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ID Date Author Typeup Category Subject
  1370   Sun Mar 8 23:09:26 2009 ranaUpdateComputersNot even data retrieval working
Although getting the regular DAQ data works, we can't get any testpoints.

I tried restarting tpman several times; there's no inittab on fb40m for this so we should get Alex to set one up when he comes.
I also tried various power cycles and reboots: daqawg, daqctrl, etc. I also notice that Osamu's setup of new stuff is connected to
the same rack and power strips as all of our sensitive DAQ machines. We should find out if there was any hardware installed in the
last couple days; it would be easy to accidentally unplug or damage on of our fibers.

I moved the old tpman.log over to tpman.log.090308. It starts out with a header and then just lists when each TP is requested.

When restarting tpman it puts the following into the terminal:
fb:controls>./tpman &
[1] 1037
fb:controls>VMIC RFM 5565 (0) found, mapped at 0x2868c90
VMIC RFM 5579 (1) found, mapped at 0x2868c90
Could not open 5565 reflective memory in /dev/daqd-rfm1
16 kHz system
Spawn testpoint manager
Channel list length for node 0 is 4168
Test point manager (31001001 / 1): node 0
which is OK?; its the same startup outputs that are in the old log file. It would be nice if there was not and error message about the RFM.
Requesting new testpoints via tdsdata, dtt, or the diag command line doesn't seem to work. tpman doesn't spit anything out although 'tp show 0'
does show that the TP is selected.

Once Alex fixes the 'tpman' issue, we should make sure to put an inittab or startup script in there so that tpman writes a log
file and also archives its old log files upon a restart.
  1371   Sun Mar 8 23:14:52 2009 ranaUpdateComputer Scripts / Programstdsdata doesn't work

Matt logged in and rebuilt the TDS stuff for us on Mafalda in /cvs/cds/caltech/apps/linux/tds_090304.

He says that he can't build his stuff on 64-bit because there's not a sanctioned 64-bit build of GDS yet.

This should have all the latest fixes in it. I tried using both the old and new code from allegra and they both are fine:

./tdsdata 16384 2 C1:IOO-MC_F > /users/rana/test.txt

I loaded the data I got with the above command and there were no data dropouts. Possibly the dropout problem is only

associated with testpoints and so we have to wait for the TP fix.

  1373   Mon Mar 9 11:09:33 2009 AlbertoUpdateComputersRe: Not even data retrieval working

Quote:
Although getting the regular DAQ data works, we can't get any testpoints.

I tried restarting tpman several times; there's no inittab on fb40m for this so we should get Alex to set one up when he comes.
I also tried various power cycles and reboots: daqawg, daqctrl, etc. I also notice that Osamu's setup of new stuff is connected to
the same rack and power strips as all of our sensitive DAQ machines. We should find out if there was any hardware installed in the
last couple days; it would be easy to accidentally unplug or damage on of our fibers.

I moved the old tpman.log over to tpman.log.090308. It starts out with a header and then just lists when each TP is requested.

When restarting tpman it puts the following into the terminal:
fb:controls>./tpman &
[1] 1037
fb:controls>VMIC RFM 5565 (0) found, mapped at 0x2868c90
VMIC RFM 5579 (1) found, mapped at 0x2868c90
Could not open 5565 reflective memory in /dev/daqd-rfm1
16 kHz system
Spawn testpoint manager
Channel list length for node 0 is 4168
Test point manager (31001001 / 1): node 0
which is OK?; its the same startup outputs that are in the old log file. It would be nice if there was not and error message about the RFM.
Requesting new testpoints via tdsdata, dtt, or the diag command line doesn't seem to work. tpman doesn't spit anything out although 'tp show 0'
does show that the TP is selected.

Once Alex fixes the 'tpman' issue, we should make sure to put an inittab or startup script in there so that tpman writes a log
file and also archives its old log files upon a restart.


Alex fixed the problem. It was caused by the awgtpman running on kami1.martian which conflicted with the tpman in fb0.

Killing awgtpman on kami1 allowed for the tpman on tp0 to work properly again.

If more test points are needed, Alex suggested to tune the GDS settings accordingly.
What this actually means, I still have to understand it.
  1374   Mon Mar 9 12:04:18 2009 YoichiUpdateComputersTPs and AWG are back
I had to do one more reboot of tpman and daqd to get the TPs working.
I confirmed the alignment scripts run fine.

Now the oplevs of some optics are largely mis-centered. Alberto and I will center them after lunch.
  1375   Mon Mar 9 14:57:30 2009 KakeruUpdateComputer Scripts / Programstdsdata doesn't work

I tested new tdsdata and found it was working well.

I excited C1:SUS-ITMY_SUSPIT_EXC with tdssine, and get data from C1:LSC-TRY_OUT (testpoint) and C1:SUS- ITMY_OPLEV_PERROR (recorded point) with new and old tdsdata.

With old tdsdata (/cvs/cds/caltech/apps/linux/tds/bin/tdsdata), I found some jumps of datapoint, which is a same problem with before (Attachment 1).

With new tdsdata (/cvs/cds/caltech/apps/linux/tds_090304/bin/tdsdata), there looks to be no jumps (Attachment 2; taken about 10 minutes after Attachment 1).

The problem of old tdsdata looks to be remaining even for recordedpoints.

You should use /cvs/cds/caltech/apps/linux/tds_090304/bin/tdsdata.

Quote:

Matt logged in and rebuilt the TDS stuff for us on Mafalda in /cvs/cds/caltech/apps/linux/tds_090304.

He says that he can't build his stuff on 64-bit because there's not a sanctioned 64-bit build of GDS yet.

This should have all the latest fixes in it. I tried using both the old and new code from allegra and they both are fine:

./tdsdata 16384 2 C1:IOO-MC_F > /users/rana/test.txt

I loaded the data I got with the above command and there were no data dropouts. Possibly the dropout problem is only

associated with testpoints and so we have to wait for the TP fix.

 

Attachment 1: oldtds.png
oldtds.png
Attachment 2: newtds.png
newtds.png
  1376   Mon Mar 9 16:54:52 2009 Kakeru, RanaUpdateComputer Scripts / Programstdsdata doesn't work

We confirmed that new tds(/cvs/cds/caltech/apps/linux/tds_090304/) works well on linux 64, and replaced it to /cvs/cds/caltech/apps/linux/tds/

The old /cvs/cds/caltech/apps/linux/tds is put in /cvs/cds/caltech/apps/linux/tds.bak

  1379   Mon Mar 9 19:33:10 2009 ranaUpdateDMFseisBLRMS in temp condition

The seisBLRMS has been running on megatron via an open terminal ssh'd into there from allegra with matlab running. This

is because I couldn't get the compiled matlab functionality to work.

