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ID Date Author Type Category Subjectup
  5586   Fri Sep 30 16:17:10 2011 kiwamuUpdateGreen Lockingthings to be done for the Yarm green lock

Thank you for the summary.

I think now you are getting into a phase where you should start doing some quantitative and careful checks.

    1. Calculate how much light will be reflected from the cavity if the alignment is perfect.

    2. Investigate where those kHz oscillations are coming from.

    3. Estimate how much the 1.1 kHz corner frequency in LPF will reduce the phase margin around 10 kHz.

    4. Calculate the estimated amplitude of the PDH signal.

    5. Compute how big the gain of the PDH box should be.

Quote from #5585

 This is a kind of summary of what I have worked on this week. 

  • DC level of green PD when light resonates 75%
                    --> Not sure if this alignment is good enough
  • The PDH error signal was covered with oscillations of 3.3 kHz, 7.1 kHz and 35 kHz.
  • Designed and build a new LPF: second order, cut of frequency of 1.1 kHz (this is just the design value, haven't measured that so far)
  • Signal-to-noise ratio (SNR) could be improved to values between 7.8 and 11.1 (old SNR was 5 to 7)

  3787   Tue Oct 26 16:02:55 2010 yutaHowToCDSthings to do after making a new Simulink model


Things to do after making a new Simulink model.

1. ssh c1sus, go to /opt/rtcds/caltech/c1/core/advLigoRTS/ and run
 bash ./makestuff.sh c1SYS

 makestuff.sh does;

  make uninstall-daq-$*
  make clean-$*
  make $*
  make install-$*
  make install-daq-$*
  make install-screens-$*
  sed -i 's/RO \(.*SW[12]R.*\)/\1/' /opt/rtcds/caltech/c1/target/$*/$*epics/autoBurt.req

 If you don't need to re-install DAQs or screens, just run line 2,3,4, and 7 and go to step #6.

2. ssh c1sus, go to /opt/rtcds/caltech/c1/scripts/ and run
 sudo ./startc1SYS

 For now, you have to put "1" in "BURT Restore" in GDS screens with in 5-10 secs.

3. Now the DAQ channel numbers are changed. So, go to /cvs/cds/rtcds/caltech/c1/chans/daq/ and run

 activateDAQ will activate the following DAQ channels for every optics with data rate 2048Hz;

4. Restart fb. See this wiki page.
 Basically you what have to do is kill and restart daqd in fb and restart mx_streams in c1sus.

5. DONE! Burt restore if you want.

6. If you don't need to re-install DAQs or screens;
  a. Go to /opt/rtcds/caltech/c1/target/c1SYS/c1SYSepics and run
    sudo rmmod c1SYSfe

  b. Go to /opt/rtcds/caltech/c1/target/c1SYS/bin/ and run
    sudo insmod c1SYSfe.ko

  5771   Mon Oct 31 15:58:25 2011 steveUpdateSUSthinking of black glass baffles for 40m

Shade 12 black glass-green lines: 1/8" thick,  6" wide  x 7 " high  mounted on angle bracket below.  Aperture 1" diameter. Let me know what do you think.


Attachment 1: 03260901.PDF
Attachment 2: 03260902.PDF
  12357   Fri Jul 29 20:12:54 2016 gautamUpdateSUSthird time - no luck

[lydia, gautam]

Summary: Third unsuccessful attempt at getting ETMX suspended. I think we should dial the torque wrench back down to 1.0 N m from 1.5 N m for tightening the primary clamp at the top of the SOS tower. No damage to magnets, standoff successfully retrieved (it is sitting in the steel bowl)


  • We burned through two sets of wires today.
  • First, the assembly Eric and I had put together last night failed when Eric tightened the wire clamp (no torque wrench was used I think?)
  • This afternoon, Lydia and I re-assembled the suspension once again. Standoff was successfully inserted, coarse pitch balancing was achieved relatively easily - we think that the coarse pitch balance can be achieved if the end of the wire standoff closer to the groove is ~0.5mm ahead (i.e. towards HR side) of the guide rod.
  • Checked leveling of scribe lines, gave an extra 0.25 turns on the winches in anticipation of the wire sagging
  • Inserted OSEMs just short of magnets, verified that they were approximately centered, if anything, slightly above center, again in anticipation of the wire sagging. 
  • After taking pictures, we went ahead and attempted to clamp the wire (ALL EARTHQUAKE STOPS WERE ENGAGED)
  • Eric commented that the clamp piece did not slide in smoothly on the dowels (indeed it does not come off very easily either, I have just left it on for now). I don't remeber it being so difficult prior to us sending it into the maching shop to get rid of the grooves made by the suspension wire the first time around. But with the torque wrench, the piece moved in relatively easily (we had sanded down rough edges prior to putting this piece onto the suspension earlier in the afternoon.
  • I could feel that the torque wrench coming up on its limit. But the wire snapped before the torque wrench clicked. As far as I am aware, there were no rough edges on the piece, but perhaps we missed a spot?
  • I took the opportunity to discharge the optic using ionized nitrogen at 40psi. After about 2-3 minutes of a steady stream, I verified that a piece of the suspension wire no longer gets attracted to the barrel, as was the case earlier today.

Unfortunately I don't know of a more deterministic way of deciding on a "safe" torque with which to tighten the bolts except by trial and error. It is also possible that the clamping piece is damaged in some way and is responsible for these breakages, but short of getting the edges chamfered, I am not sure what will help in this regard.

