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New entries since:Wed Dec 31 16:00:00 1969
ID Date Author Typedown Category Subject
  401   Tue Mar 25 13:21:25 2008 AndreyUpdateComputersc1susvme2 is not behaving itself again
  402   Tue Mar 25 15:56:09 2008 JohnUpdateTreasureAssorted pictures
Some pictures scavenged from the D40.
  403   Tue Mar 25 16:34:47 2008 robUpdateComputersc1susvme2

Quote:

Quote:
c1susvme2 isn't behaving itself. It keeps getting out of sync and/or giving a red status light.

After going through the usual restart procedures a few times (unsuccessfully) we power cycled the c1susvme & c1sosvme crates. We think everything came back okay.

We still can't get the status and CRC (cyclic redundancy check) to return to normal on c1susvme2. If Alex is around tomorrow please ask him to take a look.


I rebooted it again this morning. The ASS machine is currently not running its process, for whatever reason (someone turn it off?). Let's leave it like this for a day and see how the c1susvme2 does. The other recent change is Steve's install of a cooling fan--maybe that's causing the problem.


Now c1susvme1 is joining the action. Since leaving the ASS off doesn't change anything, we can probably absolve it of blame. I now suspect the 4-pin LEMO cables going from the CLK DRIVER modules to the clock fanout modules. These cables are being squeezed/shaken by Steve's new fan setup, and may have been the culprit all along. John will do some testing to see if they are indeed the problem.
  405   Wed Mar 26 22:26:15 2008 JohnUpdateComputersc1susvme
I removed the fan and tweaked the timing cables to see if they were the source of our problems. I saw no effect. I'm leaving the fan off for the moment to see if that helps. It is on top of the filing cabinet next to my desk.
  406   Fri Mar 28 16:18:18 2008 robUpdateComputersc1susvme2 status
c1susvme2 is getting worse and worse. it won't run for more than ~45 minutes without fatally de-syncing. for now I've turned off c1iovme (which sends the MCL signal) to see if that's causing the problem. next I'll swap the boards for c1susvme1 and c1susvme2 to see if it's the cpu (or maybe the RFM card) itself, rather than the timing/pentek systems.
  408   Mon Mar 31 14:14:16 2008 robUpdateComputersc1susvme2 status

Quote:
c1susvme2 is getting worse and worse. it won't run for more than ~45 minutes without fatally de-syncing. for now I've turned off c1iovme (which sends the MCL signal) to see if that's causing the problem. next I'll swap the boards for c1susvme1 and c1susvme2 to see if it's the cpu (or maybe the RFM card) itself, rather than the timing/pentek systems.


I swapped the processors for c1susvme1 and c1susvme2. So for now, to startup, you should ssh into c1susvme1 and run the startup.cmd for c1susvme2, and vice versa.
  409   Wed Apr 2 15:03:51 2008 steveUpdateGeneralreflectivity of black glass
The reflectivity of black glass, shade 12 was supplied by Donald O'Shea
of Emerald Glass Inc., Westlake, OH 44145

The reflectivity of this glass was measured as shown

Old 1064 nm Crysta Laser with poor beam quality was the source.
  416   Mon Apr 7 16:42:56 2008 ranaUpdateComputerseLog intermittent
Phil Ehrens restarted Dziban again this morning. Looks like its still crashing each Monday around 8 AM.

Here is the latest suspect:

http://open.itworld.com/5040/reboot-unix-nlsunix-071225/page_1.html
  417   Mon Apr 7 18:58:49 2008 steveUpdateGeneralreflectivity of SS304
The reflectivity of stainless steel 304 super polished # 8 was measured the same way as elog entry 409

The reflectivity: 74 +- 1 % from incident angle 10 to 80 degrees
  421   Wed Apr 16 10:20:01 2008 AndreyUpdateComputersRosalba and linux3

Quote:
There is a new computer in the control room -- its called Rosalba,
in keeping with our naming convention. Its a quad-core machine that
Dmass found for cheap somewhere; we've installed the CentOS on it
that Alex recommended.

Its a 64-bit Linux and so that may cause some problems. Alex has done this
before and so we have some confidence that we can get our regular tools (DTT, Dataviewer)
to run on it.

I have made a new apps tree for all of our future 64-bit Linux machines. So far, there is
a 64-bit firefox and a 64-bit matlab in there. As we start using this machine some more, we
will be forced to install more 64-bit Linux stuff.

