn P919645, Mfg date 12/2014 with 2.75 mW output.

There is 0.14 mW  light returning to the qpd = 7,250 counts without AR 632 lenses

  11702   Tue Oct 20 15:51:44 2015 ericqUpdateSUSMC2 F2P tuned

Using a modified version of Hang's deMod_deCoup scripts, I tuned the MC2 coil output matrix to minimize the appearance of POS drive in the SUSPIT signal at 28Hz. Up until now, there was no F2P compensation. This reduced the force to pitch coupling at 28Hz by 8dByes

Old: POS -> 1 x UL, 1 x UR, 1 x LL, 1x LR

New: POS -> 1.1054 x UL, 1.1054 x UR, 0.8946 x LL, 0.8946 LR

I checked the MCL spectrum before and after this change with OAF on, this did not spoil the feedforward length subtraction in any noticible way. 

The script lives in userapps/release/isc/c1/scripts/decoup, but I've symlinked it to /opt/rtcds/caltech/c1/scripts/decoup.

The script modification I made had to do with how the I and Q data is collected. Before, it was sporadically probing the I and Q FM output monitor EPICS values; I changed it to use the avg function of cdsutils, which calculates the mean and std from the 16kHz data and have seen it improve results by 1dB or so. I've been in touch with Jenne to propagate this to the sites. 

  11711   Fri Oct 23 21:58:10 2015 ranaUpdateSUSMC2 F2P mis-tuned

The OSEMs cannot be used for coil balancing above ~10 Hz. The main coupling path from OSEM drive to sensor is not through the mirror motion, but instead direct electrical coupling of the drive wires to the sensing wires.sad

I put this in the elog every ~1-2 years since people keep trying it, but it keeps coming back like a zombie.crying

Better to use the MC angular sensors for L2A decoupling. Not perfect, but better than OSEMs. For the TMs we can use the OLs.

  11716   Tue Oct 27 03:46:26 2015 ericqUpdateSUSMC2 F2P mis-tuned

D'oh. Good point.

Reverted for now; I'm thinking about doing laser pointer->MC2 QPD...

  11724   Fri Oct 30 17:49:27 2015 SteveUpdateSUSETMX kicked up

The oplev and  the LSC are off.

Attachment 1: ETMXkicking.png
Attachment 2: ETMXkickedbyOpPerror.png
Attachment 3: ETMXstillKicking.png
Attachment 4: ETMXkickingCond.png
Attachment 5: 7hrsETMX-Y.png
  11727   Tue Nov 3 18:49:41 2015 gautamUpdateSUSETMX kicked up

I was trying to take a few more IR transmission scans with ALS when the ETMX got kicked again. I'm not sure how to fix this, so for the time being, I'm leaving the Oplev servo and the LSC turned off. The oplev spot looks really far off center especially in yaw, the yaw error is ~ -80.


The oplev and  the LSC are off.


  11729   Wed Nov 4 14:44:00 2015 ericqUpdateSUSETMX oplev servo disabled

I've turned the ETMX oplev servos off for the time being. (At the input side, so that no scripts will accidently turn it on).

Thus, only the local damping is being applied, let's see if we see any kicks...

  11733   Wed Nov 4 22:42:02 2015 ericqUpdateSUSETMX oplev servo disabled

During this time period, it looks like there was maybe one excursion. Here are the individual OSEM signals, which I think to be calibrated to microns. 

When I'm doing other things, I'm going to intentionally leave the watchdog tripped, and see if anything happens. 

  11744   Mon Nov 9 23:22:18 2015 ericqUpdateSUSETMX oplev servo disabled

During a ETMX kick that just occured, with only local damping on, the slow VMon channels didn't show any noticable change. 

  11752   Wed Nov 11 14:06:09 2015 ranaUpdateSUSETMX oplev servo disabled

How many volts does it take to pitch the ETM by 5 urad?

  11753   Wed Nov 11 22:11:15 2015 KojiUpdateSUSPSL/IOO maintenance, TM SUS check up


- Before any of the following work, I went to the PSL table and aligned the PMC. In fact, it has not been misaligned.


- It was claimed in the meeting today that the IMC had not been happy thesedays. I checked out what's happening.

- I found the IMC was still well aligned. Autolocker frequently stuck on a weak higher-order mode and couldn't recover TEM00 locking without help.

- I modified /opt/rtcds/caltech/c1/scripts/MC/mcdown for easier relocking on TEM00.

The MC_REFL_GAIN and MC_VCO_GAIN for relocking was set to be 27 and -3, in stead of 0 and 10, respectively.
This means that REFL_GAIN is not changed before and after the locking. Only VCO_GAIN is lowered for lock acquisition.
The corresponding lines in mcdown are excerpted here.

