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  40m Log, Page 277 of 341  Not logged in ELOG logo
ID Date Authorup Type Category Subject
  469   Thu May 8 01:50:25 2008 ranaSummaryASCArm Cavity HOM Resonances
Nothing new, but I calculated the frequencies of the first 22 higher order transverse modes and thought I might as well list them here.

To do this I took formula (23) from page 762 of Siegmans book and put it into this form:
         f_fsr
dfmn =   ----- * (m+n) * acos(sqrt(g1*g2))
           pi

and then calculated them from m+n = 1..22 (22 is not a magic number).

I also used the 'mod' function of matlab to calculate the frequency mod FSR so that we would know how far away
from a cavity resonance it is. I took as parameters: Larm = 38.55 m, Ritm = 1e6 m, Retm = 57.1 m. Kirk measured
the arm length some time ago; we need to measure the arm g-factor...maybe we'll put Tobin on this when he comes
by for a visit.

1.1936 (TEM01, TEM10)
2.3871
3.5807
0.8859 (TEM22, TEM13, TEM31)
2.0795
3.2730
0.5782
1.7718
2.9654
0.2706 (TEM55, ...)
1.4641
2.6577
3.8512
1.1564
2.3500
3.5436
0.8488
2.0423
3.2359
0.5411
1.7347
2.9282
  470   Thu May 8 02:06:13 2008 ranaSummaryCOCThermal Lensing in the ITMs and BS may be a problem
The iLIGO interferometers start to see thermal lensing effects with ~2W into the MC, a recycling
gain of ~50, and a beam waist on the ITMs of ~3.5 cm.

At the 40m, the laser power into the MC is 1/2 as much, the recycling gain is 4-5x less, but the
beam on the ITM has a 3 mm waist. So the power in the ITM bulk is 10x less but the power density
is 100x more
. Seems like the induced lens in the ITM bulk might be larger and that if there's
significant absorption on the ITM face (remember our Finesse is 4-5x higher) the beam size in the
arm cavity may also change enough to measure.

Someone (like Andrey) should calculate how much the beam sizes change with absorbed power.
  484   Sun May 18 18:14:30 2008 ranaSummaryComputer Scripts / Programsautlockers and cron
Today I noticed that the MC was unlocked, the MC autolocker was off, the PSL autolocker was off,
and the PSL Slow loop was off.

Reading through .log files and our elog it seems like things have been this way since Tuesday
when Andrey went around rebooting computers to bring things back.

And it looks like the ETMY optical lever is dead.

I restarted the PSL & MC scripts on op340m. I also locked and aligned the X arm to verify that
not everything is broken. The Y Arm is unalignable until we replace the HeNe.
  485   Sun May 18 18:44:48 2008 ranaSummarySUSOptical Lever SUM Trend - 80 days
I used the OL-Trend.xml dataviewer template to make this plot. Looks like the ETMY optical lever
slowly degraded over the last few months and then finally died 10 days ago. Would someone please
replace this laser and tune the lens position to minimize the spot size on the quad?
  486   Sun May 18 18:59:15 2008 ranaConfigurationComputerscron and hosts
I added rosalba to the hosts file for the control room machines (131.215.113.103).

I also removed the updateddb cron from our op440m crontab because it was running at 5 PM
even though I had set it to run at 5:57 AM. If it still runs then, it must be because of
another crontab.
  493   Fri May 23 08:24:24 2008 ranaAoGTreasureYoichi Aso has arrived !
  495   Sun May 25 16:20:27 2008 ranaConfigurationComputersjoinPDF
I have installed joinPDF 2.1 on rosalba. Since its written in Java, I didn't have to tinker with it at all to work on a 64-bit machine. Now Caryn can put all of her plots into 1 file.
  496   Sun May 25 19:33:16 2008 ranaUpdateIOOMC Bad after Re-alignment
The MC pointing was off and the transmitted power was down after John and Andrey brought it back after the bootfest.

I tried getting it back on Friday but was unsuccessful. Today, after the Phoenix Landing, I got it back to someplace
reasonable, but it still seems to be far off. I will check with Rob before we recenter and of the QPDs.

I had to move all of the MC SUS and also align the beam using the IOO periscope. The attached PDF shows some trends
over the last 80 days. You can see that the drop in MC TRANS is about the same as the drop in PMC TRANS.
  497   Sun May 25 20:30:25 2008 ranaSummaryPSLPMC Mode Matching
I checked the PMC mode matching by ramping the gain down to -10 dB (from +20 dB) and
moving the DC offset around until it caught lock on the different HOMs. Then I recorded
the output power (PMCTRANSPD). The DC offset on this EPICS channel was -0.013 V, so I
used its AOFF field to zero this out. Here is a list of the power in the largest modes:
Mode    Power (V)
----    ---------
00        2.7
10        0.2
04        0.04
02        0.02
BE        0.36      **Bull's Eye mode is TEM02 + TEM20. This can be fixed by lens adjustment.