Unrelated to this work: earlier today before the first wire failure, while I was optimistic about doing fine pitch balancing and gluing the standoff, I set up an optical lever arm ~3m in length, with the beam from the HeNe on the clean bench at 5.5 in above the table, and parallel to it (verified using Iris close to the HeNe and at the end of the lever arm). I also set up the PZT buzzer - it needs a function generator as well for our application, so I brought one into the cleanroom from the lab, isopropanol wiped it. The procedure says apply 5Vrms triangular wave at 1000Hz, but our SR function generators can't put out such a large signal, the most they could manage was ~2Vrms (we have to be careful about applying an offset as well so as to not send any negative voltages to the PZT voltage unit's "External input". All the pieces we need for the fine pitch balancing should be in the cleanroom now.

  12359   Mon Aug 1 14:09:20 2016 SteveUpdateSUSthird time - no luck

Gautam and Steve,

The clamp's left side was jammed onto the left guide pin. It was installed slit facing left. Gautam had to use force to remove it. The clamp should move freely seating on the guide rods till torque aplied. Do not move on with the hanging of optic with a jammed clamp. Fix it.

Never use force as you are hanging - aligning optic. The clamp is in the shop for resurfacing and slit opening.


  2466   Wed Dec 30 09:57:53 2009 steveUpdatePSLthirsty water chiller

I added 600 cc of Arrowhead Distilled Water to the chiller.

60 days plot shows that about every ~ 10 days I have to add some.

Please check the water level yourself.

Attachment 1: htemp60d.png
  3   Thu Oct 18 15:03:14 2007 ajwRoutineGeneralthis is only a test

  5166   Wed Aug 10 07:59:33 2011 steveUpdateSUSthis is too dam nice


Suresh and I tweaked the OSEM angles in ETMX yesterday.  Last night the ETMs were left free swinging, and today I ran Rana's peakFit scripts on ETMX to check the input diagnolization:


It's well inverted, but the matrix elements are not great:

       pit       yaw       pos       side      butt
UL    0.3466    0.4685    1.6092    0.3107    1.0428
UR    0.2630   -1.5315    1.7894   -0.0706   -1.1859
LR   -1.7370   -1.5681    0.3908   -0.0964    0.9392
LL   -1.6534    0.4319    0.2106    0.2849   -0.8320
SD    1.0834   -2.6676   -0.9920    1.0000   -0.1101

The magnets are all pretty well centered in the OSEMS, and we worked at rotating the OSEMS such that the bounce mode was minimized.

Rana and Koji are working on ETMY now.  Maybe they'll come up with a better procedure.


  7510   Tue Oct 9 09:29:10 2012 SteveUpdateIOOthis is where we are



 The new cold cathode gauge CC1 is in place. We were at atmosphere for 28 days ......more later


 cc1 = 2.3e-5 Torr at day 6 vacuum normal


Attachment 1: 15days.png
  11885   Wed Dec 16 10:22:14 2015 SteveUpdateIOOthis morning

c1sus and c1ioo were restarted. PMC locked.

Attachment 1: PMClocked.png
  9878   Wed Apr 30 11:16:41 2014 SteveUpdateIOOthis typical morning

c1sus and c1iscey were reset. The PMC needed to be locked. MC locked instantly.

The FSS ion pump power supply was turned on.





Attachment 1: 40days.png
  9901   Fri May 2 08:38:07 2014 SteveUpdateIOOthis typical morning


 c1sus needed reset.

Attachment 1: 2dTrend.png
  1898   Thu Aug 13 11:20:43 2009 janoschHowToPEMthree-channel self-noise estimation

There are two new Matlab files on the svn in /mDV/extra/C1. 'mycsd.m' is to calculate the cross-spectral density between two channels, 'csd_40T_40T_SS1.m' calls this function with the available seismic channels and derives a self-noise spectrum for the vertical axis using all three seismometers. The method requires that there are no correlations between two instruments only which is a bad idealization for certain frequencies if you have seismometers of totally different types.

'mycsd.m' uses the high-gain, low-resolution Nuttall window (built-in Matlab function 'nuttallwin.m'). High-gain windows are used for broad-band spectra like seismic spectra, but it should be exchanged by another window if you plan to look at small-bandwidth features like peaks.

Since the three-channel analysis does not require knowledge of response functions, it could be used to evaluate the performance of the adaptive filter. For example, if three channels responding to the same signal are available, then the ratio of any two csds corresponds to one of the relative transfer functions. You can then compare this function with the result produced by the adaptive filter.

  1129   Mon Nov 10 19:39:40 2008 steveUpdatePEMthump noise from particle counter
The particle counter is back on the IOOC location on a piece of FOAM
It needs this isolation, so when the pump is running, it's not shaking things.
The counter was counting for 6 sec and it was on holding for 20 mins.
Now I set the counter for 20 sec so it is easy to recognise it's signal and it holds for 2min only.
This will set the alarm handler in action.

Atm1: 40 mins plot
PEM-ACC_MC2_x,y,z up to 13 mins: pcounter at MC2 table, clamped, counting for 20s and holds for 2 mins
PEM-ACC_MC2_x,y,z from 13 to 26 mins: pcounter at MC2 table, not clamped, seated on 2" foam, counting 20s and holds for 2 mins
PEM-ACC_MC1_x,y,z from 26 to 40 mins: pcounter at MC1_IOOC location, not clamped, seated on 2" foam, counting 20s and holds for 2 mins

Rana won the bet

I'll bet Steve a dollar that it is mechanical. The attached PDF compares all of the accelerometers from right now.