Even so, this running script has been dying lately because of some bogus 'NDS' error. So for today I

have set the NDS server for mDV on megatron to be fb40m:8088 instead of nodus.ligo.caltech.edu. If this seems to fix the problem

I will make this permanent by putting in a case statement to check whether or not the mDV'ing machine is a 40m-martian or not.

Attachment 1: Untitled.png
Untitled.png
  1380   Mon Mar 9 23:13:22 2009 YoichiUpdateComputer Scripts / Programstdsdata doesn't work

Quote:

We confirmed that new tds(/cvs/cds/caltech/apps/linux/tds_090304/) works well on linux 64, and replaced it to /cvs/cds/caltech/apps/linux/tds/

The old /cvs/cds/caltech/apps/linux/tds is put in /cvs/cds/caltech/apps/linux/tds.bak

 The tdscntr.pl in the new tds was probably the one from LLO, which is actually the version I sent to Tobin. It had paths and channel names defined for the LLO. So I copied back my original 40m version.

  1382   Tue Mar 10 04:55:41 2009 YoichiUpdateLockingLocking: 3.7kHz large oscillation
Yoichi, Jenne, Alberto,

As I reported on the last Thursday, there is a large oscillation in CARM and DARM error signals (attm1).
I put notch filters (3.75kHz, Q=10, 30dB) in the CARM and DARM loops. This let us go up to the arm power of more than 20 and stay there for a while.
The dashed curves in the attm1 are the spectra when the notches are off, and the solid curves are when the notches are used.
We could somewhat suppress the DARM peaks but not CARM.
Of course this is clearly not a good solution. We should find the cause of the oscillation and kill it.

Attm2 is the spectrum of the PO_DC signal flowing in the CM board measured by the SR785. More specifically, CH1 is TP1A and CH2 is TP2A of the CM board.
This was taken right after the AO path was engaged. At this stage, the AO path gain is very low. But you can already see a seed of the oscillation in the spectrum.

Attm3 shows the same spectra taken after the arm power is increased to 4 but before the PO_DC hand off. You can see large peaks around 3.75kHz.
After this, the peaks grow as the power goes up.

Attm4 is the loop gain of the AO path after the PO_DC hand off (arm power = 4).
Attm5 is the zoom of the same TF around 3.7kHz. Clearly there is something wrong at this frequency. We should check the CM board and the MC board as well as the SPOB PD.

One time I was able to go up to arm power = 27 or so. At this power level, the DARM loop started to oscillate, probably, around the UGF.
However because of the 3.7kHz problem, we can't stay at this power level long enough to make diagnostic measurements (like open loop TF).
We should tackle the 3.7kHz issue first.
Attachment 1: CARM_DARM_Spectra.pdf
CARM_DARM_Spectra.pdf
Attachment 2: PODC_Spe_AOPath_Engaged.png
PODC_Spe_AOPath_Engaged.png
Attachment 3: PODC_Spe_before_PODC_handoff.png
PODC_Spe_before_PODC_handoff.png
Attachment 4: AOGain3.png
AOGain3.png
Attachment 5: AOGain2.png
AOGain2.png
  1386   Wed Mar 11 14:51:01 2009 Kakeru, Joe, RobUpdateIOOMC alignment

This morning, MC alignment was gone and MC wasn't lock.

We checked old value of pitch, yaw, and position offset of each MC mirror, and found they were jumped.

We don't know the reason of this jump, but we restore each offset value and MC backed to lock.

  1387   Wed Mar 11 16:41:22 2009 steveUpdateMOPAspare NPRO power

The spare M126N-1064-700,  sn 5519 of Dec 2006 rebuilt  NPRO's power output

 measured   750mW at DC2.06A with Ohpir meter.

Alberto's controller  unit 125/126-OPN-PS,  sn516m was disconnected from lenght measurment NPRO on the AP table.

5519 NPRO  was clamp to the optical table  without heatsink and it was on for 15 minutes.

  1388   Wed Mar 11 16:53:48 2009 YoichiUpdateLockingJunks in around kHz
Rana, Yoichi

Last night, we tried to find out the source of the kHz region peaks in the DARM and CARM error signals.
These peaks are also present in the error signal of the single arm locking by RF (both X and Y).
The attachment 1 shows spectra of MC_F and XARM error signal when XARM is locked by the POX PDH signal.
There is a sharp peak at 3.8kHz in MC_F. This peak was there in a reference spectrum taken on June 24 2008.

In the XARM error signal, there is also a broad peak around 3.8kHz. This peak moves between 3.75kHz and 3.8kHz from time to time.
(the brown curve was taken when the peak moved to 3.75kHz).
Also there is a notch like structure at 3.8kHz in the XARM error spectrum. Looks like the peak in the MC_F is creating a notch here, but
no idea why.

We tapped on the PSL table, the end chambers and the SPOB table and looked at the spectra to see if there is any change.
Rana also developed a cool Walkie-Talkie excitation technique, where he put one of the walkie-talkies on the PSL table by the MZ and yelled at the other one while looking at a DTT screen in the control room.
None of these had any effect on the XARM error, while MC_F responded to the disturbances.

We also turned on and off the steering mirror PZT closed loop buttons, moved the PMC, MZ and the ISS gain sliders and changed the MC gain, offset.
Nothing affected the XARM error.

Osamu found old spectra of the XARM signal (attm2). The legends say DARM but these are XARM signals.
Almost the same structures can be seen including the notch at 3.8kHz. Seems like it's been like this for long time.

We should check, RF-AM, MC coil dirivers, Piezo-Jena noise etc.
Attachment 1: MC_F-XARM.pdf
MC_F-XARM.pdf
Attachment 2: old-xarm.pdf
old-xarm.pdf
  1389   Wed Mar 11 21:03:51 2009 Kakeru and KiwamuUpdateIOOPSL angle QPD

Kakeru and Kiwamu

We placed a QPD on the PSL bench for PSL angle monitor.

 

Quote:

I checked a broken QPD, which was placed for PSL angle monitor, and finally I cocluded one segment of the quadrant diode was broken.