N.B. To make a PNG file with DTT, just make an EPS file -- then use the eps2png perl script.
  499   Sun May 25 22:33:00 2008 ranaUpdateSUSETMY Oplev Work
I found the ETMY table in disarray and put the panels back on and put the ETMY OL laser back on the quad.

The next thing to do is clean up the table (there's a lot of junk on it) and then put in a lens within
6" of the laser to focus the beam on the quad (no metal diving boards and the lens should be either
uncoated (from our Edmunds collection) or a red lens, not 1064).

Then we have to put the beam cover back on between the viewport and the table.
  509   Sun Jun 1 19:25:10 2008 ranaConfigurationComputersnew monitor on op440m
I installed the new 24" flat screen on op440m. I increased the screen resolution from 1280x1024 to 1900x1200 using
the obscure 'fbconfig' command. You can type Google it if you want.

The old monitor is on the surplus cart. If you are reading this and think you might walk from the 40 over to
Bridge, please wheel the cart full of old computer equipment (on the north side of the control room) over to Larry.

I also copied over all the images on the D40 to a folder on Kirk's computer and deleted the originals.

Dan Busby also visited us last week to help us move the drill press from the Y arm down into the sub basement
of W Bridge.
  544   Wed Jun 18 18:50:09 2008 ranaUpdateComputersIt can only be attributable to human error. (HAL - 2001)
There has been another one of "those" events and all of the front end machines are down.

We poked around and Rob determined that the FEs can't get the EPICS data from EPICS. The
dcuepics machine is hooked up and running and all of the epics binaries are running. We also
tried resetting its RFM switch as well as power cycling the box using the "poweroff" command.


Not a sausage.

Rob points out that although the Signal Detect lights are on on the cards, the 'Own Data' light
is not on on the dcuepics' card although it is on for some of the cards on the other boxes.


We have placed messages with the Russian. If anyone sees him, don't let him go without fixing things.
Also, make sure to follow him around with notepad and possibly a camera to record what it is that
he does. If he's muttering, maybe try to use a sensitive hidden sound recorder.
  546   Thu Jun 19 20:22:03 2008 ranaUpdateGeneralFE Computer Status
I called Rolf (@LLO) who called Alex (@MIT) who suggested that we power cycle every crate
with an RFM connection as we did before (twice in the past year).

Rob and I followed Yoichi around the lab as he turned off and on everything. There
was no special order; he started at the Y-end and worked his way into the corner and
finishing at the X-End. Along the way we also reset the 2 RFM switches around fb0.

This cured the EPICS problem; the FEs could now boot and received the EPICS data.

However, there are still some residual channel hopping-ish issues which Rob and Yoichi are
now working on.
  547   Fri Jun 20 01:38:55 2008 ranaUpdatePEM20 day Weather
Yoichi showed me that its possible to make PNG images from PS using GS:
gs -sDEVICE=png16m -sOutputFile=foo.png bar.ps
  552   Mon Jun 23 15:22:04 2008 ranaBureaucracySAFETYLaser Safety Walkthrough today
  560   Tue Jun 24 22:43:23 2008 ranaSummarySEIStack TF
  570   Thu Jun 26 01:08:22 2008 ranaConfigurationGeneralAlarm Handler Revived
I have revived the Alarm Handler by turning it on on op540m and adjusting the levels of
several of the alarming channels to not alarm (like laser power). The alarm levels are now
set to something reasonable and people should start actually paying attention to them.

I also removed the EO Shutter and Stacis alarm stuff since we don't use them.

To really get in and edit it, you have to close the Alarm Handler and edit the file
in /cvs/cds/caltech/alh/. It allows you to add/subtract useful channels and put in
guidance information.

If the alarm handler beeps about something, don't just close it or silence it, Steve. Just
fix it somehow (either set the threshold better or find the real cause).
  571   Thu Jun 26 01:10:18 2008 ranaUpdatePEMAlarm Handler indicates that dust level is high
In its first useful act, the Alarm Handler started beeping indicating that the dust particle
counts for particles of diameter less than 0.5 micron had exceeded 5000 /cu. ft.
Here's the
80 day trend of particles, temperature and humidity:
  576   Thu Jun 26 18:27:04 2008 ranaUpdateComputer Scripts / ProgramsNo Dataviewer No Cry
Dataviewer was hanging. It would open the Grace window but then not plot anything. Since DTT was working
fine we diagnosed this as a DV only problem. It turned out that there was a boatload of messages in the
dataviewer queue. You can check for extra messaages using the command 'ipcs -q' and then use 'rmq' to remove them.

Dataviewer is working now.