You can see that the RMS in MC2 is way bigger than MC1.

In the second PDF file you can see the time series. I had to play around a lot with DTT to get it to work. The DTT/Foton
combo on Allegra is not stable, so make sure your work early and often.

In the plots shown, I am bandpassing the time series from 600-700 Hz. I found that doing so allowed the burp in MC1 to remain
large and reduce the extraneous fuzz in MC2. As you can see there is no such noise in MC2.

So its a noise around 600-700 Hz that comes on quickly and then shuts off after several seconds. Its also very periodic in that
it comes on around every 20 minutes. Steve also tells me (although he refuses to put in the elog) that it started up around
August 20th (?). I feel like someone in the 40m lab ought to be able to guess what this is at this point.

Please convince Steve to elog his findings about when the noise started.

If one goes out there and stands next to it when the trend predicts its happening it becomes clear what it is.
Attachment 1: partcfm.jpg
  9369   Tue Nov 12 23:05:06 2013 ranaUpdatePEMthump noise from particle counter

The particle counter is back on the IOOC location on a piece of FOAM
It needs this isolation, so when the pump is running, it's not shaking things.
The counter was counting for 6 sec and it was on holding for 20 mins.
Now I set the counter for 20 sec so it is easy to recognise it's signal and it holds for 2min only.
This will set the alarm handler in action.

Atm1: 40 mins plot
PEM-ACC_MC2_x,y,z up to 13 mins: pcounter at MC2 table, clamped, counting for 20s and holds for 2 mins
PEM-ACC_MC2_x,y,z from 13 to 26 mins: pcounter at MC2 table, not clamped, seated on 2" foam, counting 20s and holds for 2 mins
PEM-ACC_MC1_x,y,z from 26 to 40 mins: pcounter at MC1_IOOC location, not clamped, seated on 2" foam, counting 20s and holds for 2 mins

Rana won the bet

This noise source from 2008 is back. Somehow the particle counter snuck back up to the top of the BS chamber. Bad, noisy particle counter. Let's move it away from out sensitive optics and put it on the wall next to the router or maybe on some toolbox. Not on optics tables, chambers, or near them.
  1343   Fri Feb 27 13:49:19 2009 robUpdateLockingthurs night

Could not get past arm power of ~11 or so.  I was suspicious of the transmon high-gain/low-gain PD handover, so I ran the matchTransMon scripts, but that did not help.  I also removed the line in the cm_step script that increased the CM gain by 18dB at an arm power of 4.  The gain of the CM servo will increase naturally as the power in the IFO builds up, so it may not be good to crank it right away.  I tried several other CM gains, and watched the DARM loop, but still could not get past an arm power of ~10-11.  I'm not sure what's wrong, but it may be that mysterious CM-servo/McWFS conspiracy, so we can try turning down the McWFS gain next time.

  3410   Thu Aug 12 16:18:46 2010 steveUpdateEnvironmenttiles and adhesive removed


I powered down 1Y1 and 1Y2 instrument racks of MC and RF-systems this morning.

Both racks, SP table, clean tools-parts boxes and MC2 area are also covered with plastics.

Bertin Bros. Construction, Inc is working on the floor preparation. Their head man is Robby Bertin, cell 626. 831.2264

Today's job:

remove tiles, clean off tile glue, drill for ribbed  steel bars, rough clean- surface for good bounding. paint floor with bounding agent

Tiles and adhesive removed. There were no dust storms created. Solvent paint- removal made the hole IFO -lab smell like the paint shop.

The south door is open with a fan blowing air inside. The north-west door is open through control room to outside to let air rinse the drying

paint-removal. Koji is  taking lunch break while test riding our new PSL table legs.

Attachment 1: P1060604.JPG
Attachment 2: P1060606.JPG
Attachment 3: P1060603.JPG
Attachment 4: P1060610.JPG
Attachment 5: DSC_2388.JPG
  14124   Thu Aug 2 16:30:08 2018 SteveUpdateTreasuretime capsule location

I 've just found this time capsule note from Nov. 26, 2000 by Kip Thorne:  LIGO will discover gravitational waves by Dec.31, 2007


   Beautifully Done


  what is next?

Atm 3, Ron Drever could not celebrate with us because of health issues.



Attachment 1: time_capsule.JPG
  6927   Fri Jul 6 08:38:04 2012 steveUpdateComputerstime out

Why do we have these timing blanks?

Attachment 1: timingblanks.png
  15904   Thu Mar 11 14:27:56 2021 gautamUpdateCDStimesync issue?

I have recently been running into hitting the 4MB/s data rate limit on testpoints - basically, I can't run DTT TF and spectrum measurements that I was able to while locking the interferometer, which I certainly was able to this time last year. AFAIK, the major modification made was the addition of 4 DQ channels for the in-air BHD experiment - assuming the data is transmitted as double precision numbers, i estimate the additional load due to this change was ~500KB/s. Probably there is some compression so it is a bit more efficient (as this naive calc would suggest we can only record 32 channels and I counted 41 full rate channels in the model), but still, can't think of anything else that has changed. Anyway, I removed the unused parts and recompiled/re-installed the models (c1lsc and c1omc). Holding off on a restart until I decide I have the energy to recover the CDS system from the inevitable crash. For documentation I'm also attaching screenshot of the schematic of the changes made.

Anyway, the main point of this elog is that at the compilation stage, I got a warning I've never seen before:

Building front-end Linux kernel module c1lsc...
make[1]: Warning: File 'GNUmakefile' has modification time 13 s in the future
make[1]: warning:  Clock skew detected.  Your build may be incomplete.