The broken segment has a offset voltage of -0.7V after 1st I-V amplifier. It means the diode segment has a current offset without any injection of light.

Tomorrow I will check a new QPD for replacement.

Kiwamu IZUMI

 

 As we mentioned before, old QPD which used to be placed is broken.

 And we put broken QPD into the "photodiodes" box under the soldering table.

 

 

  1390   Wed Mar 11 22:57:48 2009 YoichiUpdateLockingCalibrated XARM error signal spectrum
I did a rough calibration of the XARM error spectrum.
See the attached calibrated spectrum.

I started from this Rana's elog entry.
http://www.ldas-sw.ligo.caltech.edu/ilog/pub/ilog.cgi?group=40m&task=view&date_to_view=04/07/2005&anchor_to_scroll_to=2005:04:07:20:28:36-rana

I first injected a 20Hz sin signal into C1:SUS-ETMX_LSC_EXC and measured the response to the ETMX SUSPOS.
Using the calibration of the SUSPOS given in the above entry, I calibrated the ETMX coil actuation efficiency.
It was 3.4e-12 m/cnt @20Hz for C1:SUS-ETMX_LSC_EXC.

Then I locked the X-arm and injected a calibration peak at 20Hz.
From the ratio of the peaks in C1:SUS-ETMX_LSC_IN2 and C1:LSC-XARM_IN1, I calibrated the X-arm error signal to be 4.2e-13 m/cnt.
We have to also take into account the cavity pole of the arm, 1525Hz (the design value, may not be actual).
So I used the following calibration in the DTT:

G: 4.2e-13
P: 1525
Z:

Note that the attached spectrum shows the actual motion of the X-arm (or equivalent frequency noise) after suppressed by the feedback servo,
unlike conventional noise spectra showing "virtual" displacement which would have been induced in the absence of servos.
Attachment 1: XarmErrorSpeCalibrated.pdf
XarmErrorSpeCalibrated.pdf
  1391   Wed Mar 11 23:41:33 2009 Kakeru, YoichiUpdateIOOWFS centering

We found the MC reflection was distorted . And WFC beam went to upward of QPD

We recentered WFC beam and these problems were fixed

  1393   Thu Mar 12 02:18:42 2009 YoichiUpdateLockingMC_I spectra (RF_AM)
I took several spectra of MC_I signal (see attm1).

The blue curve is when the MC was locked. The green curve (RF_AM) shows the MC_I spectrum when the MC is unlocked and MC2 is mis-aligned,
so that no resonance should happen. The brown curve is when the PSL shutter was closed (dark noise).
There are some structures in the green curve but not at 3.8kHz.

The second attachment compares the MC_I spectrum (the same as the green one in the first attachment) with the Xarm error signal.
Of course these two spectra were taken at different times.

Some of the peaks in the X-arm error signal seem to be coming from the MC RF_AM.
Attachment 1: MC_I_Spe.png
MC_I_Spe.png
Attachment 2: MC_I-Xarm.png
MC_I-Xarm.png
  1394   Thu Mar 12 15:57:53 2009 YoichiUpdateIOOMC drift is terrible
Yoichi, Osamu,

Last night's locking work was totally interrupted by the sabotage by the MC.

First, after I measured the RF_AM, the MC alignment was somehow shifted largely and the MC did not lock to TEM00 mode.
I only mis-aligned MC2 to measure the RF_AM, but the MC reflection beam was also shifted (looking at the WFS QPD), that means MC1 was mis-aligned somehow.
Moreover, even when the MC is not locked, i.e. no feedback to the mirrors, the OSEM values of the MC mirrors (all of them) drift a lot in 10min scale.
I was totally puzzled. So I rebooted c1iovme and c1sosvme. Then this strange drift of the OSEM values stopped.
Even though, the MC tended to lose lock within ten minutes because the WFS QPDs were not centered.
We did several iterations of re-centering and finally the MC started to stay locked happily. The MC reflection beam was symmetric.

Then this morning when I came in (to be honest, afternoon), the MC reflection looked asymmetric again. The WFS QPDs were mis-centered again.
The attached files show an 8-hour trend of various MC related signals.
There was a half-degree temperature change starting from around 11AM. Corresponding to that, the IOO-QPD signals drifted indicating that the PSL beam pointing
was shifted. The MZ PZT signal shows a similar trend, so the beam pointing may have been shifted by the MZ (not sure).
The MC WFS, transmission QPD signals show the same trend.
This is too bad.

Right now, the PSL beam pointing is monitored by the QPDs detecting the transmitted beam through the first mirror of the periscope.
This means even if we can track the beam pointing drift with the QPDs, we can't correct the beam pointing using the periscope mirrors.
I don't want to touch the MZ mirrors for this purpose.
I propose to put a pick-off mirror after the second mirror of the periscope to send light to the IOO-QPDs. This way, we can use the periscope
mirrors to restore the beam pointing screwed up by the MZ.
Attachment 1: MC_Drift-1.pdf
MC_Drift-1.pdf
Attachment 2: MC_Drift-2.pdf
MC_Drift-2.pdf
  1395   Thu Mar 12 18:44:02 2009 YoichiUpdatePSLMZ aligned
The MC lost the alignment somehow this afternoon.
So I thought it was good time to touch the MZ because I had to align the MC using the periscope anyway.

I mainly touched the mirror with a PZT. The MZ reflection went down from 0.5 to 0.3.
  1396   Thu Mar 12 18:48:37 2009 YoichiUpdateIOOMC aligned but ...
After the MZ alignment, I aligned the MC with the periscope mirrors.
It looked like the MC mis-alignment was mainly caused by the input beam change.
So I left the MC mirrors as they were to keep the output beam pointing.
However, after I finished the alignment, the MC output beam was too low on the Faraday.
Also the X-arm did not lock to TEM00 mode. So the MC mirrors must have also shifted to a weird alignment state.
I should have restored the MC mirror alignment to a good state using the OSEM DC signals.

Rana came in and restored the MC mirror alignment using the SUS drift mon.
He and Kakeru is now working on the periscope to align the beam into the MC.
  1397   Thu Mar 12 19:11:27 2009 ranaUpdateIOOMC drift is terrible
Kakeru, Rana, Yoichi

We used the SUS DRIFT MON screen to set the MC biases such that the mirrors were returned to the old OSEM values.
To do this, we set the nominals and tolerances using the appropriate scripts in the mDV/extra/C1/ directory.

