40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 277 of 339  Not logged in ELOG logo
ID Date Authorup Type Category Subject
  1112   Tue Nov 4 00:47:53 2008 ranaUpdateASSWiener Filter performance over 5 hours
Same as before, but now with a working Ranger seismometer.

In the spectrogram, the color axis is now in dB. This is a whitened spectrogram, so 0 dB corresponds to
the average (median) subtraction. The color scale is adjusted so that the large transients are saturated
since they're not interesting; from the DV trend its some kind of huge glitch in the middle of the
night that saturated the MC1 accelerometers only (maybe a pump?).

The attached trend shows the 5 hours used in the analysis.
Attachment 1: f2.png
Attachment 2: f.png
  1113   Tue Nov 4 01:03:01 2008 ranaSummaryPEMperiodic thump noise in MC1_ACC
There seems to be a periodic thump seen by the MC1 Accelerometers as well as the surrounding optics.

The first 5 hour minute-trend plot shows the periodic thumping as well as the one large saturating event which ruins the
Wiener noise subtraction.

The second plot is a 30 minute second-trend zoom in.
Attachment 1: Untitled.png
Attachment 2: Untitled2.png
  1119   Thu Nov 6 22:07:56 2008 ranaConfigurationComputersELOG compile on Solaris
From the ELOG web pages:


Martin Huber reports that under Solaris 7 the following command line is needed to compile elog:

gcc -L/usr/lib/ -ldl -lresolv -lm -ldl -lnsl -lsocket elogd.c -o elogd

With some combinations of Solaris servers and client-side browsers there have also been problems with ELOG's keep-alive feature. In such a case you need to add the "-k" flag to the elogd command line to turn keep-alives off.
  1122   Fri Nov 7 15:58:10 2008 ranaUpdatePEMAC is back on
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: mc-acc.pdf
Attachment 2: mc-acc-quad.pdf
  1137   Fri Nov 14 20:35:47 2008 ranaUpdatePSLReference cavity ring down
To make the DEI pulser make a fast pulse on the EO shutter EOMs, we had to make sure:

1) the cable had a high voltage rated dielectric. cheap dielectrics show the 'corona'
effect, especially when there is a bend in the cable.

2) the EO has to have a resistor on it to prevent ringing due to the impedance mismatch.

3) We needed ~3.5 kV to get the EO shutter crystal to flip the light by 90 deg.
  1147   Wed Nov 19 18:02:18 2008 ranaConfigurationElectronicsAll the Marconi Set to the Rubidium Frequency Standard
Not sure what was going on before. I changed the frequency counter to use an AC coupled input, and had it average
for 50 seconds. The output now agrees with the Marconi front panel to less than 1 Hz. Its still not 0.000 Hz,
but not bad.
  1148   Wed Nov 19 18:12:35 2008 ranaConfigurationIOOnew channel for MC drum modes
I set up the lockin to take the MC Demod Board's Qmon signal, demodulate it at 27.5 kHz, and
put the output into a DAQ channel (I think its either MC_DRUM1 or MC1_TEMPS). However,
the MC_DRUM channel doesn't look like its getting anything in the DTT although it looked fine
on a scope. I used the 'sensitivity' setting of the lockin to make the demodulated signal
large enough but not so large that it would saturate the ADC (+/- 2V).
  1150   Fri Nov 21 16:03:50 2008 ranaHowToGeneralRecharging Batteries
I found some black & red "Ninja" alkaline AA batteries in the battery charger. This is dangerous. Please
do not put alkaline batteries in there, only Nimh. If you need help with the battery charger you can
come and talk to me or Rob and we can help you out getting started.
  1154   Fri Nov 21 19:47:26 2008 ranaUpdatePEMGuralp noise measurement
and here's the spectra with them connected - from the coherences, it looks like it needs to be rotated by 90 deg.