This prompted me to check the system time on c1lsc and FB - you can see there is a 1 minute offset (it is not a delay in me issuing the command to the two machines)! I am suspecting this NTP action is the reason. So maybe a model reboot is in order. Sigh

Attachment 1: timesync.png
Attachment 2: c1lscMods.png
  3974   Tue Nov 23 10:53:20 2010 josephbUpdateCDStiming issues


Front ends seem to be experiencing a timing issue.  I can visibly see a difference in the GPS time ticks between models running on c1ioo and c1sus. 

In addition, the fb is reporting a 0x2bad to all front ends.  The 0x2000 means a mismatch in config files, but the 0xbad indicates an out of sync problem between the front ends and the frame builder.


As there are plans to work on the optic tables today and suspension damping is needed, we are holding off on working on the problem until this afternoon/evening, since suspensions are still damping.  It does mean the RFM connections are not available.

At that point I'd like to do a reboot of the front ends and framebuilder and see if they come back up in sync or not.

  9426   Mon Nov 25 12:57:54 2013 JamieUpdateCDStiming problem at c1iscex IO chassis

There is definitely a timing distribution malfunction at the c1iscex IO chassis.  There is no timing link between the "Master Timer Sequencer D050239" at the 1X6 and the c1iscex IO chassis.  Link lights at both ends are dead.  No timing, no running models.

It does not appear to be a problem with the Master Timer Sequencer.  I moved the c1iscey link to the J15 port on the sequencer and it worked fine.  This means its either a problem with the fiber or the timing card in the IO chassis.  The IO timing card is powered and does have what appear to be normal status lights on (except for the fiber link lights).  It's getting what I think is the nominal 4V power.  The connection to the IO chassis backplane board look ok.  So maybe it's just a dead fiber issue?

I do not know what could have been the problem with c1auxex, or if it's related to the fast timing issue.

  9427   Mon Nov 25 17:28:33 2013 JenneUpdateCDStiming problem at c1iscex IO chassis


There is definitely a timing distribution malfunction at the c1iscex IO chassis.  There is no timing link between the "Master Timer Sequencer D050239" at the 1X6 and the c1iscex IO chassis.  Link lights at both ends are dead.  No timing, no running models.

It does not appear to be a problem with the Master Timer Sequencer.  I moved the c1iscey link to the J15 port on the sequencer and it worked fine.  This means its either a problem with the fiber or the timing card in the IO chassis.  The IO timing card is powered and does have what appear to be normal status lights on (except for the fiber link lights).  It's getting what I think is the nominal 4V power.  The connection to the IO chassis backplane board look ok.  So maybe it's just a dead fiber issue?

I do not know what could have been the problem with c1auxex, or if it's related to the fast timing issue.

 Steve and Koji looked around, and called around, and there seem to be no spare fibers that are long enough to reach the end, so Steve has ordered

"Tripp Lite N520-30M 100' Multimode Duplex 50/125 Fiber Optic Patch Cable LC/LC"

 and it should be here tomorrow.

  9428   Wed Nov 27 14:45:49 2013 JenneUpdateCDStiming problem at c1iscex IO chassis

 [Koji, Jenne]

The new fiber arrived today, and we tried it out.  No luck.  We think it is the timing card, so we'll need to get one, since we can't find a spare.

Order of operations:

* Lay new fiber on floor, plugged it in at both ends, saw no fiber link lights.

* From control room, killed all models running on c1iscex, shutdown computer.  Still no link lights.

* Power cycled computer and IO chassis.

* Tried plugging new fiber into different port on Master Timing Sequencer, with other end still plugged in to c1iscex.  Still no link lights.

* Looked around with flashlight at Xend IO chassis.  The board that the fiber is connected to does not have a power light, although the board next to it has 2.  We compared with the SUS IO chassis, and the board there with the fiber has one power light, plus the fiber link lights, as well as 2 on the board next to the fiber.  So, perhaps there's a problem with power distribution on the timing board at the Xend? 

* Unplugged and replugged the power connector to the timing board, inside the IO chassis, board next to the fiber's board got lights back, but the fiber's board did not.  However, power must be going through the board with the fiber attached, to the next board, so there's power at least on some part of the timing board, just not the whole thing.

From this, we conclude that the blue fiber that was in place is probably fine (or is not found guilty), and that we need a replacement timing board.  Koji didn't find one in the "CDS stuff" boxes underneath the Jenne Laser, and I feel like I recall Jamie saying that we would have to get a spare from somewhere else.  We rolled up the new spare fiber, and put it in the box with other "CDS Stuff" under the Jenne Laser table.

  6911   Wed Jul 4 17:33:04 2012 JamieUpdateCDStiming, possibly leap second, brought down CDS

I got a call from Koji and Yuta that something was wrong with the CDS system.  I somehow had an immediate suspicion that it had something to do with the recent leap second.

It took a while for nodus to respond, and once he finally let me in I found a bunch of the following in his dmesg, repeated and filling the buffer:

Jul  3 22:41:34 nodus xntpd[306]: [ID 774427 daemon.notice] time reset (step) 0.998366 s
Jul  3 22:46:20 nodus xntpd[306]: [ID 774427 daemon.notice] time reset (step) -1.000847 s

Looking at date on all the front end systems, including fb, I could tell that they all looked a second fast, which is what you would expect if they had missed the leap second.  Everything syncs against nodus, so given nodus's problems above, that might explain everything.