#set servo and boost gains for re-acquisition
#${ewrite} C1:IOO-MC_REFL_GAIN 0 &
${ewrite} C1:IOO-MC_REFL_GAIN 27 &
#${ewrite} C1:IOO-MC_VCO_GAIN 10 &
${ewrite} C1:IOO-MC_VCO_GAIN -3 &

We still have some chance of locking on higher-order modes. If I jiggle the VCO gain slider from -31 to 0, eventually I find TEM00.
I don't know how to do it in the script yet. For now, I increased tickle amplitude from 300 to 500.




- IMC was locked and aligned with the WFS. The WFS feedback offsets were offloaded to the alignment slider (via the MEDM button as usual).


- I wanted to use ASS. => The OL damping and ASC inputs are enabled for ETMX. The filter bank output of the ASS servos are all turned on.
- The arms were locked and aligned with ASS. The ASS servo offsets were offloaded to the ASC offset sliders (as usual).

- I found the X arm spot positionis moving slowly in pitch. I wanted to know what is causing this.

- Turned off all the OPLEV dampings for the four test masses.
- Took the power spectra of the OSEM output (e.g. C1:SUS-ITMX_LLSEN_OUT)

See attachment 1 (The DTT XML file can be found as /users/koji/151111/TM_SUS.xml )

- It seems that something is wrong with ITMX UL OSEM
  The signal level seems to be identical with the others. However, the noise level is huge. We need to check if the cable connection is OK.

- ITMY LL shows remarkably higher bounce mode although I can't tell if this is normal or not.

- The OPLEV dampings have been restored.

Attachment 1: TM_SUS.pdf
Attachment 2: TM_SUS_SD.pdf
  11755   Thu Nov 12 09:15:56 2015 SteveUpdateSUSITMX osems

The ITMX OSEMS are oscillating.

Attachment 1: ITMX.png
  11758   Thu Nov 12 10:47:17 2015 ericqUpdateSUSETMX oplev servo disabled

By looking at the oplev and Vmons before and after a step of 90 counts in SUS-ETMX_PIT_OFFSET, I observe:

  • UL: +1.53mV / urad
  • UR: -1.94mV / urad
  • LR: -1.54mV / urad
  • LL: +1.92mv / urad

The random error associated with these measurements is ~0.02mV

So, the ~7urad urad shift seen in my earlier post would mean a change of around 10mV in the Vmon signals, which isn't evident in the traces. So, this is possibly a piece of evidence in favor of a real mechanical shift, rather than an electronic glitch. 

  11760   Fri Nov 13 15:20:24 2015 SteveUpdateSUSOSEMs

Are they oscillating or not ?


The ITMX OSEMS are oscillating.

ETMX, ETMY and MC2 POS _biases are off. Why ?

The Epics MEDMs screens are going blank in  ~3-5 minutes reluctantly.

Attachment 1: OSEMs.png
Attachment 2: POSbiasOFF.png
  11770   Tue Nov 17 00:57:21 2015 ericqUpdateSUSITMX UL calmed?

After running dither alignment for all mirrors, all oplevs were recentered. (Except ETMY, since we did that earlier today.)

Looking at Koji's template for OSEM signals, the ITMX UL sensor noise floor seems more in line with the LL sensor, though there continues to be more noise than in other mirrors. 


Trending the sensor signals over the past 7 days, Koji's measurement looks to have been taken during a time when the UL sensor voltage had jumped down. Did someone squish the satellite box cable? I have not done so. 

I think that the step right at the end is due to a new POS offset of -2k counts, which I think Koji put into place earlier today. 

According to the wiki, the Vmax/2 values and the current values are: 



















Attachment 1: TM_nov17.pdf
  11774   Tue Nov 17 15:59:23 2015 ranaUpdateSUSITMX UL calmed?

Although this noise is bad, we have always had these kind of humps around the bounce mode. Our interpretation in the past was that this was due to poor alignment of the OSEM in the frame, leading to a large vertical to horizontal coupling. Once you implement the BLRMS for the SUS channels, we'll be able to trend the noise over long periods of time.

  11792   Fri Nov 20 09:45:39 2015 steveSummarySUSoplev laser summary






      May  13, 2014             ETMX,  .............laser in place 90 d

      May  22, 2012             ETMY, 

     Oct.  7,  2013             ETMY,  LT  503 d  or  1.4 y............bad beam quality ?

     Aug. 8,  2014              ETMY,  .............laser in place   425 days  or  1.2 y


      Sept. 5, 2014              new 1103P, sn P893516  installed at SP table for aLIGO oplev use qualification


Attachment 1: oplev_summery.png
  11878   Mon Dec 14 14:08:49 2015 SteveUpdateSUSRuby wire standoffs update

Two companies are willing to  make the ruby grooves and the third one is still working on their quote.

The price is ~$100 each. The cost goes down 10% if we  order 50 instead of 30 pieces.

How many should we get ?

  11903   Mon Dec 28 14:12:23 2015 SteveUpdateSUS4.2M EQ

Suspensions are recovered after 4.2 Mag earth quake. No obvoius sign of damage.