We also didn't have enough network cables to run to both linux3 and rosalba. Andrey has decided that we
should not ditch linux3 and so he will run another cable for it tomorrow.


The ethernet cable for linux3 was installed on Wednesday morning. Now linux3 has Internet connection again.
  423   Thu Apr 17 15:00:59 2008 steveUpdateVACvac controller computer to be replaced
Now that Rosalba is up and running someone should step forward to volunteer for this job.

Old desk top at the Vacuum Rack should be replaced by a functional less old computer so
the vacuum controller can count on an emergency situation. It's only has to be able to run medm
The existing one is dying.
  424   Thu Apr 17 20:17:37 2008 AndreyUpdatePEMTwo issues with our weather station

I encountered two difficulties working with the "Weather Station".

(1) It turns out that there is no indication for "outside humidity" on the "weather monitor" (a small black box located on the north wall of the interferometer). I realized that "outside humidity" is absent in our system when I tried to see the Dataviewer trend and real-time value from the channel "C1: PEM-weather-outsideHumid". It shows impossible number 128%.

It follows from the "Davis" technical documentation that the outside sensor can be of two types: either "External Temperature Sensor" or "External Temperature/Humidity Sensor". I suspect (I do not know for sure) that we have the first type of sensor "external temperature only" and therefore we in principle cannot have information about outside humidity. I propose to Steve to climb to the roof on Friday to resolve this uncertainty looking at the sensor.

(2) I wanted to change the units of pressure from "Pascal" (force/area) to other units, "mbar" for example. For this purpose I need to edit the file "Weather.st" in the directory /cvs/cds/caltech/target/c1pem1 (this file is run on the VME processor "c1pem1"). Unfortunately, when I try to open the file with emacs, I get the message that the file exists but protected from modifications. I do not know how to unblock the file "Weather.st". I need some help with that.

I thought that switching-off the processor "c1pem1" could resolve the issue, so I switched-off the whole crate where the processor "c1pem1" is installed for about 5 minutes, turning the metallic key. As it did not make any difference for the accessibility of the file "Weather.st", I switched-on the crate after 5 minutes. There are other processors besides "c1pem1", so they were turned-off for several minutes earlier today.

Also, I created a new MEDM screen which has information about weather only, a smaller version of the "C0Checklist.adl" MEDM screen. Both screens are now located under the most top-left button "Checklist" of the main MEDM screen.
  425   Fri Apr 18 16:02:58 2008 alexUpdateSUSend station sus front-end bug fix
installed and started new susEtmx.o and susEtmy.o to fix a problem with ETMY optical lever variables.
  426   Fri Apr 18 16:27:04 2008 robUpdateSUSend station sus front-end bug fix

Quote:
installed and started new susEtmx.o and susEtmy.o to fix a problem with ETMY optical lever variables.


But where is the code?
  427   Fri Apr 18 16:48:13 2008 AndreyUpdatePEMRain collector of weather station

Today the rain collector of our weather station was cleaned. As a result, we checked that the rain indication on the weather monitor and on the MEDM screens is alive and working properly. I am adding some details about the roof sensors to the wiki-40 page about the weather station. See especially the link "More description of the roof sensors and their interaction with UNIX computers" from the main Weather Station page in wiki-40.

Pictures of the rain collector before (dirty, the opening is fully clogged with dust and dirt) and after (clean opening in the bottom of the bowl) the cleaning are attached.
  428   Fri Apr 18 19:46:08 2008 ranaUpdateASScheck adaptive
I restarted the adaptive code today using 'startass' and 'upass'.
I moved them into the scripts/ASS/ subdirectory.

Things seem OK. With a MU=0.03 and a TAU=0.00001, there is a still
a good factor of 10 reduction of the 3 Hz stack peak from the MC2
drive by doing FF into MC1.

I edited the ASS-TOP screen so that we could see such small numbers. I
also re-aligned the MC SUS to match the input beam (mainly MC3). The
cavity was locking on a TEM10 mode mostly -- we should look in the SUS
OSEM trends to see if MC3 has moved a lot in the last month or so.