I stopped daqd and nds on fb, and unloaded the mx drivers, which seemed to be showing problems.  I also stopped nodus's xntp:

  sudo /etc/init.d/xntpd stop

His ntp config file is in /etc/inet/ntp.conf, which is definitely the WRONG PLACE, given that the ntp server is not, as far as I can tell, being controlled by inetd.  (nodus is WAY out of date and desperately needs an overhaul.  it's nearly impossible to figure out what the hell is going on in there).  I found an old elog of Rana's that mentioned updating his config to point him to the caltech NTP server, which is now listed in the config, so I tried manually resyncing against that:

  sudo ntpdate -s -b -u

Unfortunately that didn't seem to have any effect.  This was making me wonder if the caltech server is off?  Anyway, I tried resyncing against the global NTP pool:

  sudo ntpdate -s -b -u pool.ntp.org

This seemed to work: the clock came back in sync with others that are known good.  Once nodus time was good I reloaded the mx drivers on fb and restarted daqd and nds.  They seemed come up fine.  At this point front ends started coming back on their own.  I went and restarted all the models on the machines that didn't (c1iscey and c1ioo).  Currently everything is looking ok.

I'm worried that there is still a problem with one of the NTP servers that nodus is sync'ing against, and that the problem might come back.  I'll check in again later tonight.

  13231   Mon Aug 21 09:08:54 2017 SteveUpdateSUStiny glitches

They are synchronised tiny glitches. They are not mechanical.

Attachment 1: glitches.png
  7924   Tue Jan 22 09:18:50 2013 SteveUpdateTip - Tilttip tilt bases ordered

The corrected drawing base for tip tilt with coils are going to the shop. The will be back by the end of the week.

Attachment 1: TTbc.PDF
  7627   Thu Oct 25 22:52:07 2012 janoschUpdateGeneraltip-tilt phase maps

Now that I read Koji's last elog about phase maps, I am not sure if these are still required, but here they are (the tilt-removed phase maps of the Laser Optik mirrors), first 1, 2, 3:


Then 4,5,6:


So they all have an elevated center. I am not sure why the phase maps of mirrors 5 and 6 are slightly smaller in dimension. Anyhow, all mirrors have quite strong aberrations. Also, there is no big difference between the mirrors. Check for yourself, but be careful with the colors since the scales are all different.

  7628   Thu Oct 25 23:00:44 2012 ManasaUpdateGeneraltip-tilt phase maps

Are these maps drawn from the data we extracted using Image SXM??

  7629   Thu Oct 25 23:14:42 2012 janoschUpdateGeneraltip-tilt phase maps


Are these maps drawn from the data we extracted using Image SXM??

 Indeed. So the only manipulation that I did was to remove the tilt (since this should usually be seen as an artifact of the measurement, or better, we can assume that tilt is compensated by alignment). I did not remove the curvature.

  7638   Mon Oct 29 11:27:42 2012 ManasaUpdateGeneraltip-tilt phase maps

 [Jan, Manasa]

Below are phasemaps for the tip-tilts with both tilt and RoC removed. We have not used Koji's code; but tweaked the earlier code to remove curvature.

The RoC values matched approximately to that quoted by Gari Lynn ~700m.

RoC of tip-tilts
RoC (m)
SN1 748.7176
SN2 692.7408
SN3 707.0336
SN4 625.5152
SN5 672.5340
SN6 663.7791



The color scale for height are not the same for all mirrors.


SN1, SN2 and SN3


SN4, SN5 and SN6


  7639   Mon Oct 29 14:57:41 2012 janoschUpdateGeneraltip-tilt phase maps


 [Jan, Manasa]

Below are phasemaps for the tip-tilts with both tilt and RoC removed. We have not used Koji's code; but tweaked the earlier code to remove curvature. 

 The posted residual phase maps show circular contours since the data came with relatively low resolution in height. This is ok for what we want to do with these phase maps (i.e. simulating higher-order mode content in the PRC using Finesse). Better resolution is only required if you want to understand in detail optical scattering out of the cavity. Anyhow, the circular artifacts can be removed by first interpolating the phase maps to a higher lateral resolution, and then performing tilt and curvature subtraction. So we will soon have better looking phase maps posted. Then we should think about what type of Finesse simulation we could run. Certainly one simulation is to look at the beam shape in the PRC, but more interesting could be how sensitive the shape is to mirror alignments. The current simulation shows a mode that resembles the TEM01, but I have not yet tried to find optimal alignment of the mirrors (in simulation) to search for the TEM00 mode.

  4357   Fri Feb 25 13:28:14 2011 kiwamuSummaryGeneralto do list
 Because it maybe useful to share this kind of information among us, I just put a to-do-list which has been continuously noted in my laptop.
 I guess those items can be applied for the coming two months (i.e. March and April). Anything else ?

-- Alignment

     - C1ASS

           * finalize the model and make user friendly scripts and medm screens
           * adjustment of phase rotations
           * cavity auto alignment for green

     - MC WFS 

          * put sensing matrices
          * whitening ?