Here's the screen dump from op440m:
op440m:~>ipcs -q
IPC status from <running system> as of Thu Jun 26 18:19:32 PDT 2008
T         ID      KEY        MODE        OWNER    GROUP
Message Queues:
q        400   0x1a51     -Rrw-rw-rw- controls    staff
q          1   0x501      -Rrw-rw-rw- controls    staff
q          2   0x512      -Rrw-rw-rw- controls    staff
q        103   0x553      -Rrw-rw-rw- controls    staff
q          4   0x574      -Rrw-rw-rw- controls    staff
q          5   0x18be     --rw-rw-rw- controls    staff
q         56   0x1d9f     -Rrw-rw-rw- controls    staff
q          7   0x1e56     -Rrw-rw-rw- controls    staff
q          8   0x1efd     -Rrw-rw-rw- controls    staff
q        109   0x2044     -Rrw-rw-rw- controls    staff
q         10   0x207a     -Rrw-rw-rw- controls    staff
q         11   0x24c4     -Rrw-rw-rw- controls    staff
q         12   0x24d7     -Rrw-rw-rw- controls    staff
q         13   0x251b     -Rrw-rw-rw- controls    staff
q         14   0x2fe8     -Rrw-rw-rw- controls    staff
q        115   0x3a65     -Rrw-rw-rw- controls    staff
q        116   0x967      -Rrw-rw-rw- controls    staff
q         17   0x98e      -Rrw-rw-rw- controls    staff
q        118   0x456c     -Rrw-rw-rw- controls    staff
q        669   0x194      -Rrw-rw-rw- controls    staff
q        620   0xe70      -Rrw-rw-rw- controls    staff
q         71   0x15d0     -Rrw-rw-rw- controls    staff
q        222   0x3586     -Rrw-rw-rw- controls    staff
q        173   0x5e37     -Rrw-rw-rw- controls    staff
q        624   0x5e4d     -Rrw-rw-rw- controls    staff
q        475   0x10d7     -Rrw-rw-rw- controls    staff
q        176   0x5ee3     -Rrw-rw-rw- controls    staff
q        277   0x4e22     -Rrw-rw-rw- controls    staff
q        428   0x25f3     -Rrw-rw-rw- controls    staff
q         29   0x3354     -Rrw-rw-rw- controls    staff
q        180   0x368f     -Rrw-rw-rw- controls    staff
q        131   0xb0f      -Rrw-rw-rw- controls    staff
q         82   0x47a5     --rw-rw-rw- controls    staff
q         83   0x4b83     -Rrw-rw-rw- controls    staff
q         34   0x4f6d     -Rrw-rw-rw- controls    staff
q         85   0x4539     -Rrw-rw-rw- controls    staff
q         86   0x67a1     --rw-rw-rw- controls    staff
q         37   0x4b7      -Rrw-rw-rw- controls    staff
q         38   0xd37      -Rrw-rw-rw- controls    staff
q         39   0x156c     -Rrw-rw-rw- controls    staff
q         40   0x2b62     -Rrw-rw-rw- controls    staff
op440m:~>rmq
---------------------------------------------------------------
Deleting message queues which are owned by user: controls ....
---------------------------------------------------------------
      Deleted message queue: 400
      Deleted message queue: 1
      Deleted message queue: 2
      Deleted message queue: 103
      Deleted message queue: 4
      Deleted message queue: 5
      Deleted message queue: 56
      Deleted message queue: 7
      Deleted message queue: 8
      Deleted message queue: 109
      Deleted message queue: 10
      Deleted message queue: 11
      Deleted message queue: 12
      Deleted message queue: 13
      Deleted message queue: 14
      Deleted message queue: 115
      Deleted message queue: 116
      Deleted message queue: 17
      Deleted message queue: 118
      Deleted message queue: 669
      Deleted message queue: 620
      Deleted message queue: 71
      Deleted message queue: 222
      Deleted message queue: 173
      Deleted message queue: 624
      Deleted message queue: 475
      Deleted message queue: 176
      Deleted message queue: 277
      Deleted message queue: 428
      Deleted message queue: 29
      Deleted message queue: 180
      Deleted message queue: 131
      Deleted message queue: 82
      Deleted message queue: 83
      Deleted message queue: 34
      Deleted message queue: 85
      Deleted message queue: 86
      Deleted message queue: 37
      Deleted message queue: 38
      Deleted message queue: 39
      Deleted message queue: 40
---------------------------------------------------------------
op440m:~>
  578   Thu Jun 26 20:59:22 2008 ranaUpdateComputer Scripts / ProgramsAlarm Handler
Please do not turn off the Alarm Handler on op540m.
  579   Thu Jun 26 21:07:11 2008 ranaConfigurationASSdust & MC1
I realized today, that yesterday while we were trying to debug the adaptive noise canceler, I turned
off the analog dewhitening on MC1. I did this by changing settings on the Xycom screen but I
forgot to elog this -- this may have caused problems with locking via increased frequency noise.
I have now returned it to its nominal, dewhitening on, configuration.