Caryn Palatchi (a Caltech undergrad who just started working with us)
illustrated to me today that using even 1000 FIR taps is not very effective
for low frequency noise cancellation if you have a 2048 Hz sample rate. More
precisely, the asymptotic Wiener filter which our 'LMS' algorithm converges
to, can often amplify the noise at frequencies below f_sample/N_taps.

A less obvious thing that she also noticed is that there is almost no cancellation
of the 16.25 Hz bounce mode when using such a short filter. That's because that
mode is fairly high Q: the transfer function from the Z-ACC to the cavity signal
goes through the high-Q vertical suspension resonance; the FF signal we send back
goes through the low-Q horizontal pendulum response only. Therefore the filter
needs to be able to simulate ~100 cycles at 16.25 Hz in order to cancel that peak.

Duh.

The message here is: we need to find a computationally efficient way to do FIR filtering
or its not going to ever be cool enough to help us find the Crab.
  430   Sun Apr 20 20:29:46 2008 ranaUpdateComputer Scripts / Programstdsread bugs
There seems to be a problem with reading the C1:IOO-MASTER_OVERFLOW field
when it is read in as part of an array. The only way for me to describe it
is to just attach the terminal output in this entry...this is mainly for
Matt and Rob
.


I first noticed that the output of the MC-WFS sensing matrix was different than
the outputs from a year ago, namely that the excitation channel was not being
processed and outputted to the file. This made the output matrix diagonalization
scripts fail.

I noticed that there are several different copies of tdsread.cc sitting around.
Looks like they have been hacked in the last year but I am not sure if this
excitation channel readback is an intentional change; email has been sent to the
authors to find out -- they will probably post some kind of response in the log
to resolve what's up.


My guess is that the problem with the IOO channel is not related, but I'm not sure:
op440m:WFS>set ioo_head = "${ifo}:IOO-"
op440m:WFS>set sus_head = "${ifo}:SUS-"
op440m:WFS>set oflows = `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW ${sus_head}MC3
_MASTER_OVERFLOW ${ioo_head}MASTER_OVERFLOW`
ERROR: C1:IOO-MASTER_OVERFLOW value not read
op440m:WFS>set oflows = `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW ${ioo_head}MAS
TER_OVERFLOW`
ERROR: C1:IOO-MASTER_OVERFLOW value not read
op440m:WFS>set oflows = `tdsread ${ioo_head}MASTER_OVERFLOW`
op440m:WFS>set oflows = `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${ioo_head}MASTER_OVERFLOW`
ERROR: C1:IOO-MASTER_OVERFLOW value not read
op440m:WFS>set oflows = `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${ioo_head}MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW`
ERROR: C1:IOO-MASTER_OVERFLOW value not read
op440m:WFS>echo $oflows
0
op440m:WFS>set oflows = `tdsread ${ioo_head}MASTER_OVERFLOW`
op440m:WFS>echo $oflows
0
op440m:WFS>set oflows = `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW ${sus_head}MC3_MASTER_OVERFLOW`
op440m:WFS>echo $oflows
0 0 0
op440m:WFS>echo `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${ioo_head}MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW`
ERROR: C1:IOO-MASTER_OVERFLOW value not read
0
op440m:WFS>echo "tdsread ${sus_head}MC1_MASTER_OVERFLOW ${ioo_head}MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW"
tdsread C1:SUS-MC1_MASTER_OVERFLOW C1:IOO-MASTER_OVERFLOW C1:SUS-MC2_MASTER_OVERFLOW
op440m:WFS>
  432   Mon Apr 21 12:58:42 2008 robUpdateASScheck adaptive

Quote:


Caryn Palatchi (a Caltech undergrad who just started working with us)
illustrated to me today that using even 1000 FIR taps is not very effective
for low frequency noise cancellation if you have a 2048 Hz sample rate. More
precisely, the asymptotic Wiener filter which our 'LMS' algorithm converges
to, can often amplify the noise at frequencies below f_sample/N_taps.

A less obvious thing that she also noticed is that there is almost no cancellation
of the 16.25 Hz bounce mode when using such a short filter. That's because that
mode is fairly high Q: the transfer function from the Z-ACC to the cavity signal
goes through the high-Q vertical suspension resonance; the FF signal we send back
goes through the low-Q horizontal pendulum response only. Therefore the filter
needs to be able to simulate ~100 cycles at 16.25 Hz in order to cancel that peak.

Duh.

The message here is: we need to find a computationally efficient way to do FIR filtering
or its not going to ever be cool enough to help us find the Crab.