    - OPLEVs

        * binary output for OPLEV whitening
        * calibration of OPLEVs  [rad/count]
        * characterization of OPLEV servos
        * bigger trans impedance gains to have reasonable readouts

-- Optimization of Suspended Optics

  - diagonalizations

         * input matrices
         * f2p with higher precision

  - damping control

        * fix ETMY damping
         * Bounce Roll notches
         * Q adjustment for damping

  - upgrading of electronics

        * bigger trans impedance gain for OSEMs
        * widen the voltage range of AA filter boards

   - weekly check

       * a routine script for measuring free swinging spectra

-- Input Optics

   - PMC

         * mode matching
         * epics LO HI values

   - FSS and ISS

        * recover FSS
        * make ISS working

   - EOM

       * AM minimization
       * triple resonant box

   - doubling and RFPD for green

        * mode matching to doubling crystal
        * connect RFPD_DC_MON to ADC
        * string +/-150 V and +/-15power cables from 1X1 rack to RFPDs
        * visibility check and loss investigations for the beat RFPD
        * rearrange RF amplifiers (ZLN series) for the RFPD
        * realgin Jenne's DCPD


-- Length Sensing and Control

   - digital system and electronics

       * characterization of RFPDs ==> SUresh/UG
       * installation of RF generation box and distribution box ==> Suresh/U
       * new LSC model and start making useful scripts (csh ? perl ? python ?)
       * binary outputs for PD whitening
       * make item lists for ordering (?)
       * draw cool diagrams for RF cable distribution and map of LSC rack.

-- Green Locking

    - X end station

           * eliminate undesired multiple spots on RFPD
           *  connect REFLPD_DCMON to ADC
           *  remote local boost
           * demodulation phase adjustment
           *  look for a high voltage amp. (bipoler)
           * installation of a mechanical shutter
           *  ETMX_TRANS CCD camera
           * analog low pass filter for temperature control

    - Y arm green locking ==> Suresh/Bryan

        * item lists
        * preparation of base mounts
        * mode matching estimation
        * mode measurement of input beam from Lightwave
        * temeperature scanning for beat location finding with IR beam
        * Installation
       * modification of PDH box

    - digital control systems

           * user friendly medm screens
           * apply proper filters for AC-DC whitened signal blending
           * add MC2 feedback path

      - noise budget

          * in-loop and out-of-loop evaluation
          * shot noise  
          * RFPD noise modeling
          * how intensity noise couples through MFD
          * electrical noise
          * frequency noise contribution from end laser and PSL
          * calibration of arm PDH signal

   - cavity scan and handing off

         * optimization of open loop transfer function for ALS
         * auto scripts   

-- misc.

   - CCD camera
        * color filters to separate IR and green (?)
   - lab laptops
        * a laptop for each end station (?)
    - dichroic TT (?)
        * large wegded and AR coated for 532nm (?)
    - epics for RS232C      
        * RS232C for doubling oven temperature


  4359   Fri Feb 25 14:50:16 2011 KojiSummaryGeneralto do list

- Put priority on the list

- Put names on the items

- Where is the CDS TO DO ==> Joe


- Remote disconnection of the greeen PDH 

- What is the situation of the PD DC for the LSC PDs?

- SUS Satelite box Resister replacement ==> Jamie

- IMC mode matching ==> Jamie/Larisa 

- Mechanical shutters everywhere

- SRM OPLEV Connection


- Better LSC whitening boards


 Anything else ?

  4364   Mon Feb 28 11:22:40 2011 josephbSummaryGeneralto do list

- Where is the CDS TO DO ==> Joe

CDS To Do:

1) Get ETMY working - figure out why signals are not getting past the AI board (D000186) to the coils.

2) Get TDS and command line AWG stuff working

3) Get c1ass and new c1lsc (with Koji) fully integrated with the rest of the system.

4) Get CDS software instructions up to date and well organized.

5) Redo cabling  and generally make it a permanent installation instead of hack job:

   a) Measure cable lengths, check connectors, wire with good routes and ensure strain relief.  Ensure proper labeling

   b) Get correct length fiber for c1sus RFM and timing.

   c) Fix up final BO adapter box and DAC boxes.

   d) Make boxes for the AA filter adapters which are currently just hanging.

   e) Get two "faceplates" for the cards in the back of the ETMY IO chassis so they can screwed down properly.

   f) Remove and properly store old, unused cables, boards, and anything else.

6) Create new documentation detailing the current 40m setup, both DCC documents and interactive wiki.

7)  Setup an Ubuntu work station using Keith's wiki instructions


Simulated Plant To Do:

1)Create simulated plant to interface with current end mass controls (say scx).

2) Create proper filters for pendulum and noise generation, test suspension.

3) Propagate to all other suspensions.

4) Working on simulated IFO plant to connect to LSC.  Create filters for near locked (assume initial green control perhaps) state.

5) Test LSC controls on simulated IFO.

6) Fix c code so there's seamless switching between simulated and real controls.

CDS Status:

MC damp dataviewer diaggui AWG c1lsc c1ioo c1sus c1iscex c1iscey RFM The Dolphins Sim.Plant Frame builder TDS Cabling
  4322   Fri Feb 18 00:35:21 2011 kiwamuSummaryGeneralto do list for Feb. 18th


  -  more precise F2P measurement and modify lockin simlink model (Kiwamu)

  -  run  C1ASS to check it (Valera)

  -  take care of CDS (Joe)

  -  MC mode matching (Jenne/Koji)

   -  RF stuff  (Suresh)

  -  mode matching for doubling crystal at PSL table (low priority)

  -  OPLEV (low priority)


 -  update the noise spectra of green locking

 -  make noise budgets

  4310   Thu Feb 17 00:43:13 2011 kiwamuSummaryGeneralto do list for tomorrow

Let's share our tasks !