I also used mDV to look at the last year of dust trend. I have plotted here the cumulative
histogram in percentile units of the 0.5 micron dust level. The x-axis is in units of particles per cu. ft.
and the y-axis is percentage. For example, the plot tells us that over the last year, the counts were
below 6000, 90% of the time. I have set the yellow and red alarm levels to alarm at the 95-th and 99-th
percentile levels, respectively.
  593   Sun Jun 29 18:58:43 2008 ranaSummaryComputers1e20 is too big for AWG and/or IOVME
While testing out my matlab/awgstream based McWFS diagnostic script I accidentally put a
huge excitation into
C1:IOO-WFS1_PIT_EXC
. This went to 1e20 and then caused
some SUS to trip and c1susvme2 to go red. I tried booting it via the normal procedures
but it wouldn't come back, even after 2 crate power cycles. I also tried booting AWG
via the vmeBusReset, but that didn't do it. Then I booted c1iovme from the telnet prompt
and then I could restart c1susvme2 successfully.

The reason the excitation was so large is that the following filter command is unstable:
[b,a] = butter(4,[0.02 30]/1024);

The low pass part is OK, but it looks like making such a low frequency digital filter
is not. Que lastima. On the bright side, the code now has some excitation amplitude
checking.
  594   Sun Jun 29 19:19:47 2008 ranaSummaryIOOTrends of the PSL/IOO Quads over 1000 days
Only IOO POS has been working for the past 2 years. I guess we should recommission the IOO ANG and REFL QPDs
  597   Sun Jun 29 20:29:48 2008 ranaUpdatePSLCorrelation of PSL SLOW control v. Room temperature
  662   Sat Jul 12 23:28:31 2008 ranaUpdatePSLPMC needs help
As everyone has noticed recently, the PMC seems to have a PZT problem. It often zooms
of to one of its rails after locking as if the PZT range has decreased dramatically.

WE should check this on Monday by disabling the FSS and applying a slow triangle wave to
the NPRO frequency. The PMC will track this frequency change and this will allow us to
diagnose its problems.

If it has real problems, I have a spare in W. Bridge which we can swap in temporarily.

The attached plot shows 3 years of trend; looks like it went bad in summer of last year.

This also seems to be the cause of our ISS saturation problems: lowering the gain of the PMC
even slightly increased the intensity noise enough to cause saturation. Increasing the gain
even slightly increased the intensity noise enough to cause saturation due to PMC servo oscillation.
  663   Sun Jul 13 17:19:29 2008 ranaSummaryPSLMOPA SLOWM Calibration
John, Rana

We first unlocked the FSS and ramped the SLOW actuator. With the PMC locked we observed the PMC PZT voltage
as a function of SLOWM (SLOW loop actuator voltage). We believed this to be ~1-5 GHz / V. Since this is
not so precise we then ran a slow (2 min. period) triangle wave into the slow actuator and looked at the
ref cav transmission peaks to calibrate it.

Plot is attached>

We assume that the reference cavity length = 203.2 mm then the FSR = 737.7 MHz. So looking at the plot
and using our eye to measure the SLOWM calibration is 1054 +/- 30 MHz/V. This is probably dominated by
our eye method.

Note: we tried to get the length from T010159-00-R (Michele, Weinstein, Dugolini). In that doc,
the length used is 203.3 mm whereas its 203.2 mm in the PSL FDD (?). The calculation of the FSR is also
incorrect (looks like they used c = 299460900 instead of 299792458 m/s). We took the length from the PSL FDD
(T990025-00-D) but not the FSR, since they also did not find the right value of 'c'. I guess that the speed
of light just ain't what it used to be.
  676   Tue Jul 15 19:15:57 2008 ranaSummarySUSETMX Dewhitening characterization
Since the boys found that the ETM dewhitening transient was kicking the IFO out of lock we
decided to investigate.

First, we wrote a script to diagnose and then tune the DC gain of the dewhitening filters'
digital compensation filter (a.k.a. FM9 or SimDW). It is in the scripts/SUS/ directory
and is called dwgaintuner. It puts in an offset on each coil's DAC channel and
then reads back the Vmon on the coil driver with the DWF on and off. It reports the ratio of these
voltages which you can then type into the FM9/SimDW filter's gain field. We learned that the
difference between the analog DWF path and the bypass path was ~3% (which is consistent with
what you expect from the use of 1% resistors). We need to repeat this for all of the rest of
the suspended optics except for MC1 and MC3.

This Vmon method is better than what's used at the sites so we will export this new technology.

The attached plot shows some switching transients with only the local damping on:
BLUE:   Output of filter bank during an FM9 turn off. This is the transient which goes to the DAC.
        The transients are mostly of the same magnitude as this.
RED:    This is the input of the filter module during another such transient.
GREEN:  Tried another switch; this time I filtered the time series in DTT by typing the SimDW into
        the Triggered Time Series filter field. This should be simulating what comes out of the
        output of the DW board - to convert to volts multiply by 15/32768.
PURPLE: Same kind of filtering as the GREEN, but with also a double 30 Hz highpass to remove the low
        frequency damping control signals. You can see that the total transient is only ~5 counts
        or ~1 mV at the coil driver output. This is comparable to the relative offset in the bypass
        and filter paths.
  713   Tue Jul 22 11:55:22 2008 ranaUpdatePSLNote from R. Abbott re: the PMC
an email from Rich:
Your PZT is broken.