We then used the MC_ALIGN screen to set the angle bias sliders.

Then Kakeru and I went to the PSL table to the periscope magic and maximize the MC transmission. Kakeru seems to
have the careful Japanese alignment touch and I am hungry, so I am leaving him to optimize the power. After he
finishes he is going to align the beam to the WFS and turn the MC autolocker back on. The x-arm is locked on a
TEM00 mode so the MC alignment is maybe OK.
  1398   Thu Mar 12 20:59:04 2009 KakeruUpdateIOOMC drift is terrible
After Rana went for his dinner, I aligned periscope to make the MC output 3.2 (Attachment 1).

After that, to align WFS, I unlocked the MC, unlocked the MZ and decrease the beam power to WFS QPD, and re-centerd WFC beam.
I restored MZ and MC lock.
I enabled MC autolocker, and change C1:IOO-WFS_Gain_Slider from 0 to 0.02 to lock WFS.


Quote:
Kakeru, Rana, Yoichi

We used the SUS DRIFT MON screen to set the MC biases such that the mirrors were returned to the old OSEM values.
To do this, we set the nominals and tolerances using the appropriate scripts in the mDV/extra/C1/ directory.

We then used the MC_ALIGN screen to set the angle bias sliders.

Then Kakeru and I went to the PSL table to the periscope magic and maximize the MC transmission. Kakeru seems to
have the careful Japanese alignment touch and I am hungry, so I am leaving him to optimize the power. After he
finishes he is going to align the beam to the WFS and turn the MC autolocker back on. The x-arm is locked on a
TEM00 mode so the MC alignment is maybe OK.
Attachment 1: MCtrans090312.png
MCtrans090312.png
  1399   Fri Mar 13 05:16:21 2009 YoichiUpdateLockingLocking update
Yoichi, Osamu,

With adjustments of the loop gains during the CARM offset reduction, the IFO reaches arm_power = 25 sort of robustly unless the 3.8kHz oscillation rings up.
At arm_power = 25, the CARM and DARM start to oscillate at around 400Hz. Probably I need more gain tweaks.
Annoying thing is that the 3.8kHz oscillation sometimes rings up suddenly and kills the lock.
This can happen anywhere above arm_power = 6 or so.
Because of a strange structure in the CARM loop gain around 3.8kHz, we cannot increase the CARM UGF beyond 1kHz.
The attached plots are the AO path open loop transfer function (attm2 is the zoom of attm1) measured at arm_power = 13.

Tomorrow, I will lock the X-arm and measure the transfer function from the AO path input to the X-arm error signal to see
if there is the same structure at 3.8kHz (X-arm error signal has the 3.8kHz peak).
Attachment 1: AOTF2.png
AOTF2.png
Attachment 2: AOTF2-zoom.png
AOTF2-zoom.png
  1400   Fri Mar 13 19:26:09 2009 YoichiUpdateDMFseisBLRMS compiled

 I compiled seisBLRMS.

The tricks were the following:

(1) Don't add path in a deployed command.
It does not make sense to add paths in a compiled command because it may be moved to anywhere. Moreover, it can cause some weird side effects. Therefore, I enclosed the addpath part of mdv_config.m in a "if ~isdeployed ... end" clause to avoid adding paths when deployed. Instead of adding paths in the code, we have to add paths to necessary files with -I options at the compilation time. This way, mcc will add all the necessary files into the CTF archive.

(2) Add mex files to the CTF archive by -a options.
For some reason, mcc does not add necessary mex files into the CTF archive even though those files are called in the m-file which is being compiled. We have to add those files by -a options.

(3) NDS_GetData() is slow for nodus when compiled.
NDS_GetData(), which is called by get_data() stops for a few minutes when using nodus as an NDS server.
This problem does not happen when not compiled. I don't know the reason. To avoid this, I modified seisBLRMS.m so that when an environmental variable $NDS is defined, it will use an NDS server defined in this variable.

I wrote a Makefile to compile seisBLRMS. You can read the file to see the details of the tricks.
I also wrote a script start_seisBLRMS, which can be found in /cvs/cds/caltech/apps/DMF/compiled_matlab/seisblrms/. To start seisBLRMS, you can just call this script.
At this moment, seisBLRMS is running on megatron. Let's see if it continues to run without crashing.

Quote:

The seisBLRMS has been running on megatron via an open terminal ssh'd into there from allegra with matlab running. This

is because I couldn't get the compiled matlab functionality to work.

Even so, this running script has been dying lately because of some bogus 'NDS' error. So for today I

have set the NDS server for mDV on megatron to be fb40m:8088 instead of nodus.ligo.caltech.edu. If this seems to fix the problem

I will make this permanent by putting in a case statement to check whether or not the mDV'ing machine is a 40m-martian or not.

  1401   Fri Mar 13 20:23:37 2009 YoichiUpdateLSCAO path transfer function with X-arm locked
I measured the AO path transfer function while the X-arm is locked with the POX PDH signal.
The POX-I signal was already connected to the input 1 of the CM board. So I injected a signal from the EXC-B channel of the board and measured the transfer function from TP2B to TP1A. To open the loop, I disabled the switch befor the EXC-B.
The attached plot shows the measured transfer function.
There is a bump around 2kHz, which can also be seen in the AO path TF posted in elog:1399, but not the large structure at around 3.8kHz.
The 3.8kHz structure is probably created by the feedback.
Attachment 1: AOPath-Xarm.png
AOPath-Xarm.png
  1402   Fri Mar 13 22:07:14 2009 YoichiUpdateLockingCalibrated XARM error signal spectrum
Of course I made a mistake.
I put a pole at 1525Hz whereas it should have been a zero.

The correct calibration factor is:
G: 4.2e-13
P:
Z: 1525

I attached a revised spectrum.


Quote:
I did a rough calibration of the XARM error spectrum.
See the attached calibrated spectrum.

I started from this Rana's elog entry.
http://www.ldas-sw.ligo.caltech.edu/ilog/pub/ilog.cgi?group=40m&task=view&date_to_view=04/07/2005&anchor_to_scroll_to=2005:04:07:20:28:36-rana

I first injected a 20Hz sin signal into C1:SUS-ETMX_LSC_EXC and measured the response to the ETMX SUSPOS.
Using the calibration of the SUSPOS given in the above entry, I calibrated the ETMX coil actuation efficiency.
It was 3.4e-12 m/cnt @20Hz for C1:SUS-ETMX_LSC_EXC.