==== daytime ===

 . mode matching for MC  (Jenne/Koji)

 . mode matching for doubling crystal on PSL table (Suresh/Koji)

 . f2p adjustment (Kiwamu)

 . fix daq and CDS issues (Joe)

 . increase oplev gain (low priority)

 . make ITMY camera nicer (Steve)

 . c1ass simlink model (Valera/Joe)

 . Bounce Roll notches (Suresh)


==== nighttime (after 7pm) ====

 . align everything   (at first green beam, then X arm cavity and finally IR beam)

 . update the noise spectrum of the green locking

 . estimate the noise from angle to length coupling

  11902   Sat Dec 26 10:34:43 2015 SteveUpdateGeneraltoday

PMC locked manually and PRM sus damping restored.

Attachment 1: 1d.png
  5207   Fri Aug 12 15:16:56 2011 jamieUpdateSUStoday's SUS overview

Here's an update of the suspensions, after yesterdays in-vacuum work and OSEM tweaking:

  • PRM and ETMY are completely messed up.  The spectra are so bad that I'm not going to bother posting anything.   ETMY has extreme sensor voltages that indicate that it's maybe stuck to one of the OSEMS.  PRM voltages look nominal, so I have no idea what's going on there.
  • ITMY is much improved, but it could still use some work
  • SRM is a little worse than what it was yesterday, but we've done a lot of work on the ITMY table, such as moving ITMY suspension and rebalancing the table.
  • BS looks for some reason slightly better than it did yesterday
TM   M cond(B)

      pit     yaw     pos     side    butt
UL    0.828   1.041   1.142  -0.135   1.057 
UR    1.061  -0.959   1.081  -0.063  -1.058 
LR   -0.939  -0.956   0.858  -0.036   0.849 
LL   -1.172   1.044   0.919  -0.108  -1.035 
SD    0.196  -0.024   1.861   1.000   0.043

ITMY  ITMY.png       pit     yaw     pos     side    butt
UL    1.141   0.177   1.193  -0.058   0.922 
UR    0.052  -1.823   0.766  -0.031  -0.974 
LR   -1.948  -0.082   0.807  -0.013   1.147 
LL   -0.859   1.918   1.234  -0.040  -0.957 
SD   -1.916   2.178   3.558   1.000   0.635 
BS  BS.png       pit     yaw     pos     side    butt
UL    1.589   0.694   0.182   0.302   1.042 
UR    0.157  -1.306   1.842  -0.176  -0.963 
LR   -1.843  -0.322   1.818  -0.213   0.957 
LL   -0.411   1.678   0.158   0.265  -1.038 
SD    0.754   0.298  -3.142   1.000   0.053


  5453   Mon Sep 19 01:38:00 2011 kiwamuUpdateLSCtoday's locking activity

[Anamaria / Kiwamu]

 The incident beam pointing was improved by using PZT1 and PZT2. 

With some triggers the lock of PRMI became smoother.

For the DRMI lock, the MICH and SRCL signals on AS55 are not quite decoupled, so we should find cleaner signals for them.


(what we did)

 + locked the Y arm

 + aligned incident beam by using PZT1(#5450) and PZT2. The spot positions on ITMY and ETMY are now well-centered.

 + tried activating C1ASS but failed. It needs some gain changes due to the new PZT1 response.

 + locked the X arm

 + aligned the TRX PD (Thorlab signal PD) and set the trigger.

 + C1ASS also doesn't work for the X arm

 + realigned the PRM and BS oplevs. the PRM oplev was clipped at a steering mirror on the optical bench

 + locked PRMI and aligned the PRM mirror such that the optical gain was maximized

 + optimized the demod phase of AS55 and REFL11

 + checked the UGF of the MICH and PRCL lock. The UGF of MICH is about 100Hz with gain of -20, and the UGF of PRCL was 85 Hz with gain of 0.1

 + adjusted the output matrix such that the MICH control doesn't couple into the PRCL control.

 + set the triggers for the MICH and PRCL control to make the lock acquisition smoother.

 + tried locking DRMI and it was sort of locked. However the SRCL signal showed up a lot in AS55_Q, where the MICH signal is extracted.

  4299   Tue Feb 15 11:53:02 2011 kiwamuSummaryGeneraltoday's missions

I think this week is going to be an "alignment week".

The goal is to get a good alignment on X arm for both the green and the IR beam in order to reduce a2l couplings.


Today's missions are :

 - fixing the oplev channel names (see here)

 - fixing the oplev gain issue (see here)

 - engage the oplev servos

 - f2p adjustment

 - make a realtime lockin model for the f2p measurement and the dithering technique

 - alignment of the MC incident beam  (because we installed a new PMC this morning)

 - manual alignment of the IR beam by steering PZT1 and PZT2 (this procedure will be replaced by an automatic way soon)

 - bounce roll filters (see here)


  3021   Mon May 31 17:47:34 2010 kiwamuUpdateIOOtoday's plan : MC alignment

[Alberto, Kiwamu]

0. have a coffee and then dress up the clean coat.

1. level the MC table

2. lock and align MC 

3. run A2L script to see how much off-centering of the spots

4. steer the periscope mirror <--- We are here

5. move the pick off mirror which is used for monitoring of MCT CCD

6. check the leveling and move some weights if it's necessary

7. shut down

  4546   Wed Apr 20 20:42:55 2011 kiwamuUpdateVIDEOtoday's video session

[Steve / Suresh / Kiwamu]

90 % of unused video cables have been removed.

Still a couple of video cables are floating around the video MUX. They will be removed in the next week's session.