I'll next rename the channels to fix this so that we get good seismic data over the weekend with the MC.
Attachment 1: a.png
  1156   Fri Nov 21 21:20:24 2008 ranaUpdatePEMGuralp noise measurement
This is the spectra and time series of the Guralp channels along with the Ranger (MC2). Looks like we could reduce the gain
on the ranger. The Guralp channels run into ADC noise around 40 Hz (which is OK). We'll have to look at the weekday trends
to see if they saturate.
Attachment 1: a.png
  1157   Fri Nov 21 21:28:32 2008 ranaSummaryComputersc0daqawg restart
A few minutes after restarting fb0 for the Guralp channels, the DAQAWG lights went red on the DAQ screens.
Why?? I chose revival procedure #3 for c0daqawg from the Wiki and it came back in a couple minutes.
  1159   Mon Nov 24 16:43:34 2008 ranaConfigurationComputersAlex and Jay took away some computers from the racks
I was over at Wilson house and saw Jay and Alex bring in 3 rackmount computers. One was a Sun 4600 and
then there were 2 3U black boxes. I got the impression that these were the data concentrators or
data collectors or framebuilder test boxes. They said that they got these from the 40m and no one was
in the lab to oppose them except for Bob and he didn't put up much of a fight.

Everything looks green on the DAQ Detail and RFM network screens so perhaps everything is OK. Beware.
  1160   Mon Nov 24 17:14:44 2008 ranaUpdatePSLMach Zender trends
It looks like the MZ has gotten less drifty after the alignment on Friday.
Attachment 1: Untitled.png
  1164   Thu Nov 27 22:56:42 2008 ranaConfigurationEnvironmenttemperature
Attachment 1: mc.png
  1167   Tue Dec 2 19:18:10 2008 ranaSummaryPEMRanger SS-1
In entry http://dziban.ligo.caltech.edu:40/40m/881 and a follow up from Jenne I put in the Ranger calibration.
Since then, we've reduced the SR560 gain from 200 to 100 so the calibration factor is now:

1e-9 (m/s)/count and then 2 poles at 0 Hz, and a Q~1 zero pair at 1 Hz.
in DTT:
G = 1e-9
p = 0, 0
z = 0.7 0.7
  1168   Tue Dec 2 19:51:32 2008 ranaUpdatePEMhalf-micron particle count is alarming
The 0.5 micron dust monitor count is now pretty high (36000). I wandered around the lab to see if there was anything
nasty going on but I didn't see or smell anything in particular. Since today Alberto was sitting around where the
dust monitor is while aligning the PSL beam, we should blame him. Its either garlic, cologne, or time to bathe.

The 400 day hour trend shows that while the counts are not so unusual, the 40m is dirtier than it was last year.
Attachment 1: Untitled.png
Attachment 2: dust.png
  1171   Wed Dec 3 19:21:09 2008 ranaConfigurationPEMRanger move
I looked at the Ranger signals. Somehow it has a relative transfer function of 'f' between it and the Guralp.
i.e.  ------ ~ f

which is strange since according to their manuals, they should both be giving us a voltage output which is proportional
to velocity. I checked that the Ranger only has a load resistor and then an SR560 low pass at 300 Hz. Jenne assures
me that the Guralp breakout box shouldn't have any poles either (to be double checked). Its a mystery.

We made sure that the SR560 now is DC coupled, G = 100, & 1-pole low pass at 300 Hz. I moved it over next to the Guralp
(went through the mass recentering procedure after forgetting to lock it before moving). It is behaving as it was

Attached is a 2 page PDF of the comparisons. The 'MC1' channels are Guralp and 'MC2' is Ranger.