Then I locked the X-arm and injected a calibration peak at 20Hz.
From the ratio of the peaks in C1:SUS-ETMX_LSC_IN2 and C1:LSC-XARM_IN1, I calibrated the X-arm error signal to be 4.2e-13 m/cnt.
We have to also take into account the cavity pole of the arm, 1525Hz (the design value, may not be actual).
So I used the following calibration in the DTT:

G: 4.2e-13
P: 1525
Z:

Note that the attached spectrum shows the actual motion of the X-arm (or equivalent frequency noise) after suppressed by the feedback servo,
unlike conventional noise spectra showing "virtual" displacement which would have been induced in the absence of servos.
Attachment 1: XarmErrorSpeCalibrated.pdf
XarmErrorSpeCalibrated.pdf
  1403   Sat Mar 14 22:53:12 2009 KakeruUpdateoplevsarm cavity oplev calibration
I finished a calibration of optical levers.

To calibrate oplevs, I locked appropriate cavity and tilted a mirror.
A cavity with tilted mirror decrease its arm power. So I can know how much the tilt is.
For calibration of ITMX and ETMX, I locked X arm and measured TRX.
For ETMX, ETMY and BS, I locked Y arm and measured TRY
For PRM, I locked PRC and measured SPOB
For SRM, I locked SRC and measured REFL166

I used, for example, C1:SUS-ITMX_OPLEV_PERROR as an oplev signal.

The calibration factors for each mirror is below. The attachment is figures of my fitting.
I used modified equation for ITM calibration from my last calibration, so the value become small around 30%.

ITMX Pitch: 142   microrad/counts
ITMX Yaw:   145   microrad/counts
ITMY Pitch: 257   microrad/counts
ITMY Yaw:   206   microrad/counts

ETMX Pitch: 318   microrad/counts
ETMX Yaw:   291   microrad/counts
ETMY Pitch: 309   microrad/counts
ETMY Yaw:   299   microrad/counts

BS Pitch:    70.9 microrad/counts
BS Yaw:      96.3 microrad/counts

PRM Pitch:   78.5 microrad/counts
PRM Yaw:     79.9 microrad/counts

SRM Pitch:  191   microrad/counts
SRM Yaw:    146   microrad/counts


It looks strange that ITMY, BS and SRM has different value. I think this is a fitting problem.
These data have some asymmetry and cause these 20%-30% difference.
Actually, PRM Yaw has a little asymmetry but the value doesn't differ from Pitch.
This means that this calibration factor potentially has below 30% error.
(These data are the most fine data. I think we must adjust Y arm yaw alignment. The beam spot of ETMY looks too low!)
For SRM, I couldn't get fine data because it was very sensitive to tilt and easily lose its lock.
When I tuned cavity enough, The data become almost flat, so I used detuned cavity.

It is also strange that ITMX and ITMY is different. I guess that this is caused by the difference of the QPD input. The sum of QPD is around 10000 for ITMX and around 4500 for ITMY.
The difference between BS or PRM and SRM is same, I guess. The sum of QPD input for BS and SRM is around 1500, but for SRM, it is around 10000.

I will write more detailed document and upload it with my calibration code.
Attachment 1: oplev.pdf
oplev.pdf oplev.pdf oplev.pdf
  1404   Sun Mar 15 21:50:29 2009 Kakeru, Kiwamu, OsamuUpdateComputersSome computers are rebooted

We found c1lsc, c1iscex, c1iscey, c1susvme, c1asc and c1sosvme are dead.
We  turned off all watchdogs and turned off all lock of suspensions.
Then, I tried to reboot these machines from terminal, but I couldn't login to all of these machines.

So, we turned off and on key switches of these machines physically, and login to them to run startup scripts.

Then we turned on all watchdogs and restored all IFO.

Now they look like they are working fine.
 

  1411   Fri Mar 20 11:01:02 2009 steveUpdatePEMparticle counts are high

The outside particle counts for 0.5 micron are 3 million this morning at 9am. Low clouds, foggy condition with low inversion layer.

This makes the 40m lab 30-50K

I just turned on the HEPA filter at the PSL enclosure.

Please, leave it on high

 

Attachment 1: particles32d.jpg
particles32d.jpg
  1413   Fri Mar 20 15:37:58 2009 KakeruUpdateoplevsarm cavity oplev calibration

I calibrated several oplevs with OSEM signal as a confirmation of my fitting method the method is:

1) I tilted mirrors and get signals from oplevs (C1:SUS-XXXX_OPLEV_PERROR) and OSEM (C1:SUS-XXXX_SUS{PIT/YAW}_IN1).
2) I compared amplitudes of two signals and calculated conversion factors.
3) I calibrated factors above to microrad/counts with
i) The calibration factor of OSEM (2 V/mm)
ii) The calibration factor from count to V of OSEM; 1/16384 V/counts
iii) The shape of whitening filter of OSEM: 30, 100:3 (these values is taken from http://www.ldas-sw.ligo.caltech.edu/ilog/pub/ilog.cgi?group=40m&task=view&date_to_view=04/07/2005&anchor_to_scroll_to=2005:04:07:20:28:36-rana).
iv) The size of mirrors; 125mm for large optics and 75.5mm for small optics.


This calibration has some uncirtainties.

1) The calibration factor of OSEM looks very rough.
2) Output matrixes looks not to be normalized. It looks vary from 0.5 to 1.5 .
3) I don't know where OSEMs are put on mirrors accurately.

So, this calibration is very rough and may have uncertnty of a few factors, I could confirm my fitting calibration in orders.

From this calibration, I got calibration factors listed below.

ITMY Pit: 76 microrad/counts (257 microrad/counts with fitting method)
ITMY Yaw: 58 microrad/counts (206 microrad/counts)
BS Pit : 27 microrad/counts (70.9 microrad/counts)
PRM Yaw : 22 microrad/counts (79.9 microrad/counts)

For the other mirrors, OSEM outputs matrixes are not optimized and I couldn't get fine signals (I think this is not good!).