R
  718   Tue Jul 22 22:25:31 2008 ranaUpdateLSCLooptickle for existing 40m
John and I have adapted the Stefan-Looptickle model of the 40m upgrade to have the parameters of the old one.
(old one = what we have had for the last 4 years).

Its in the /cvs/cds/caltech/iscmodeling directory on the CDS computers but you can also check it out from the
MIT CVS repo; its part of the whole shebang.

It makes the attached theoretical NB. Feel free to modify it.
  719   Wed Jul 23 01:42:26 2008 ranaConfigurationPSLFSS RFPD: Examined, "repaired", and re-installed
Rob said that there might be something wrong with the FSS RFPD since the loop gain is so low.
Next time we should just use the Jenne laser on it in-situ and compare with our reference.

We had a 24.5 MHz LSC PD which Rob got from Sam. Sam got it from Rai. I gave it to Rai in Livingston
because it seemed suspicious. Seems fine now. This black box PD had a lower overall response than
the goldbox one we already had. The 2001-2005 era diodes which we got from the Canadian Perkin-Elmer
all had high capacitance and so that's not a surprise.

So the goldbox one was not broken totally.

I found that the offset came from a cracked capacitor. C25 was a yellow thru-hole ceramic 0.1 uF.
Its a surface mount board...don't know why this was like this but there's also no reason it should
have cracked unless it was soldered on with too much heat. I replaced it with a 0.47 uF ceramic
surface mount. Also R24 was a 20 Ohm resistor and L3 was not stuffed?? Removed R24 and put a 1 uH
inductor into L3. This is there so that the input to the MAX4107 is AC coupled.

However, the DC signal that Rob saw was actually because of the cracked C25. It had shorted and was
making a 25 mV signal at the input to the MAX4107 which has a gain of 10. This was producing ~165 mVdc
into a 50 Ohm load and so it could have saturated most mixers. The FSS board, however, has an overly
monstrous level 21 (I think) mixer and so this should not have been an issue. Maybe.

I was able to lock with the 24.5 MHz black box PD but it was not too hard to repair the gold box one
so I did. I tuned it so that the notch is truly at 43 MHz (2x the FSS 21.5 MHz modulation) but because
someone has done this using a hacky cap in parallel with the main PD, I am unable to get the resonant
peak to line up at 21.5 MHz. Its at 23 MHz instead. This loses us ~2 dB in signal. Since the frequency
is so low, we can increase the gain in the MAX4107 by another factor of 3 or so in the future.


So the PD is not our problem. Still worth verifying that the cable is good -- its around 10 miles long!!
And loops around in there with a bunch of other cables. We have an electronic phase shifter so this seems
totally misguided.

The other bad problem is that the mode matching is pretty horrible. Something like 1/3 of the carrier
power doesn't go into the cavity.
FSS TODO:
1) Check cable between RFPD and FSS box for quality. Replace with a good short cable.

2) Using a directional coupler, look at the RFPD output in lock on a scope with 50 Ohm term.
   I suspect its a lot of harmonics because we're overmodulating to compensate for the bad
   mode matching.

3) Purchase translation stages for the FSS mode matching lenses. Same model as the PMC lenses.
   Fix the mode matching.

4) Get the shop to build us up some more bases for the RFPDs on the PSL such as we have for the LSC.
   Right now they're on some cheesy Delrin pedestals. Too soft...

5) Dump the beam reflected off the FSS RFPD with a little piece of black glass or a razor dump.
   Anodized aluminum is no good and wiggles too much.

The attached PDF shows photos of the old and new style PDs. One page 3 there's a wire that I soldered on
as a handle so that we can remove the RF can (occasionally people claim that soldering to the lid screws
up the magnetic shielding magic of the lid. use this as a litmus test of their electronics know-how; its
a tin can - not an orgone box). Pages 4 & 5 are the circuit before I soldered, page 6 the cap after I
tried to remove it, page 7 is the circuit after I put in the new cap, and page 8 is the schematic with
the mark up of the changes.
  736   Thu Jul 24 21:04:58 2008 ranaUpdatePSLFSS
Since Jenne and Yoichi are going to finish up their refcav/FSS work in the morning I decided to
look at the trends. I set the RF modulation level from 10.0 back down to 7.5 so that we would
have the same RF modulation depth as before. I also set the FSS common gain and its nominal to
1.0 dB since it seemed more stable this way.

With 7.5, the transmission of the refcav is ~6.9 V. It was around 0.7 V before so there's already
been a factor of 10 improvement in the power since the work started. In addition to the mode matching
work which is about to commence, we should attenuate the RC TRANS with a real mirror (not ND) so that
the camera and PD don't saturate. We should also do the same for the REFL PD and camera and make sure
to put in a steering mirror for the REFL PD and orient REFL so that it faces West (so that we can
look at its face with a viewer) and dumps its reflection.

Since the common gain is so low now, I expect that we will want less light in total. We can achieve
this by turning down the RF drive to the VCO.