Attachment 1: 4.2Meq.png
Attachment 2: recovered4.2M.png
  11904   Wed Dec 30 11:09:52 2015 SteveUpdateSUS4.4M EQ

Suspensions recovered after 4.4 Mag EQ


Attachment 1: 4.4MeqDevore.png
Attachment 2: free.png
  11927   Tue Jan 12 07:54:23 2016 SteveUpdateSUSETMX damping restored

PMC locked and ETMX suspension damping restored.

  11932   Thu Jan 14 13:44:05 2016 SteveUpdateSUS earthquake 3.6M

No obvious sign of damage.


Attachment 1: 3.6M_JohannesburgCA.png
Attachment 2: ETMX_3.6_M.png
  11935   Tue Jan 19 10:25:53 2016 SteveUpdateSUSEQ 3.6M Ludlow

Just an other local earthquake 3.6 Mag Ludlow, Ca

No obvious sign of damage


Attachment 1: EQ_3.6M_Ludlow.png
  11939   Wed Jan 20 09:36:11 2016 SteveUpdateSUSETMX damping restored

ETMX suspension damping restored.


Attachment 1: EQ.png
  11948   Mon Jan 25 08:36:46 2016 SteveUpdateSUSPRM damping restored

PRM suspension damping restored after 4.1 Mag Ludlow earthquake.


Attachment 1: EQ4.1mLudlow.png
Attachment 2: EQ7.1mAlaska_4.1mLudlow.png
Attachment 3: 7.1_4.1.png
  11975   Thu Feb 4 10:14:52 2016 SteveUpdateSUS earthquake 3.5M



Attachment 1: EQ3.5m_Simmier.Ca.png
  11980   Mon Feb 8 09:37:07 2016 SteveUpdateSUS EQ 3.9m

No sign of damage


Attachment 1: EQ3.9mSimmierCa.png
  12001   Mon Feb 22 08:45:46 2016 SteveUpdateSUSEQ 4.3 grabs ITMX-UL magnet

Local EQ4.3

kicks ITMX-UL magnet into stuck position.

Hopefully it is only sticking.

Attachment 1: EQ4.3LucerneV.png
Attachment 2: ITMX-UL.png
  12003   Mon Feb 22 23:00:21 2016 ericqUpdateSUSITMX free, green is flashing

Taking inspiration from J. Lewis et. al, ITMX has been freed. 

Even better, I'm now seeing Green flashes in the X arm.  cool

  12004   Tue Feb 23 09:51:34 2016 SteveUpdateSUSITMX free

Good job Q! Give us more details please or  play Rachmaninoff Piano Concernto #2

Atm2,  EQ 3.5 and 4.1 

          confirming ITMX is really free


Taking inspiration from J. Lewis et. al, ITMX has been freed. 

Even better, I'm now seeing Green flashes in the X arm.  cool


Attachment 1: ITMX_FREED.png
Attachment 2: ITMX_FREE.png
  12005   Tue Feb 23 17:46:09 2016 gautamUpdateSUSEQ

Looks like another EQ 4.8 took out all the watchdogs, I've restored them, everything looks alright and doesn't look like any magnets got stuck this time... 

Attachment 1: SUS_Summary_23Feb.png
  12036   Wed Mar 16 15:36:03 2016 SteveUpdateSUSwire standoff test cut

Ruby wire standoff 1 mm od. with V-groove test cut. SOS sus wire 0.0017" od. is in the background.

Attachment 1: 0182_-_20160316_135935.png
  12037   Wed Mar 16 16:02:40 2016 KojiUpdateSUSwire standoff test cut

It looks almost OK, but we need a bit sharper picture for both the groove and thw wire.

Attachment 1: ruby.png
  12038   Fri Mar 18 11:04:56 2016 SteveUpdateSUSinverted pendulum

Kate Dooley picked up this item today.

Attachment 1: invPeng.jpg
  12039   Mon Mar 21 10:07:45 2016 SteveUpdateSUSETMX enclosure update

The enclosure top piece in the middle is still in the machine shop.

The carpenter who helps in the built just left for one week vacation.

The unit will be ready  on April 1

I'd prefer doing the installation with the enclosure on the new table.

It's the only way to minimize the resonances of the enclosure with shimming.

Attachment 1: ETMXenclosure.jpg
  12050   Mon Mar 28 08:30:09 2016 SteveUpdateSUSPRM damping restored

Recent  EQ 4.8 mag San Felipe, Mexico trips PRM sus damping.

PRM damping restored. PMC locked.

Attachment 1: shaking.png
  12062   Tue Apr 5 08:55:51 2016 SteveUpdateSUSlocal EQ 3.1m

Local earth quake 3.1 magnitude in Valencia, Ca did not trip our suspensions.


Attachment 1: eq3.1Valencia.png
ELOG V3.1.3-