Each value is smaller than the value calibrated with fitting method in factor 3-4. There looks to be some systematic error, so there must be some difference in parameters used in OSEM calibration.
  1416   Sun Mar 22 22:47:58 2009 ranaUpdateDMFseisBLRMS compiled but still dying
Looks like seisBLRMS was restarted ~1 AM Friday morning but only lasted for 5 hours. I just restarted it on megatron;
let's see how it does. I'm not optimistic.
  1419   Tue Mar 24 03:05:25 2009 YoichiUpdateLockingLocking tonight
MC1 issue:
The MC1 seems to be drifting still. I found it was off from the SUS drift-mon reference values and restored the alignment using the SUS drift-mon before I went home for dinner.
But when I came back being happy with the Japanese victory over S-Korea at the WBC final, the MC was unhappy again.
I restored the alignment of the MC1 using the SUS drift-mon once again and centered the WFS QPDs.
I will leave the MC unlocked again tonight to see the drift. You are welcome to lock the MC in the morning as I will have corrected enough data by the time people come in.

Computer overloads:
I removed some filters from suspensions to off load susvme computers.
Nonetheless, both susvme1 and susvme2 are still over loaded during the dither alignment. The alignment results are in general ok. So this is not a too serious problem.
But still it would be nice to resolve.

3.8kHz hunting:
I made several measurements of the AO path loop gains (using the SR785) and the transfer functions from the CARM excitation (actuation to the ETMs) to the PO_DC signal as the arm powers are increased.
There is a similar structure as in the AO loop found also in the CARM->PO_DC transfer functions. This implies that the problem is likely to be in the PO_DC sensor not in the MC->VCO actuator. But the MC and the VCO could still be the
cause of the problem because they were in the control loop when the CARM->PO_DC TF were measured.
The peak frequency does not seem to depend on the arm power, but the conclusion is not definite because I was only able to measure the TFs from arm power 5 to 10 (not much difference).
I will make plots and post them later.

To Do for tomorrow:
Tonight the CARM error signal was noisier than the reference spectra (broad band white noise appeared). I should check the beam centering of the SPOB PD.
Also someone should center the oplevs of the mirrors as some of them are off.
Continue to measure the TFs at various power levels.
Try to put another (Thorlabs?) PD at the POB port to get PO_DC from it.
  1420   Tue Mar 24 09:04:02 2009 steveUpdateSUS4.8 mag earthquake

SRM, ITMX, ETMX, ITMY and ETMY lost damping at 4:55am this morning from 4.8 magnitude earthquake.

Their damping were restored.

C1:SUS-ITMX_URSEN_OUTPUT swich was found in off position. It was turned on.

MZehnder  and MC were locked.

The WFS qpd spot needs recentering

  1422   Tue Mar 24 13:54:49 2009 JenneUpdateSUSOp Levs Centered

ITMX, ITMY, BS, SRM, PRM op levs were all recentered.  ETM's looked okay enough to leave as-is. 

  1423   Tue Mar 24 19:55:24 2009 JenneUpdateLSCNew PO DC

[Rana, Jamie, Jenne]

SPOB DC hasn't been so good lately, so we installed a new PO DC PD on the PO table.  We used a 30% reflecting beam splitter (BS1-1064-30-1025-someotherstuff).  We didn't check with a power meter that it's a 30% BS, but it seems like that's about right.  The beamsplitter is as close as we could get to the shutter immediately in front of the regular POB/SPOB PD's, since that's where the beam gets narrow.   The new picked-off-pickoff beam goes to a Thorlabs 100A PD.  We haven't yet checked for reflected beams off the PD,  but there is a spare razor blade beam dump on the table which can be used for this purpose.  The output of this PD goes to the LSC rack via a BNC cable.  (This BNC cable was appropriated from it's previous "use" connecting a photodiode from the AP table to a bit of air just next to the LSC rack.)  Our new cable is now connected where the old SPOB DC cable used to be, at the input of a crazy Pomona Box tee.

For reference, the new levels of POB DC and SPOB DC, as measured by their BNC DC out connections is ~4mV each.  Since the beamsplitter is 70% transmissive, we used to be getting about 5.7mV on each PD.

The new photodiode puts out about 40mV, but it has an ND1.0 filter on, so if more gain is needed, we can take it off to get more volts.

 

  1424   Tue Mar 24 23:23:05 2009 ranaUpdateLSCNew PO DC
We also found that the SPOB RF cable was going through a splitter before going into the SPOB demod board. The other
input of the splitter was open (not terminated). Using 50m Ohm devices without terminated inputs is illegal. It
makes there be standing waves in the cables and makes the RF phase very dependent on cable lengths. We took away
the splitter and ran the cable straight. So expect some change in the SPOB gain and phase plus some shame.
  1426   Wed Mar 25 04:18:28 2009 YoichiUpdateLockingTuesday Locking
After the new PO_DC PD was installed, I tweaked several gains to make the locking scripts work right.
First of all, I increased the gain of PD12 (PD12_I is SPOB) by a factor of 1.4 to compensate for the power decrease
by the insertion of the BS. SPOB is used by the PRM alignment script. I was too lazy to modify the scripts.

Then I optimized the SRC DD signal which is taken from the POB.

I also had to do some gain adjustments for the CARM loop.

The attachment (AO path open loop TF) shows a depressing fact that the 3.8kHz peak is still there with the new PO_DC PD. So it was not a problem of the SPOB PD.
Next, I will check the cross over frequencies of the PZT and PC paths in the FSS and the VCO/MCL cross over.
Attachment 1: AO-Loop-p9.png
AO-Loop-p9.png
  1427   Wed Mar 25 09:55:45 2009 steveUpdateIOOglitching sensors of MC

SUS-MC1_SENSOR_SIDE and SUS-MC2_SENSOR_UL are glitching

Yesterday's 4.8mag earthquake at Salton Sea is shown on Channel 1

Attachment 1: glitchesofMC.jpg
glitchesofMC.jpg
  1428   Wed Mar 25 17:22:58 2009 YoichiUpdateIOOMC lock without FSS
I made 40k:4k passive filter in a POMONA box and connected it to IN1 (not TEST IN1) of the FSS box.
With this modification and cut-and-tries with the gain sliders, I was able to lock the MC with 80kHz bandwidth by feeding back directory to the laser frequency.
The attached figure shows the open loop transfer function.
The phase margin is thin at 80kHz. Because of this, I could not turn on the MC super boost filters.
But I believe that we can increase the gain further by modifying the filter shape.