The second attachment compares our seismometers (in counts) with the LHO Guralp seismometers. There's no high frequency
rolloff there like what we see here so I bet a dollar that there's a pole in the Guralp box somewhere.
Attachment 1: c.pdf
c.pdf c.pdf
Attachment 2: wsnb.pdf
  1179   Fri Dec 5 09:29:59 2008 ranaUpdateIOOdrum modes observable without excitation
Not sure what the y-scale is since there aren't any y axis labels in the plot, but it seems like we
now get an SNR of a ~few with a BW of 0.1 Hz. IN principle, the frequency noise out of the PSL ought
to be limited by the VCO phase noise at these frequencies (sort of) so the broadband MC_F level
is very roughly equal to 20-100 mHz/rHz.

Since dnu = dL*(c/lambda)/L_MC, the thermal peaks have a height of ~10^-15 m_RMS. We (Caryn) should check
that these numbers are true and then see if this is the correct amount of energy for thermally excited
mirror modes.
  1180   Fri Dec 5 14:13:41 2008 ranaSummaryIOOMC trend for the last 4 days
The MC has stayed locked for ~3 days! I just broke it to reset the MZ.
Attachment 1: g.png
  1183   Sun Dec 7 16:02:46 2008 ranaUpdateGeneralMag 5.1 EQ halfway to Vegas
There was a Mag 5.1 EQ Friday night at 8:18 PM.

It tripped most of our optics. They all damped down passively except for MC2. Further more, ITMY seems to have come back to a different place.

Don't know why MC2 was so upset but I think maybe its watchdog didn't work correctly and the side loop is unstable when there are
large motions. After I lowered the side gain by 10x and waited a few minutes it came back OK and the MC locked fine.

I have just now put all the WDs into the Shutdown state so that we can collect some hours of free swinging data to see if there's been
any damage. Feel free to redamp the optics whenever you need them. Someone should do the eigenfrequency check in the morning and compare
with our table of frequencies in the wiki.

I excited the optics using the standard SUS/freeswing-all.csh script. Here's the output:
Excited all optics
Sun Dec  7 16:07:32 PST 2008
Attachment 1: g.png
Attachment 2: Untitled.png
  1184   Sun Dec 7 16:12:53 2008 ranaUpdateDAQbooted awg
because it was red
  1213   Fri Jan 2 17:20:44 2009 ranaSummaryComputer Scripts / Programs40m GWINC
I have made a '40m' directory in the iscmodeling CVS tree which allows one to run a 40m version of GWINC.

As does the previous one, it takes the default advLIGO config file and modifies some of the struct parameters
to make it appropriate for the 40m.

To make it run, I have added susp1.m to the GWINC directory. This calculates suspension thermal noise using
the Gonzalez-Saulson method that was later extended to
mirrors by Y. Levin. This is also the code used in the LIGO Noise Budget at the sites.

The previous code was giving a much larger value for thermal noise (probably because I didn't understand how
to use it right). It was based on a SURF report from '99.

Since we will have a mixture of MOSs and SOSs in the arms, I have just used SOSs in the model. So the suspension
thermal noise is overestimated by ~sqrt(2) (and realistically its uncertain by a much larger factor).

Since the new code now uses GWINC, the mirror and coating thermal noise are now more correct and use the
coherent therm-optic noise picture.

The 2 page PDF file shows the noise for 0 deg and 90 deg tuning of the SRC.

Although it looks like, from this plot, that we could measure coating thermal noise at the 40m, in reality we would have
to fix all of the technical noise sources first. Just the coil driver noise is probably at the level of 3 x 10^-17 m/rHz
at 100 Hz.
Attachment 1: bench40.pdf
bench40.pdf bench40.pdf
  1217   Thu Jan 8 16:49:37 2009 ranaConfigurationloreHP 5550dtn (Grazia) set up on allegra

I set up printing to grazia from allegra. The CUPS interface was not as straightforward as Tobin had made it seem in the Wiki. I had to type in the IP address and port number by hand.

The steps (AFAIR):
1) Goto http://localhost:631/
2) Click on "Add Printer"
3) Choose HP JetDirect
4) Use the correct address (socket://
5) Choose HP and the 5550 postscript driver as the options
6) Try to only print useful stuff and not kill too many trees.