I also fixed the MC down script which was putting the FSS common gain to the unstable +10 dB level
during the MC locking process.
  737   Thu Jul 24 21:53:00 2008 ranaSummaryTreasureHigh School Tour group and the PMC
There was a tour today of 40 high school kids. I warned them that the lasers could burn out their
eyes
, that the vacuum could suck them through the viewports like tubes of spaghetti and that the
high voltage amps would fry their hair off.

One of them was taking a picture of the SOS in the flow bench and another one was whispering what
a dumb idea it was to leave a sensitive clean optic out where people might breathe on it. I told
one them to cover his mouth. The other one asked what was the glass block behind the SOS.

It was a spare PMC! s/n 00-2677 with a 279 nF capacitance PZT. I guess that this is the one that
Go brought from MIT and then left here. So we don't have to take the one away from Bridge in the
35 W laser lab.

We can swap this one in in the morning while the FSS people work on the reference cavity
alignment. Please email me if you object to this operation.
  743   Sun Jul 27 20:25:49 2008 ranaConfigurationEnvironmentOffice Temperature increased to 75 F
Since we have the chiller for the PSL chiller now, I've just increased the office area
temperature set point by 2 F
to 75 F to see if the laser will still behave.
  744   Sun Jul 27 20:49:21 2008 ranaConfigurationComputersNTP
After Aidan did whatever he did on op440m, I had to restart ntpd. I noticed it didn't actually do
anything so I restarted it by hand with the '-l' option to make a logfile. Essentially, the
problem is that NTPD is not allowed access to the outside world's NTP servers by our NAT router;
this should be fixed.

So for now I set all of the .conf files to point to rana and nodus' IP addresses. According to the
log files, that is successful. Rosalba and Mafalda, however, seem to have correct time but are
looking at rhel.ntp.pool.org and time.nist.gov, respectively. Maybe these have special rules?

For reference, the linux machines' conf files are /etc/ntp.conf
and the solaris machines' conf files are /etc/inet/ntp.conf

I also logged into dcuepics (aka scipe25) and did as instructed.
  745   Sun Jul 27 23:06:17 2008 ranaUpdatePSLPMC, MZ, MC-MMT, etc.
With the new PMC now in I aligned the MZ to the new beam (there is sadly no steering
between the PMC and the MZ).

I also removed the pickoff that we had put before the MZ just in case we wanted to
move the FSS pickoff to there - its been 2 years now so I guess its not going to happen.


The new PMC's cavity axis seems to be a few hundred microns higher than the old one. So I
tried to move the MZ EOMs to compensate but ended up also steering all of the MZ's mirrors
to get the contrast good, the beam onto the ISS PDs, centered (sort of) onto the MMT lenses
and onto the periscope.

Along the way I also removed some of the vestigial squeezer stuff around the power control
PBS. The output of the PBS now goes directly into the high power dump with no steering. This
eliminated around a dozen clamps, bases, etc. and a couple of mirrors.


The MC is locked on the low power beam we have running through everything. I restored the
PSL launch beam just using the MC-WFS and it locked on a TEM00. So now we know that we
really don't need the PSL quads for this as long as the MC1 angle is stable.

The good news is that the PMC PZT voltage is now flat: the problem must have really been with
the PZT
and not the cabling or notch box like I had wondered about.

Todo:
-----
1) Continue mode matching into the PMC. Its transmission now is around the same as the
   old one.

2) Put a UHV foil covered lead brick onto the PMC to quiet it down.

3) Characterize the PMC loop and retune the body notch for the new body.

4) Tweak the MZ alignment to minimize the RFAM. We can use StochMon to do this as
   long as we have the MC WFS turned off or we can put in a flipper to take the
   beam before the MC and send it to the StochMon RFPD.

5) Re-align onto the ISS.

6) Install irises around the periscope for the beam. The old iris there is way off.

7) Fix PSL ANG and center both POS and ANG.
  749   Mon Jul 28 17:44:07 2008 ranaUpdatePSLPMC PZT v. temperature
This plot shows that the PMC PZT has ~20 Vpp fluctuations on a 24 hour timescale
which is correlated to the 24 hour temperature fluctuations. By contrast, the MZ
has ~75 Vpp
.
  755   Tue Jul 29 13:54:08 2008 ranaUpdateSUSETMY and PRM have EQ related problems
The attached trend shows that ETMY and PRM both had large steps in their sensors
around the time of the EQ and didn't return afterwards. The calibration of the
OSEM sensors is ~0.5 mm/V. The PRM sensors respond when we give it huge biases
but there is very little change in the ETMY. Almost certainly true that the
optics have shifted in their wire slings and that we will have to vent to
examine and repair at least ETMY.

Jenne is looking at the spectra of the other suspensions to see if there is
other more subtle issues.
  762   Wed Jul 30 00:42:04 2008 ranaUpdateSUSTrends and file formats
I propose that we do not use .eps format but .pdf instead. For images like the plots Sharon
has below we should use only .png and for pictures like what Steve posted, use JPG or PNG.