I used the following settings:
[MC Board]
C1:IOO-MC_REFL_GAIN 14
C1:IOO-MC_REFL_OFFSET -4.2381
C1:IOO-MC_BOOST1 0   (You can turn it on if you want, but turn it off for locking)
C1:IOO-MC_BOOST2 0
C1:IOO-MC_POL 1   (Minus)
C1:IOO-MC_VCO_GAIN 4
C1:IOO-MC_LIMITER 1 (Disable)

[FSS box]
C1:PSL-FSS_SW1 0 (Test1 ON)
C1:PSL-FSS_INOFFSET 0.1467
C1:PSL-FSS_MGAIN 30
C1:PSL-FSS_FASTGAIN 14 (Do not increase it, at least while locking. Otherwise the phase lag from the PZT loop gets significant and the MC loop will be conditionally stable).
I also turned down the FSS slow servo's RC transmission threshold to zero so that the slow servo works even without the RC locked.
Attachment 1: MC-loop-gain.png
MC-loop-gain.png
  1429   Wed Mar 25 20:41:43 2009 JenneUpdateIOOMode Cleaner Servo Board Transfer Functions (to be updated)

When all things fail (netgpibdata.py is giving me weird data.  When I plot the data it has saved from the 4395A, it's some wierd other universe's version of my transfer function.  I don't really know what's up.  I'm pretty sure I'm getting the 'correct' data, since each TF looks vaguely like it should, but with some crazy humps.  I'll talk to Yoichi in the morning about it maybe.) (also, we're low on emergeny floppy discs), you can always take a picture of the Agilent 4395's screen, as shown below.

* Mode cleaner and PMC are both relocked after my shenanigans, and I'll try again in the morning (I assume locking is going on tonight) to get real TF's with real data, as opposed to the photo method.

Note to self:  post the data of the TFs in the elog along with the plots, for posterity.

 

These TFs are of the Mode Cleaner servo board, exciting IN1 (or the 3.7MHz notch pomona box which is connected to IN1), and measuring at the SERVO out of the board.

One with the box, one without the box, and one of just the box for good measure.

Attachment 1: MCwithBoxsmall.JPG
MCwithBoxsmall.JPG
Attachment 2: MCnoBoxsmall.JPG
MCnoBoxsmall.JPG
Attachment 3: PomonaBoxforMCsmall.JPG
PomonaBoxforMCsmall.JPG
  1430   Thu Mar 26 00:45:24 2009 JenneUpdateIOOMode Cleaner Servo Board Transfer Functions (to be updated)

Quote:

netgpibdata.py is giving me weird data.  When I plot the data it has saved from the 4395A, it's some wierd other universe's version of my transfer function.  I don't really know what's up. 

 Yoichi, in all his infinite wisdom, reminded me that the netgpibdata script saves the data as the REAL and IMAGINARY parts, not the Mag and Phase.  Brilliant.   Using that nugget of information, here are the TFs that I measured earlier:

The last attachment is the .dat and .par files which contain the data and measurement parameters for the 3 TFs in the plots.

Attachment 1: MCwithandwithoutfilter25Mar2009.png
MCwithandwithoutfilter25Mar2009.png
Attachment 2: PomonaBoxMCfilter25Mar2009.png
PomonaBoxMCfilter25Mar2009.png
Attachment 3: MCServoData25Mar2009.tar.gz
  1431   Thu Mar 26 04:01:24 2009 YoichiUpdatePSLFSS Open Loop Gain
Yoichi, Peter, Jenne

Attached is the open loop transfer function of the FSS as of today with the common gain = 12dB and the fast gain = 16dB.
The UGF is only 250kHz. If we increase the common gain, the PC goes crazy. Exactly the same symptom as before I fixed the oscillating op-amp.

I wanted to check the cross over frequency but there is no excitation point in the fast path nor PC path. Therefore, it is not easy.
Attachment 1: OpenLoopTF.png
OpenLoopTF.png
  1432   Thu Mar 26 04:09:38 2009 YoichiUpdateIOOSingle X arm lock spectra with different MC lock schemes
The attached plots show MC_F, FSS_FAST_F and XARM IN/OUT spectra with different MC locking modes.
The conventional locking means the FSS is used. The direct frequency lock is the new way.
You can see that at low frequencies, the frequency actuator is working hard to suppress the MC pendulum motions.
The X-arm also sees a lot of frequency noise at low frequencies because of this.
The transmitted power of the X-arm fluctuates a lot making it difficult to align the mirrors.

The zoomed plots show that the structures in the kHz band are also present in the case of the direct frequency lock, although the frequencies are somewhat different.
Attachment 1: XarmSpectra.pdf
XarmSpectra.pdf
Attachment 2: XarmSpectraZoom.pdf
XarmSpectraZoom.pdf
  1433   Thu Mar 26 04:27:26 2009 YoichiUpdateLocking3.8kHz peak as a function of the arm power
During the power ramp-up, I actuated CARM using ETMs and measured the transfer functions to the PO_DC at several arm powers.
The peak grows rapidly with the power. It also seems like the frequency shifts slightly as the power goes up, but not much.

Some sort of an RSE peak ? An offset in the PRC lock point ?
Attachment 1: CARM-PODC.pdf
CARM-PODC.pdf
  1434   Thu Mar 26 09:08:18 2009 KakeruUpdateoplevsarm cavity oplev calibration
I uploaded a document about my oplev calibration.
/cvs/cds/caltech/users/kakeru/oplev_calibration/oplev.pdf

At same place I put my matlab codes for calibration.
/cvs/cds/caltech/users/kakeru/oplev_calibration/oplev_calibration.m
  1436   Fri Mar 27 02:50:54 2009 YoichiUpdateLockingDD demodulation phase suspicious
I noticed that the gain of PD6_Q (before the phase rotation) was 0 whereas PD6_I gain was 15.
This means the demodulation phase of the PD6 had no meaning other than changing the gain.
According to the conlog, it has been zero since March 2nd. I don't know how it happened.

While I was re-adjusting the DD phase, the MC started to unlock frequently (every 10 minutes or so).
MC1 is again drifting a lot (it is getting step-function like alignment changes intermittently).
This practically made it impossible to work on locking. So I decided to fix the MC first.
See Peter's elog entry for the MC work.
  1437   Fri Mar 27 15:05:42 2009 YoichiUpdateIOOMC glitch investigation
Attached plots are the result of the MC1 trend measurement.
See the attachment #1. The first two plots show the drift of the MC1 alignment as seen by the OSEMs. It is terrible. Other MC mirrors also drifted but the scale is smaller than the MC1.
From the VMon channels, you can see that the control voltages were quiet.
 