It ought to be root to do that.
  1230   Thu Jan 15 22:30:32 2009 ranaConfigurationDMFDMF start script
I tried to restart the DMF using the start_all script: http://dziban.ligo.caltech.edu:40/40m/280

it didn't work Frown
  1239   Mon Jan 19 18:21:41 2009 ranaUpdateComputersloadLIGOData a GUI for mDV
The tool is very nice; I looked at the seismic trend for 16 days (attached).
However, it gives some kind of error when trying to get Hanford or Livingston data.
Attachment 1: a.png
  1242   Wed Jan 21 22:53:08 2009 ranaUpdateLSCAS CCD centering and ASDD demod phase
Just my opinion, but I think all we want out of the DD signals is something to control the DRM
and not be sensitive to the carrier and the CARM offset. So if the handoff can be done so that
the lock point is unchanged from single demod then everything is fine.

A second order concern is how the 133 & 199 MHz signals are mixed in order to minimize the
matrix cross-coupling and the SNR of the diagonal elements.
  1297   Thu Feb 12 14:39:07 2009 ranaSummaryGeneralSilicon Beam Dump test
Yesterday evening, Ken Mailand and I tested the reflectivity of a piece of polished Silicon. Since Silicon has such a high thermalconductivity (compared to stainless and fused silica) and can take much more heat than black glass and should have a very good BRDF and should absorb most of the 1064 nm light if we hit it at Brewster's angle, we want to try it out in the first version high power, low scatterbeam dump. This dump will be a 'V' style dump like what Steve has tested nearly a year ago, but the incoming beam will first hit this piece of Silicon.

The pictures of the setup and the Silicon with the beam hitting it are here.

Brewster's angle for p-pol at 1064 nm is 74.2 deg (n = 3.53 @ 1064 nm). We set up a cube polarizer on the output of the ~1064 nm CrystaLaser. 144 mW got to the Si; the reflected beam was ~1.9-2.0 mW after tuning the angle for minimum power. Via eyeball and protractor it seems that we're at ~74 deg. So the reflectivity is < 1.5-2%. This is good enough; the reflected power will be < 1 W in all cases for eLIGO and that can be absorbed by the rest of the stainless V dump. The 35 W of heat in the silicon will be mostly gotten rid of through conduction into the attached heat sink fins.

This kind of dump would go into places like the PMC-REFL, MC-REFL, & IFO-REFL, where we occasionally need to take high power, but also are sensitive to backscatter.
  1307   Mon Feb 16 00:43:46 2009 ranaUpdateComputersmedm directory wiped on nodus
I accidentally did an 'rm -rf' on the medm directory in nodus, instead of on my laptop as was intended.

I then did an svn checkout. So everything should be current as of the last update, but I am sure that
we have not done a checkin on all of the latest screen enhancements. So...we may have to revert to the
Sunday morning tar to get the latest changes back.
  1312   Mon Feb 16 20:47:48 2009 ranaConfigurationIOOMode Cleaner WFS Loop Gain change
I found the MCWFS gain slider down at 0.012. In this state the UGFs are probably around 10-30 mHz
and so there is no reduction of seismic noise. It is mainly a DC alignment tool in this state.

We often have reduced the loop gain thusly, to prevent the dreaded "MCWFS eating CM loop gain" disease.
That disease is where there are CM loop instabilities at ~5-30 Hz because of loop cross-couplings
who's exact nature has never been understood (TBI).

Today, I implemented a 4th order, 7 Hz low pass (RLP7) into the loops and turned up the gain by a factor
of 30 to 0.3. In this state, the damping time constants seem to be ~0.5-2 seconds as shown in the first
PDF. I didn't have enough patience to do the interminable swept sine measurements down to 0.1 Hz.

The second PDF shows the Bode plot of the RLP7 filter compared to the pre-existing but unused ELP10.