This is the reason for "RDNSAMP" parameter in the ASS code. The FIR filtration is applied at the downsampled rate, not the machine rate. So, if RDNSAMP=32, the effective sampling rate of the FIR filter is 64Hz, and thus noise cancellation should be good down to 64Hz/1000, or 64mHz, and the filter has an impulse response time that extends to 15 secs. I'm not convinced the filter length is what's limiting the performance at the bounce mode, but I agree that a faster FIR implementation would be good.
  433   Mon Apr 21 13:12:21 2008 robUpdateComputer Scripts / Programstdsread bugs

Quote:
There seems to be a problem with reading the C1:IOO-MASTER_OVERFLOW field
when it is read in as part of an array. The only way for me to describe it
is to just attach the terminal output in this entry...this is mainly for
Matt and Rob
.


I first noticed that the output of the MC-WFS sensing matrix was different than
the outputs from a year ago, namely that the excitation channel was not being
processed and outputted to the file. This made the output matrix diagonalization
scripts fail.

I noticed that there are several different copies of tdsread.cc sitting around.
Looks like they have been hacked in the last year but I am not sure if this
excitation channel readback is an intentional change; email has been sent to the
authors to find out -- they will probably post some kind of response in the log
to resolve what's up.


My guess is that the problem with the IOO channel is not related, but I'm not sure:
op440m:WFS>set ioo_head = "${ifo}:IOO-"
op440m:WFS>set sus_head = "${ifo}:SUS-"
op440m:WFS>set oflows = `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW ${sus_head}MC3
_MASTER_OVERFLOW ${ioo_head}MASTER_OVERFLOW`
ERROR: C1:IOO-MASTER_OVERFLOW value not read
op440m:WFS>set oflows = `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW ${ioo_head}MAS
TER_OVERFLOW`
ERROR: C1:IOO-MASTER_OVERFLOW value not read
op440m:WFS>set oflows = `tdsread ${ioo_head}MASTER_OVERFLOW`
op440m:WFS>set oflows = `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${ioo_head}MASTER_OVERFLOW`
ERROR: C1:IOO-MASTER_OVERFLOW value not read
op440m:WFS>set oflows = `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${ioo_head}MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW`
ERROR: C1:IOO-MASTER_OVERFLOW value not read
op440m:WFS>echo $oflows
0
op440m:WFS>set oflows = `tdsread ${ioo_head}MASTER_OVERFLOW`
op440m:WFS>echo $oflows
0
op440m:WFS>set oflows = `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW ${sus_head}MC3_MASTER_OVERFLOW`
op440m:WFS>echo $oflows
0 0 0
op440m:WFS>echo `tdsread ${sus_head}MC1_MASTER_OVERFLOW ${ioo_head}MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW`
ERROR: C1:IOO-MASTER_OVERFLOW value not read
0
op440m:WFS>echo "tdsread ${sus_head}MC1_MASTER_OVERFLOW ${ioo_head}MASTER_OVERFLOW ${sus_head}MC2_MASTER_OVERFLOW"
tdsread C1:SUS-MC1_MASTER_OVERFLOW C1:IOO-MASTER_OVERFLOW C1:SUS-MC2_MASTER_OVERFLOW
op440m:WFS>



This is the same bug described in entry 180. I believe it has nothing to do with tdsread, which did not change in the time period before the bug appeared, but perhaps has something to do with other EPICS libraries somewhere (tdsread relies on these epics libraries to do its dirty work). Here is entry 180 for reference:


Quote:
tdsread has developed a strange new illness, whereby it cannot read EPICS values from two subsystems at once (e.g., getting an LSC and SUS value simultaneously). I thought this might have something to with the fact that both losepics and iscepics are running on the same box,
but the same thing happens with IOO EPICS records, so that's not the culprit.

This is new behaviour, and it's only happening on the solaris machines. I suspect some ENV/cshrc juju has caused it, as the tdsread executable is the same one from April, and I don't think our EPICS infrastructure has changed otherwise. In the near term we can either try running the scripts on linux, or modify the IFO scripts to not do these types of calls.


The solution that's been in effect for the past few months has just been to modify the scripts to not make these kinds of calls.
  435   Tue Apr 22 10:59:24 2008 robUpdateSUSMC1 electronics busted

Quote:
I spent some time trying to fix the utter programming fiasco which was our MCWFS diagonalization script.