PDF is a standard and light weight. PNG is very good for plots/lines and is lossless. JPG does
a good job with regular camera pictures because we don't really care about the compression
loss on those.

Here's a trend of the UL sensors for all the optics - conversion is 32768 cts / mm. You can see
that the quake was just before 19:00 UTC (noon our time). The events an hour after are when
Rob, Jenne, and I start exciting the optics to shake them loose - wanging the pit/yaw sliders
around is not violent enough and so I injected a 130000 count sine wave at 0.5 Hz so as to
create a high force square wave. This seems to have worked for ETMY but no such luck yet with
the others.
  763   Wed Jul 30 01:08:50 2008 ranaSummarySUSSUS Drift Screen
This is a snap of the SUS Drift screen with all of the optics biases set back to their nominal
values except for the MC which Rob aligned and I didn't feel like mis-aligning. The reference
on the screen is from 3/25 when Andrey felt that Rob had a good IFO alignment.

Anything more than a few thousand is significant and more than 10k means something is wrong:



I wailed on the PRM for awhile and was able to loosen it up a little. The LL & LR sensors now
show some life one the dataviewer. The UL & UR are still railed ~1.6 V so that means that the
optic is pitched back. With aggressive pitch wailing I can see the PRM's ULR/UR sensors go
rail to rail so that means that the magnets are still on - although they may be half busted.
If they're OK we should be able to just re-sling this guy.


Did the same on SRM. The OSEM values have shifted on these, but not disastorously. The SIDE,
however, is completely unresponsive. The little signal I see when driving is is probably just
capacitive pickup in the cables. Have to vent to fix this one.


ITMX Has good life in all but the LR & UR channels. They respond, but the signal is very weak.
Seems like these magnets have not fallen off but that they are not between the LED/PD anymore.


ITMY seems ok. Check the spectra to be sure.


BS seems ok as well. Swings freely and no kinks in the swinging sensor waveforms. Check the spectra.
  770   Wed Jul 30 15:12:08 2008 ranaSummaryIOOHistory of the MC abs length
> I was notified by Rob and Rana that there were many measurements of the MC abs length (i.e. modulation
> frequencies for the IFO.) between 2002 and now.

I will just add that I think that the Marconi/IFR has always been off by ~150-200 Hz
in that the frequency measured by the GPS locked frequency counter is different from
what's reported by the Marconi's front panel. We should, in the future, clearly indicate
which display is being used.
  773   Wed Jul 30 18:45:01 2008 ranaConfigurationSUSNew SUS Drift Technology
I updated the SUS DRIFT screen again, this time with a new feature.

I used Rolf's idea for the AdvLIGO status system and just made the nominals be an
unused sub-field (.SVAL) of the main INMON record. Then I wrote a .csh script to
use tdsavg to average the current INMON vals and insert that as the .SVAL. The next
script should read the .SVAL and set the HIHI and LOLO based on this.

Of course, the values I have just entered are no good because our suspensions are in
a bad state but we can run this script (SUS/setDriftNoms) next time things are good.

And...even better would be if someone were to do the same but used mDV to grab the
minute trend in the past good times instead of the tdsavg (which can't go in the past).
  775   Thu Jul 31 10:27:17 2008 ranaUpdatePSLPMC Scan Graphs

Quote:
Graphs of the PMC scan data that I got earlier today.

On the UNIX computers, one can use 'convert' to change these to PNG. A DC offset should be added to the transmitted
light so that the scan can be plotted with a log y-scale. And, of course, Acrobat can be used to make it into a
single PDF file.

The PMC scan always has this distortion and so the input power has to be decreased to a few mW to reduce the
thermal expansion effect; the expansion coefficient for SiO2 is ~5 x 10^-7 / K and we're worried about nm level
expansions.
  778   Fri Aug 1 01:13:32 2008 ranaConfigurationPSLPSL Quad change and new script
Koji and I changed a few optics so that now ~60% of the beam that went to the PSL POS QPD
now goes to the west side of the table for the aux. laser locking PLL. The beam is sort of
on the QPD again but needs a centering.

After this work I wrote a script SUS/freeswing-all.csh which puts a 30000 count offset into
the UL coil of each suspension and then disables it. This is just good enough to kick it up
so that the eigenfrequency can be measured. I ran it and it worked -- it finished running at

Fri Aug 1 00:44:30 PDT 2008
  781   Fri Aug 1 16:33:52 2008 ranaConfigurationPSLPSL Quad change and new script
Here's the sensor ringdown trend from the kick.
  784   Sat Aug 2 16:05:38 2008 ranaConfigurationComputer Scripts / ProgramsmDV update
I did an svn update on our mDV directory. Justin has improved it so that the NDS client binaries
are included for solaris, mac, linux32, and linux64. Now you can just use this version without
having to worry about any path definitions.
  785   Sat Aug 2 18:37:41 2008 ranaUpdateSUSOSEM Spectra

The attached PDF file is from the .xml files that I found from 7/30. Looks like someone
took some free swinging data and even made nice plots but didn't elog it. Raspberry for you.
The data files are saved in Templates/FreeSwinging/{ETMX,ETMY,etc.}/2008_07_30.xml

The top left plot on the multi-page file all have the same scale so you can see what's happened.
The peaks should all be as measured by Busby in Sep '06
but instead they are as you see here.
  786   Sun Aug 3 20:53:54 2008 ranaConfigurationPEMGuralp
We got our repaired Guralp back in the mail from England (s/n T4157). I plugged it in
to Ben's 3-Guralp breakout box (http://www.ligo.caltech.edu/docs/D/D060506-00.pdf) and
verified that it is not oscillating (like it was before) and that it responds to us
jumping around.