The third PDF shows my estimate of the OLG TF. This is made by just putting a "Pendulum" filter into the
MCWFS bank and then plotting all the filters together using FOTON. The BLUE curve shows the old TF but
with the new high gain and the RED curve shows the new TF with the new gain.

With this new filter, I bet that we can get away with the higher WFS gain, but if there's any problem during the
handoff, the gain should be reverted to the low value.

In the 4th PDF file, I plot the spectra of 4 of MC2's control signals so that you can see what is bigger than what.
ASCPIT is the one that has the feedback from the WFS's in it. These are all just in units of counts and so to compare
them in some sort of displacement units you have to take into account the pitch moment of inertia, the mirror mass,
and the mis-centering of the beam from the center of rotation of MC2...
Attachment 1: pmc-pzt-cal.pdf
Attachment 2: a.pdf
Attachment 3: olg.pdf
Attachment 4: mc2.pdf
  1315   Mon Feb 16 23:09:52 2009 ranaUpdateElectronicsMC Servo Board offset gone bad!

The attached plot shows that someone broke the MC_SUM_MON channel around 10:30 AM this past Wednesday the 11th. This is the EPICS monitor of the MC error point.

Come forward now with your confession and I promise that I won't let Steve hurt you.

Attachment 1: mcoff.png
  1320   Wed Feb 18 19:13:20 2009 ranaConfigurationComputersSVN & MEDM & old medm files
Allegra had a 2 year old version of SVN installed and CentOS (yum) couldn't upgrade it, so I did an 'svn remove subversion'
and then a 'svn install subversion' to get us up to the Dec '08 version (1.5.5) which is the latest stable.

I also removed all of the old ASS medm directories without backing them up. There's a new RCG script version which is
fixed so that it no longer dumps these old medm directories in there; there's no need since there's already an
medm archive area.

I also removed the medm/old/ directory, did an svn remove, and then copied it back. This is the only way I know of
removing something from the repository without removing it from the working directory.
  1321   Wed Feb 18 21:03:22 2009 ranaUpdateCamerasETMY Camera work not elogged!

The control room video is showing us a false ETMY image. Who worked on the ETMY camera or video today??!!

  1322   Wed Feb 18 21:10:21 2009 ranaUpdateIOOMC Drumhead mode lost again
In early December, Caryn and I noticed that the MC Drumhead mode was visible at the Qmon point of
the MC demod board using a spectrum analyzer and no external excitation of the MC mirrors. We then
started tracking the MC Drumhead modes.

Today I found that it is gone again. It also wasn't there when I looked for it in 2007. Mad

I looked at the MC error point spectrum and it seemed reasonable. Changing the gains in the MZ, ISS, PMC, & FSS
had no good effect on the noise spectrum.

The voltage noise above 10 kHz in the MC error point is increasing like ~f. I think that this means that
the leftover is the noise from the FSS. Below 10 kHz it is the noise of the VCO (10 mHz/rHz).

One possibility is that the high frequency noise changes with the mood of the NPRO. There should be no
frequency noise induced by the decay of the PA diode power. We can do an NPRO SLOW scan to see if there
is some kind of mode hop noise happening.
  1357   Wed Mar 4 23:42:45 2009 ranaConfigurationPSLpsl db change

I made the following change to correct the sign of the 126MON channel:

allegra:c1aux>ezcawrite C1:PSL-126MOPA_126MON.EGUF -410
C1:PSL-126MOPA_126MON.EGUF = -410
allegra:c1aux>ezcawrite C1:PSL-126MOPA_126MON.EGUL 410
C1:PSL-126MOPA_126MON.EGUL = 410