However, it still didn't work. Loops unstable. Using the matrix in the screen snapshot is OK, however.

Finally, I realized from looking at the imaginary part of the output matrix that there was something
wrong with the MC1 drive. The attached JPG shows TFs from pit-drives of the MC mirrors to WFS1.

MC1 & MC3 are supposed to have 28 elliptic low pass filters in hardware for dewhitening. The MC2
hardware is different and so we have given it a software 28 Hz ELP to compensate. But it looks like
MC1 doesn't have the low pass (no phase lag). I tried switching its COIL FM10 filters to make it
switch but no luck.

We'll have to engage the filters to make the McWFS work right and to get the MC noise down. This
needs someone to go check out the hardware I think.

I have turned the gain way down and this has stabilized the MC REFL signal as you can see from the StripTool screen.


This was just because the XYCOM was set to switch the "dewhites" based on FM9 rather than FM10. To check whether the hardware ellipDW filters were engaged, I drove MC1 & MC3 in position (using the MCL bank), and looked at the transfer functions MC2_MCL/MC1_MCL and MC2_MCL/MC3_MCL. This method uses the mode cleaner length servo to enable a relatively clear transfer function measurement of the ellipDW, modulo the loop gain of MCL and the fact that it's really hard to measure an ELP cascaded with a suspension. The hardware and the switching appear to be working fine.

It's now set up such that the hardware is ENGAGED when the coil FM10 filters are OFF, and I deleted all the FM10 filters from the coils of MC1 and MC3. Since we don't switch these filters on and off regularly, I see no need to waste precious SUS processor power on filters that just calculate "1".
  436   Tue Apr 22 16:17:48 2008 robUpdateSUSend station sus front-end bug fix

Quote:
installed and started new susEtmx.o and susEtmy.o to fix a problem with ETMY optical lever variables.


What Alex means is that the EPICS values for the ETMY optical levers were being clobbered in the RFM. The calculations were being done correctly in the FE, so the DAQ/testpoints were working--it was just the EPICS/RFM communication via c1losepics that was bugged. This was a result of the recent SUS code changes to accept inputs from the ASS for adaptive feedforward.
  437   Tue Apr 22 17:08:04 2008 CarynUpdateIOOno signal for C1:IOO-MC_L
C1:IOO-MC_L signal was at zero for the past few days
  442   Thu Apr 24 14:10:26 2008 robUpdateLockinglocking work
Rob, Johnnie

We made some progress on locking last night (Wed night), namely that we were able to handoff (briefly) the CARM-MCL path the REFL-DC error signal. We tried this because we suspect that the reason the PO-DC is not a good CARM error signal is because at low powers, the dc light level in the recycling cavity is dominated by the +f2 RF sideband. Thus, REFL-DC should work a bit better at low powers, which it did. It wasn't super stable, though, so this will require a bit of work to make the transition reliable & stable. The next things to work on include setting the AO path gain properly and possibly going to higher arm powers before handing off (thus increasing the discriminant).

Another thing we found is that the alignment scripts are not working in an ideal fashion. Running the alignment scripts for the two arms (XARM & YARM) leaves the Michelson badly misaligned, making it impossible to get good DRM alignment. This will have to be fixed.
  445   Thu Apr 24 23:27:48 2008 ranaUpdatePEMacoustic noise in MC_F
I looked at the coherence between the Microphone in the PSL (PEM-AS_MIC) and the MC_F channel.

We want to use a microphone to do Wiener/Adaptive noise cancellation on the MC and so we need to
have a coherence of more than ~0.1 in order for that to have any useful effect.

The attached plot shows the spectrum and coherence with and without the HEPA turned up. As you can
see, the HEPA noise is just barely noticeable in this microphone. Mad

We will need to get something with at least 20 dB more sensitivity.:P
  446   Thu Apr 24 23:50:10 2008 ranaUpdateGeneralSyringes in George the Freezer
There are some packets of syringes in the freezer which are labeled as belonging to an S. Waldman.
Thu Apr 24 23:48:55 2008

Be careful of them, don't give them out to the undergrads, and just generally leave them alone. I
will consult with the proper authorities about it.
  448   Fri Apr 25 13:20:04 2008 AndreyUpdatePEMMicrophone test
In response to Rana's request, I tested the microphone (if it is alive or not) by clapping my hands and speaking aloud nearby.