The breakout box has way too much gain, however. The ADC wants +/-2 V and the box puts out
~5 Vpk in the night time.

Looking at the schematic, it has a DC gain of 200 and a double whitener (50,50:10,10) so that
there's a gain of 5000 from 50-2000 Hz. The Guralp has a transduction gain of 800 V/(m/s) and
so we can just calculate what the frequency dependent noise figure of the box has to be. I've
pulled it out, put it on the bench, and started reworking it. I am looking for a soldering/
testing volunteer.

The other kink in the problem is that since we want to use this for the adaptive noise cancellation,
we have to make the noise floor of the readout better than the ambient noise by the same factor
with which we want to cancel the noise.
  808   Thu Aug 7 10:27:59 2008 ranaUpdateSUSFree swinging OSEM spectra
Sometimes we see extra peaks in the OSEM spectra coming from a beat between the regular eigenmodes.
This probably comes from the OSEM shadow sensor not being entirely linear - the nonlinearity is
greatly increased if the magnet is not perfectly centered in the LED beam. So the beats are
probably there at some level in all of them; usually below the noise.
  812   Fri Aug 8 09:54:10 2008 ranaUpdateCamerasNew code + gstreamer allows for easy saving and compression of images

Quote:
Modified the CamSnap code to output the image data stream to standard out. This can then be piped into a gstreamer plugin and then be used


Didn't work; Prosilica has only 1 "l". Even so, sshing from op440m to mafalda, I got this:
mafalda:SnapCode>CamSnap -F 'Mono8' -c 44058 -E 5000 -X 0 -Y 0 -H 480 -W 752 -l 0 -m 300 | gst-launch-0.10 fdsrc fd=0 blocksize=360960 ! video/x-raw
-gray, height=480, width=752, bpp=8,depth=8,framerate=30/1 ! ffmpegcolorspace ! theoraenc ! oggmux ! filesink location="./testVideo.ogm"
Setting pipeline to PAUSED ...
Pipeline is PREROLLING ...

** (gst-launch-0.10:27121): WARNING **: Size 60 is not a multiple of unit size 360960
Caught SIGSEGV accessing address 0x487c
ERROR: from element /pipeline0/ffmpegcsp0: subclass did not specify output size
Additional debug info:
gstbasetransform.c(1495): gst_base_transform_handle_buffer (): /pipeline0/ffmpegcsp0:
subclass did not specify output size
ERROR: pipeline doesn't want to preroll.
Setting pipeline to NULL ...
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb7deddae in __lll_mutex_lock_wait ()
#2  0xb7de9aac in _L_mutex_lock_51 () from /lib/tls/i686/cmov/libpthread.so.0
#3  0xb7de949d in pthread_mutex_lock ()
#4  0xb7e452e0 in g_static_rec_mutex_lock () from /usr/lib/libglib-2.0.so.0
#5  0xb7f1fa08 in ?? () from /usr/lib/libgstreamer-0.10.so.0
#6  0x080c1220 in ?? ()
#7  0x00000001 in ?? ()
#8  0x0809586c in ?? ()
#9  0x00000001 in ?? ()
#10 0x08095868 in ?? ()
#11 0xb7f7a2a8 in ?? () from /usr/lib/libgstreamer-0.10.so.0
#12 0xb7e8da80 in ?? () from /usr/lib/libglib-2.0.so.0
#13 0xb7f7a2a8 in ?? () from /usr/lib/libgstreamer-0.10.so.0
#14 0xb7f7a2a8 in ?? () from /usr/lib/libgstreamer-0.10.so.0
#15 0x00000000 in ?? ()
Spinning.  Please run 'gdb gst-launch 27121' to continue debugging, Ctrl-C to quit, or Ctrl-\ to dump core.
Caught interrupt -- 
  819   Sun Aug 10 16:57:02 2008 ranaSummaryPhotosPhotos from Vent 8/4 - 8/8
http://www.ligo.caltech.edu/~rana/40m/VentAug08/

I've added the D40 pictures from last week to this web page. I have done some cropping and
rotating to make things look better.

On page 3, there are some over head shots of the Michelson area so that one can use screw holes
to judge what the spacing between the suspensions is and also possibly the cavity lengths. Lets
also remember to measure the ITM-BS distance accurately using a tape measure or ruler while we
have the thing open.
ELOG V3.1.3-