  1360   Thu Mar 5 02:24:19 2009 ranaConfigurationComputersyum.repos.d

I added the following repos which I found on allegra to megatron and then did a 'yum install sshfs' on both machines:

total 28
-rw-r--r-- 1 root root  428 Feb 12 16:47 rpmforge.repo
-rw-r--r-- 1 root root  684 Feb 12 16:47 mirrors-rpmforge
-rw-r--r-- 1 root root 1054 Feb 12 16:47 epel-testing.repo
-rw-r--r-- 1 root root  954 Feb 12 16:47 epel.repo
-rw-r--r-- 1 root root  626 Feb 12 16:47 CentOS-Media.repo
-rw-r--r-- 1 root root 1869 Feb 12 16:47 CentOS-Base.repo
-rw-r--r-- 1 root root  179 Feb 12 16:47 adobe-linux-i386.repo

This also required me to import the rpmforge GPG key:

sudo rpm --import http://dag.wieers.com/rpm/packages/RPM-GPG-KEY.dag.txt

  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.

  1378   Mon Mar 9 19:27:16 2009 ranaConfigurationComputersMove of the CLIO Digital Controls test setup

Because of the network interference we've had from the CLIO system for the past 3-4 days, I asked the guys to remove

the test stand from the 40m lab area. It is now in the 40m control room. Since it needed an ethernet connection to get out

for some reason we've let them hook into GC. Also, instead of using a real timing signal slaved to the GPS, Jay suggested

just skipping it and having the Timing Slave talk to itself by looping back the fiber with the timing signal. Osamu will enter

more details, but this is just to give a status update.

  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
  1383   Wed Mar 11 01:16:40 2009 ranaSummaryIOOrogue trianglewave in the MC Servo offset slider

On Monday evening, I ran this command: trianglewave C1:IOO-MC_REFL_OFFSET 0 4 120 600;ezcawrite C1:IOO-MC_REFL_OFFSET 1.76

which I thought (from the syntax help) would move that offset slider with a period of 120 seconds for 600 seconds. In actuality, the last argument is the

run time in number of periods. So the offset slider has been changing by 8 Vpp for most of the last day. Oops. The attached image shows what effect

this had in the MC transmitted power (not negligible). This would also make the locking pretty difficult.


In the second plot you can see the zoom in view for ~30 minutes. During the first part, the MCWFS are on and there are large fluctuations

in the transmitted power as the WFS offset changes. This implies that the large TEM00 carrier offset we induce with the slider couples into

the WFS signals because of imbalances in the quadrant gains - we need someone to balance the RF gains in the WFS quadrants by injecting

an AM laser signal and adjusting the digital gains.


Since there is still a modulation of the MC RFPD DC with the WFS on, we can use this to optimize the REFL OFFSET slider. The third plot

shows a 8 minute second trend of this. Looks like the slider offset of zero would be pretty good.

Attachment 1: Untitled.png
Attachment 2: Untitled.png
Attachment 3: a.png
  1384   Wed Mar 11 04:33:57 2009 ranaConfigurationComputer Scripts / Programswild ndsproxy tclshexe

The ndsproxy tcl task on nodus was eating up all the CPU and making the elog slow. I killed it and restarted it.

It looks like it hasn't been making a log file since January. Someone who has some skill in decoding the cryptic csh stdout redirection

syntax should look into this (its in target/ndsproxy/)

  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.
  1405   Mon Mar 16 01:20:40 2009 ranaConfigurationIOOMCWFS noise filtered on the SUS-MC
Recently, we noticed that the IOO-WFS system runs at 2048 Hz and sends its signals to the MC SUS
systems which run at 16 kHz. There is no upsampling filter or anti-imaging filter.

So, I've implemented an RLP666 filter as FM1 in the SUS-MCn_ASC(PIT/YAW) filter banks. This is like a 4th order
Cheby low pass with a low Q notch at 2048 Hz to catch the first image.