The microphone is alive, see the attached "Full Data" for 5 minutes from Dataviewer.
  450   Fri Apr 25 15:44:21 2008 steveUpdatePSLscattering measurments
In pursuit of a low back scattering, high power beam dump we looked at materials such:
polished copper, polished aluminum, diamond cut aluminum, variety of polished & heat treated stainless steel and shades of black glasses.
Black glass is ideal at low power. Superpolished SS 304 #8 is the only material that measures close to bg
We are still looking for a conductive low back scattering material that would be ideal for a good high power beam trap.

Black glass-shade 12, ss304 superpolished #8 and white paper-B98-24lbs back scattering were compared at 1064 nm

Atm 1: data plot numbers from front panel of SR830 display,
sensitivity: 1x1 mV for bg and ss
1x1 V for wp

Atm 2: drawing of measurement set up
Atm 3: SR830 lock.amp settings
Atm 4: view from steering mirror
Atm 5: view from black glass trap
Atm 6: white paper
  458   Mon Apr 28 23:44:33 2008 AndreyUpdateComputer Scripts / ProgramsWeather.db

I was trying to figure out how to modify the file "Weather.db" so that the atm.pressure would be recalculated from Pa to bar before appearing in the EPICS screen, but so far I did not succeed. I restarted processor "c1pem1" several times. I will continue this tomorrow, and also I will modify the nmaes of the weather channels.
  460   Tue Apr 29 21:30:49 2008 AndreyUpdatePEMIn the process of renaming channels for Weather Station

I startted renaming channels for the weather station, and I will continue this tomorrow, on Wednesday.

I have restarted 'c1pem1' several times and reconfigured "C0DCU1" on the framebuilder MEDM screen.

Framebuilder now does not work.
  462   Thu May 1 08:31:51 2008 steveUpdateSUSearthquake trips etmy & mc1
Earthquake at Lake Isabel magnitude 4.4 at 1am today shakes the 40m
ETMY and MC1 watchdogs tripped.
Sus damping restored.
  465   Mon May 5 15:53:14 2008 steveUpdateVACdrypump replaced & readbacks are out
The small turbo pump of the annulus system is tp3
It's drypump was replaced at 1.4 Torr after 8 months of operation.
The rebuilding cost of this SH100 drypump is getting ridiculously high $1349.
I'll look for a replacement.

Joseph rebooted c1vac2 card on Apr 24 entry#441
This restarted the readbacks of the turbos and ion pumps for a while.
That was nice. The readbacks are not working again

  472   Fri May 9 08:40:24 2008 steveUpdateSUSETMY sus damping restored
ETMY lost damping at 19:10 last night.
There was no seismic event than.
Sus damping was restored this morning.
  473   Fri May 9 10:15:36 2008 josephbUpdateComputersNodus has moved
Steve and myself moved Nodus from under the table in the control room, to just above the Rana computer in the control room rack.
  474   Tue May 13 10:15:52 2008 steveUpdateSUSrestored damping of BS & PRM
I think our janitor was cleaning too heavy handedly.
The BS and PRM sus damping were lost.
They were restored.
  475   Tue May 13 10:38:28 2008 steveUpdateComputersrfm network is down
The RFM network went down yesterday around 5pm
Only c1susvme1 is alive but it's timing is off.
Andrey is bringing the network up.

Andrey wants to make an addition first that our situation is very much similar to that described by Rana in his elog entry # 353 (March 03). All of the rectangular boxes are red, except for SUS1-c1susvme1 and AWG (only these two rectangles are green).
  477   Wed May 14 14:05:40 2008 AndreyUpdateComputersComputer Linux-2, MEDM screen "Watchdogs"

Computer "Linux-2", MEDM screen "C1SUS_Watchdogs.adl": there is no indication for ETMY watchdogs, everything is white. There is information on that screen "C1SUS_Watchdogs.adl" about all other systems (MC, ETMX,...), but something is wrong with indicators for ETMY on that particular control computer.
  487   Mon May 19 11:49:57 2008 steveUpdateSUSetmy oplev laser replaced
The 9 years old Uniphase HeNe was replaced by a new JDSU 1103P
Power output ~3.5 mW, reflected light back on qpd ~140 microW, 12,800 counts
Andrey will get the ~2.5 mm od spot on the qpd smaller by replacing
the f1000 lens
  490   Wed May 21 15:21:33 2008 robUpdateComputer Scripts / Programsautolockers and cron