The monitor channels we added were:
 
MC_TMP1 = UL coil bias. Input to the coil driver board.
MC_DRUM1 = UL coil bias. Output of the current buffer.
OSA_APTEMP = LR coil bias. Input to the coil driver board.
OSA_SPTEMP = LR coil bias. Output of the current buffer.
 
The bias voltages show no drift except for a glitch around 7AM. This glitch did not show up in the SPTEMP channel (LR coil bias output). This was because the probe was connected to the coil side of the output resistor by mistake.
 
The second attachment shows a zoomed plot of MC1 OSEM signals along with the bias monitor channels (signals were appropriately scaled so that they all fit in +/-1).
There is no correlation between the OSEM signals and the bias voltages.
 
Since we were only monitoring UL and LR coils, I changed the monitor points as follows.
 
MC_TMP1 = LL coil bias. Output of the current buffer.
MC_DRUM1 = UL coil bias. Output of the current buffer.
OSA_APTEMP = UR coil bias. Output of the current buffer.
OSA_SPTEMP = LR coil bias. Output of the current buffer.
 
I will leave the MC unlocked for a while.

Quote:

Yoichi, Pete

The MC loses lock due to glitches in the MC1 coils. 
We do not know which coil for sure, and we do not know if it is a problem going into the board, or a problem on the board. 
We suspect either the UL or LR coil bias circuits (Pete would bet on UL).  If you look at the bottom 4 plots in the attached file, you can see a relatively large 3 minute dip in the UL OSEM output, with a corresponding bump in the LR (and smaller dips in the other diagonal).  
These bumps do not show up in the VMONS which is why we are suspicious of the bias.
To test we are monitoring 4 points in test channels, for UL and UR, both going into the bias driver circuit, and coming out of the current buffer before going into the coils. 
 

We ran cable from the suspension rack to the IOO rack to record the signals with DAQ channels.

The test channels:

UL coil      C1:IOO-MC_DRUM1  (Caryn was using, we will replace when we are done)

UL input   C1:IOO-MC_TMP1 (Caryn was using, we will replace when we are done)

LR coil      C1:PEM-OSA_SPTEMP

LR input   C1:PEM-OSA_APTEMP

We will leave these overnight; we intend to remove them tomorrow or Monday.

We closed the PSL shutter and killed the MC autolocker.

 

Attachment 1: MC1_Drift.pdf
MC1_Drift.pdf
Attachment 2: MC2_Drift.pdf
MC2_Drift.pdf
  1438   Fri Mar 27 17:52:16 2009 YoichiUpdateIOOMC glitch investigation
Per Rob's suggestion, I put the probes across the output resistors of the bias current buffers instead of measuring the output voltage with respect to the ground.
This way, we can measure the current flowing the resistor. The change was made around 17:30.

Quote:
Attached plots are the result of the MC1 trend measurement.
See the attachment #1. The first two plots show the drift of the MC1 alignment as seen by the OSEMs. It is terrible. Other MC mirrors also drifted but the scale is smaller than the MC1.
From the VMon channels, you can see that the control voltages were quiet.
 
The monitor channels we added were:
 
MC_TMP1 = UL coil bias. Input to the coil driver board.
MC_DRUM1 = UL coil bias. Output of the current buffer.
OSA_APTEMP = LR coil bias. Input to the coil driver board.
OSA_SPTEMP = LR coil bias. Output of the current buffer.
 
The bias voltages show no drift except for a glitch around 7AM. This glitch did not show up in the SPTEMP channel (LR coil bias output). This was because the probe was connected to the coil side of the output resistor by mistake.
 
The second attachment shows a zoomed plot of MC1 OSEM signals along with the bias monitor channels (signals were appropriately scaled so that they all fit in +/-1).
There is no correlation between the OSEM signals and the bias voltages.
 
Since we were only monitoring UL and LR coils, I changed the monitor points as follows.
 
MC_TMP1 = LL coil bias. Output of the current buffer.
MC_DRUM1 = UL coil bias. Output of the current buffer.
OSA_APTEMP = UR coil bias. Output of the current buffer.
OSA_SPTEMP = LR coil bias. Output of the current buffer.
 
I will leave the MC unlocked for a while.

 

 

 

  1439   Sun Mar 29 13:44:27 2009 steveUpdateSUSETMY sus damping restored

ETMY sus damping was found to be tripped.

It was retored.

All fluorecent light were turned off. Please try to conserve some energy.

  1440   Sun Mar 29 17:54:41 2009 YoichiUpdateSUSMC1 drift investigation continued
The attached plots show the trend of the MC OSEM signals along with the voltages across the output resistors of the bias current buffers.
The channel assignments are:
MC_TMP1 = LL coil
MC_DRUM1 = UL coil
OSA_APTEMP = UR coil
OSA_SPTEMP = LR coil

Although the amplitude of the drift of MC1 is much larger than that of MC2 and MC3, the shape of the drift looks like a daily cycle (temperature ?).
This time, I reduced the MC1 bias currents to avoid saturation of the ADCs for the channels measuring the voltages across the output resistors.
This may be the reason the MC1 has been non-glitchy for the last day.

OSA_APTEMP (UR Coil) shows a step function like behavior, although it did not show up in the OSEM signals.
This, of course, should not happen.

Today, I went to the MC1 satellite box and found that the 64-pin IDE like connector was broken.
The connector is supposed to sandwich the ribbon cable, but the top piece was loose.
The connector is on the cable connecting the satellite box and the SUS rack.
I replaced the broken connector with a new one. I also swapped the MC1 and MC3 satellite boxes to see if the glitches show up in the MC3.

I restored the bias currents of the MC1 to the original values.

The probes to monitor the voltages across the output resistors are still there. For OSA_SPTEMP, which was saturating the ADC, I put a voltage divider before the ADC. Other channels were very close to saturation but still within the ADC range.

Please leave the MC unlocked at least until the Monday morning.
Also please do not touch the Pomona box hanging in front of the IOO rack. It is the voltage divider. The case is connected to the coil side of the output resistor. If you touch it, the MC1 bias current will change.

Attachment 1: Drift1.pdf
Drift1.pdf
  1441   Mon Mar 30 09:07:22 2009 ranaUpdateSUSMC1 drift investigation continued
Maybe we can temporarily just disconnect the bias and just use the SUS sliders for bias if there's enough range?
ELOG V3.1.3-