  5245   Tue Aug 16 04:28:09 2011 kiwamuUpdateGeneraltoday's work to do

The main goal of today is to extract the pick-off beams

Today's menu :

  + If necessary steer ETMs and ITMs to make the X and Y green beam flashing.

  + Open the IOO and OMC chamber and lock MC.

       => cover the place of the access connector by a large piece of aluminum foil. It will give a robust lock of MC.

  + Check the beam pointing down to Y arm by looking at the ETMY face camera.

        => If it's necessary align PZT1 and PZT2 from EPICS to make the IR beam flashing in the X arm.

  + Align BS and let the beam hit the center of ETMX to make the X arm flashing.

        => These alignment procedure will automatically gives us the MICH fringes on the AS CCD camera.

  + Rotate the SRM tower to get the SRMI fringes on the AS CCD camera.

        => This is because the required amount of the YAW correction on SRM is currently beyond the range of the DC bias.

  + Align PRM to get the PRMI fringes on AS CCD camera. Also make sure the beam comes back to the REFL CCD camera.

  + Lock the PRC to make POP/POX/POY bright enough.

     => Probably the REFL11 RFPD needs more power. To increase the power, just rotate the HWP, which is sitting before the RFPDs on the AS table.

     => If the signal on AS55 is too small, we can use REFL11_Q or REFL55 for the MICH lock.

  + OR inject and align the ABSL laser to make those pick-off beams bright enough.

     => This case we don't have to make the DRMI exactly on the resonance, what we need is just the DRMI flashing.

  + Align necessary optics for those pick-off beams.

     => In our definition (aLIGO definition) POP is the beam propagating from BS to PRM. Don't be confused by another one, which propagates from PRM to BS.

  + Steer two mirrors on the ETMY table for aligning IPANG. Also, steer some mirrors on the BS table for IPPOS.

    => IPANG has already reached the ETMY table, so ideally we don't have to steer a mirror on the BS table.

    => IPPOS/ANG are very visible with a sensor card.

  + Align some oplevs.

     => This work is relatively independent from the other tasks. Steve can take care of it.

  + Adjust the OSEM to their mid-range.

     => This work can be done anytime, but everytime we have to recover the alignment of the interferometer.

  5248   Tue Aug 16 11:49:17 2011 jamie, jenneUpdateGeneraltoday's work to do

>If necessary steer ETMs and ITMs to make the X and Y green beam flashing.

Green is now flashing in both X and Y arms

>Open the IOO and OMC chamber and lock MC.

Open, and cover in place. MC is flashing and locking.


  5250   Tue Aug 16 17:09:55 2011 JenneUpdateGeneraltoday's work to do


  + Rotate the SRM tower to get the SRMI fringes on the AS CCD camera.

        => This is because the required amount of the YAW correction on SRM is currently beyond the range of the DC bias.

 Kiwamu aligned things for me, and I rotated the SRM tower so that the reflected beam was pretty much totally overlapping the incident beam.  The SRC was aligned to make sure things were good.  Now the DC bias for SRM Yaw is ~1.4, so we're totally good. 

To rotate SRM, Jamie had the idea of using 2 screws so I could push the tower on one side, and back off the screw an equal amount on the other side and push the tower to be touching both screws again, to ensure that I was rotating about the center of the tower and wasn't introducing any Pos action. 

While I was at it, I also moved the OSEM connector tower back to its normal place on the table, so it's not in the way of oplev beams.  It had been moved previously to accommodate ITMY near the door.

  3496   Tue Aug 31 14:47:53 2010 steveConfigurationPEMtoilet upgrade

Our toilets were replaced by a green Gerber 1.6 gpf ( 6 lpf ) last week.

Attachment 1: toil-n.JPG
  14191   Wed Aug 29 14:51:05 2018 SteveUpdateGeneraltomorrow morning

Electrician is coming to fix one of the fluorenent light fixture holder in the east arm tomorrow morning at 8am. He will be out by 9am.

The job did not get done. There was no scaffolding or ladder to reach troubled areas.

  5553   Tue Sep 27 04:13:22 2011 kiwamuUpdateLSCtonight's locking activity

The lock of PRMI wasn't so robust although it could stay locked for more than 10 minutes.

There have been 2-3Hz spikes in everywhere. It needs to be investigated.


(to do)

 + Diagnosis on the suspensions.

 + Check the beam centering on the RFPDs.

 + Check the f2a filters on PRM and BS.

 + Health check of the suspensions by locking some cavities and measuring the noise spectra for comparison.

 + Trying to use another signal port other than AS55.



 The attached picture below is an example of the REFLDC and POXDC signals in time series.

This was when PRCL and MICH were locked by REFL33_I and AS55_Q respectively.


Note that when PRMI is unlocked, REFLDC goes to ~ 5000 counts and POXDC goes within ADC noise of ~ 1 counts.

According to the POP camera it looked like something was oscillating in the YAW direction which coincided with the spikes.

I tried finding any suspicious angular motions in the ITMs, BS and PRM olevs, but none of them showed the 2-3 Hz feature.

  4601   Mon May 2 21:14:55 2011 kiwamuUpdateElectronicstoo loose Heliax connectors on 1Y2 rack

I found that all the Heliax cables landing on the bottom of 1Y2 were too loose.

Due to this loose connection the RF power at 55 MHz varies from -34 dBm to 3 dBm, depending on the angle of the Heliax's head.



The looseness basically comes from the fact the black plate is too thick for the Heliax cable to go all the way. It permits the Heliax's heads to rotate freely.

What we should do is to make countersinks on the black plate like this:



ELOG V3.1.3-