I added hourly cron jobs to op340m to ensure that

MC autolocker
FSS Slow Servo
PSL watch

are running. I've also edited the wiki procedure to reflect the fact that these no longer need to be restarted by hand.
  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.
  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.
  502   Wed May 28 14:19:47 2008 steveUpdatePSLkaleidoscope of psl
atm 1: scattering psl table optics from the top of the output periscope f4, 60s @MOPA 3 W
atm 2: scattering psl table optics from the top of the output periscope f4, 20s
atm 3: competing GigE cameras on the north end of psl table
atm 4: yellow "soft" washer to be replaced on psl output periscope
atm 5: ETMY-ISCT in disarray
  504   Thu May 29 16:32:09 2008 steveUpdateSUSetmy oplev is back
I relayed the optics for ETMY-oplev as shown in pictures below.
The reflected beam goes directly to the qpd
  507   Fri May 30 12:37:45 2008 robUpdateSUSetmy oplev is back

Quote:
I relayed the optics for ETMY-oplev as shown in pictures below.
The reflected beam goes directly to the qpd


I turned on the servo. UGFs in PIT and YAW are ~3Hz. I had to flip the sign of the YAW.
  515   Tue Jun 3 12:33:36 2008 AndreyUpdateCamerasAndrey, Josephb

Continuing our work with cameras,

1) we removed both cameras from their places on Monday afternoon, and were taking the beam-scans with a special equipment (see elog-entry 511) from Bridge bld.,

2) and on Tuesday morning we putted back the GC-750 camera into the transmitted beam path, camera GC-650 into the reflected beam path. We plan to compare the images from the "reflection camera" for several different angles of tilt of the camera.
  516   Wed Jun 4 10:18:52 2008 steveUpdatePSLwedged SS beam trap
I moved the SS trap over to the psl table.
Texas super # 8 was used from the large shipment.
TXs#8 scattering measured as before, meaning the polishing is good.

Go's squeezing power pick up 350 mW was used.
I made two ~30 degrees wedge traps using 6" x 4" and 12" x 4" SS 0.039" thick
with copper backing of similar size.

There was too much scattering and I could not minimize them all.
It is very helpful to have so much space on the psl table.
It shows more of the weakness of this kind of trap.
I did not dare to turn up the power.
  524   Fri Jun 6 16:10:51 2008 steveUpdatePSLHEPA filters are running at 100%
The psl HEPA filters were turned up to run at 100% to accommodate beam trap work on Tuesday, June 3, 2008
  528   Tue Jun 10 08:37:18 2008 steveUpdatePSLbeam trap is being tested
High power beam trap is being tested just west of FSS area on psl enclosure.

When the pmc is operating at low power that means that the rest of the 3W is going into the
circular SS trap.

Please beware of the high power beam trap test
  529   Wed Jun 11 11:45:25 2008 steveUpdatePSLss trap works
The trap works well at 3 W level. No back reflected beam coming out of the trap on low power
sensing card level. The back scattering was not measured. The trap is insensitive to small pointing variations.
The SS surface did not show any visible degradation after 16 hrs of 3w exposure at elliptical beam size 4x8 mm

It is ready to be placed into the 35 W beam.
  531   Thu Jun 12 01:51:23 2008 robUpdateLockingreport
rob, john

We've been working (nights) on getting the IFO locked this week. There's been fairly steady incremental progress each night, and tonight we managed to control CARM(MCL) using PO-DC, with the CARM(AO) path also on PO-DC. In the past, reaching this state has usually meant we're home free, as we could just crank the gain on the common mode servo and merrily reduce the CARM offset. Tonight, however, this state has been very twitchy, and efforts to ramp up the gain have been unsuccessful.

I've attached a diagram which I hope makes clear where we are in the stages of lock acquisition.
  532   Thu Jun 12 15:09:33 2008 alanUpdateLockingreport
Rob: Awesome figure. As you can imagine, I have lots of questions, and hope that you will consider this figure to be the beginning, leading to ever-more detailed versions. But for now, I just want to ask whether you understand *what* is twitchy, and what the twitchiness does to prevent you from taking this further?
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