The attached PNG shows the ASCPIT_OUT signals before and after the filter is implemented. As you can see, the
big aliased spikes are gone. The reason that MC2 is different from MC1/3 is that they have a hardware 28Hz low pass
and MC2 doesn't. So MC2 had a 28 Hz low pass in software already to match the actuation phase between all the MC
mirrors. The apparent power law noise floor from 40-300 Hz in MC2 is not real - just the Hanning window tail.

And yes, it has been this way for several years and none of us noticed. It remains to be seen if this was causing
any noise in the MC coil drivers via slew rate limiting.
Attachment 1: xarm.png
  1415   Sun Mar 22 22:39:24 2009 ranaSummaryLSCCalibration of the ITM and ETM Actuation
I used the following procedure to calibrate the ITMX actuation signal.

Free Swinging Michelson:
- Restore Michelson
- Align Michelson: Minimize AS_DC (PD3_DC_OUT) by tweaking BS alignment.
- Enable Whitening filters for PD1_Q and PD3_DC.
- Run offsets script to get rid of DC and RF offsets.
- Use DTT Triggered Time Series to get time series and measure peak-peak
amplitude of PD1_Q using DTT horizontal cursors. (Templates/Calibration/090322/FreeSwing.xml)

Michelson Sweeps:
- Lock Michelson
- Drive ITMX_LSC_EXC using ITMX-MI-Sweep.xml template.
- (Next time remember to turn on a low pass in the MICH loop so that its an open loop measurement below 50 Hz).
- Fit and so some math.

Arm Sweeps for the ETMs:
- Lock a single arm
- Sweep ITM & ETM.
- Then sweep MC2 and record drive signal from MC board to the VCO driver.
- Compare and contrast.
Attachment 1: free.png
  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.
  1417   Sun Mar 22 23:16:41 2009 ranaDAQComputer Scripts / Programstpman restart
Could get testpoints but couldn't start excitations. Restarted tpman on daqawg. Works now.

Still no log file. Mad
  1418   Mon Mar 23 15:50:44 2009 ranaConfigurationLSCfilters deleted, lsc rebooted

The LSC time had gone too high. I deleted ~20 filters and rebooted. CPU time came down to 50 usec.

The filters all looked like old trash to me, but its possible they were used.

I didn't delete anything from the DARM, CARM, etc. banks but did from the PD and TM filter banks. You can always go back in time by using the


  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.
  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?
  1456   Mon Apr 6 21:50:43 2009 ranaUpdateLSCArm Locking via pushing MC2
Inspired by our 'No Refcav' scheme here, I was inspired to re-explore the idea of locking the
CARM DOF using only feedback to the MC/laser. Last week I got this to work on the single arm and
full IFO at Livingston.
I also estimate the MC noise there.

Today I found the settings to allow X-arm locking here without any feedback to the ETM or ITM:

- Set the LSC Output Matrix to feed the XARM signal to MC2.
- Turn OFF the input of the LSC-ETMX filter bank (this does not disable tickling).
- Turn OFF FM7 (0.1:10) in MC2-MCL.
- Turn ON MC2-LSC with a gain of 0.2 and FM3 FM4 FM5.

That's enough to lock the arm - its pretty stable. This also assumes that the LSC-MC2 bank has its nominal gain of -0.178.

To determine the gain of +0.2 in the MC2-LSC filter bank, I measured the TF from MC2->PD3_I and from ETMX->PD3_I. I adjusted
the gain to be equal at 150 Hz for acquisition and the sign to be opposite to account for the (-) in LSC-MC2. The TF is

After locking, I type a zero into the MC2-MCL filter bank and that shuts off the feedback from the MC servo to MC2. This is
now topologically similar to the standard CM servo configuration.

The second attachment has the trends of this locking. You can see that the MC_F goes off into the weeds, but the MCL signal
does not so much. I think maybe the MC length is drifting a lot - not the arm.

The third attachment shows the spectra.
Attachment 1: mc2-xarm.pdf
Attachment 2: Untitled.png
Attachment 3: nohands.pdf
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