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ID Date Author Type Category Subject
  2166   Sun Nov 1 17:58:44 2009 JenneUpdateGeneralUpdate on Video Switch

The current update on the Chameleon video switch is: no progress.

I connected the old laptop that Rob/Steve acquired via RS-232 serial to the back of the video switch.  I'm using P2, the same serial port that the C1AUX computer was connected to just in case there's something good about P2 vs. P1. 

I used HyperTerminal to (try to) talk to the switch.  Settings were:  COM1, bits per second = 9600, data bits = 8, parity = none, stop bits = 1, flow control = none.  I can successfully send/get back responses to the basic commands, I (inquiry as to the type of equipment), and H (help - spits out the list of acceptable commands).  But when I try to do an actual command to do some video switching, everything hangs.  The front panel's rolling display (which just echos the company name) stops, then starts up again after ~20sec.  The hyperterminal display doesn't change.  I get neither the "DONE" answerback, which would indicate that the command executed successfully, nor do I get the "ERROR" answerback, which would indicate that something is wrong.  It just hangs.  If I disconnect, and restart the connection, and instead of trying a real command, but instead just send 'blahblahblah', then it will answerback 'ERROR' the first time, and then if I try to send another garbage message, everything hangs again.  So, I can sort of talk to the video switch, but I can't make it do anything yet.

I'm leaving the laptop connected instead of C1AUX, since the video EPICS screen doesn't work anyway for now.  If you want to start up the connection, either input the settings quoted above, or open "40m Video", which should have these connection settings saved in HyperTerminal.

  2165   Fri Oct 30 10:52:56 2009 JenneUpdatePSLHEPAs

Zach found the HEPA switch on the PSL table OFF.  He turned them on.

  2164   Fri Oct 30 09:24:45 2009 steveHowToMOPAhow to squeeze more out of little

Quote:

Here is the plots for the powers. MC TRANS is still rising.

What I noticed was that C1:PSL-FSS_PCDRIVE nolonger hit the yellow alert.
The mean reduced from 0.4 to 0.3. This is good, at least for now.

 Koji did a nice job increasing light power with some joggling.

Attachment 1: 44to34.jpg
44to34.jpg
  2163   Fri Oct 30 04:41:37 2009 robUpdateLockingworking again

I never actually figured out exactly what was wrong in entry 2162, but I managed to circumvent by changing the time sequence of events in the up script, moving the big gain increases in the common mode servo to the end of the script.  So the IFO can be locked again.

  2162   Thu Oct 29 21:51:07 2009 robUpdateLockingbad

Quote:

Quote:

Lock acquisition has gone bad tonight. 

The initial stage works fine, up through handing off control of CARM to MCL.  However, when increasing the AO path (analog gain), there are large DC shifts in the C1:IOO-MC_F signal.  Eventually this causes the pockels cell in the FSS loop to saturate, and lock is lost. 

 This problem has disappeared.  I don't know what it was. 

The first plot shows one of the symptoms.  The second plot is a similar section taken from a more normal acquisition sequence the night before.

All is not perfect, however, as now the handoff to RF CARM is not working.

 

The problem has returned.  I still don't know what it is, but it's making me angry. 

Attachment 1: itsback.png
itsback.png
  2161   Thu Oct 29 20:21:14 2009 KojiUpdatePSLNPRO LTMP lowered 9.5deg

Here is the plots for the powers. MC TRANS is still rising.

What I noticed was that C1:PSL-FSS_PCDRIVE nolonger hit the yellow alert.
The mean reduced from 0.4 to 0.3. This is good, at least for now.

Attachment 1: PSL_MC.png
PSL_MC.png
  2160   Thu Oct 29 18:25:33 2009 SanjitUpdateAdaptive FilteringMore work on saving coeffs on the OAF screen

Quote:

[Sanjit,Jenne]

Sanjit has been working today on trying to get the OAF coefficients to save properly.  Alex got us most of the way, but right now it's looking like the filter that is being saved is totally constant (all the values are the same).  We're poking around trying to figure out why this is. 

Also, we're starting again (as we should have been for the last week or so since Alex came in to help us) to check in the TOP_XFCODE whenever we make changes to it, and when we recompile the front end code. 

 

We are manually restarting assepics, but the terminal logs us out after sometime and ass may crash. I set autologout=0 in the terminal for the time being. Once the testing process is over, assepics will start automatically when the computer is turned on, so we wont have to worry about this.

(if ass crashes tonight, it is not unexpected!)

 

  2159   Thu Oct 29 18:04:02 2009 JenneUpdateAdaptive FilteringMore work on saving coeffs on the OAF screen

[Sanjit,Jenne]

Sanjit has been working today on trying to get the OAF coefficients to save properly.  Alex got us most of the way, but right now it's looking like the filter that is being saved is totally constant (all the values are the same).  We're poking around trying to figure out why this is. 

Also, we're starting again (as we should have been for the last week or so since Alex came in to help us) to check in the TOP_XFCODE whenever we make changes to it, and when we recompile the front end code. 

  2158   Thu Oct 29 13:48:32 2009 KojiUpdatePSLNPRO LTMP lowered 9.5deg

13:00 Found MC TRANS less than 7.
13:50 Go into the PSL table.
14:20 Work done. Now I am running SLOWscan script.
15:10 SLOWscan finished. It was not satisfactory. I go into the table again.
15:15 Running SLOWscan again.
16:00 SLOWscan done. Lock PMC. Adjust NPRO current so as to maximize PMC TRANS.
16:10 Lock RC, PMC, MZ, MC. Align PMC / MZ on the table. Align MC WFS beams on the QPDs.
16:30 Work done.

New FSS-SLOWDC nominal is -4.0

Now MC TRANS is 7.9. This is +12% increase. ENJOY!
HEPA is on at 90%. Light is off.

---------

NPRO TEMP trimmer adjustment
o PSL NPRO TEMP trimmer at the back of the laser head was turned 6.5 times in CW.
o It reduced NPRO crystal temp by 9.5deg. (43.5deg -> 34.0deg for FSS_SLOWDC -5.5)

To revert the previous setting, refer to the former measurement
c.f. http://nodus.ligo.caltech.edu:8080/40m/2008

NPRO Thermal scan
o 2 scans are performed.
o I selected the colder side of the second scan. i.e. SLOWDC=-4.0

NPRO Current adjustment
o Tweaked C1:PSL-126MOPA_126CURADJ while looking at PMC TRANS.
o CURADJ was changed from -2.25 to -1.9. This corresponds to change of C1:PSL-126MOPA_CURMON from 2.503A to 2.547A.

Attachment 1: 091028_PSL.png
091028_PSL.png
  2157   Wed Oct 28 17:20:21 2009 ranaSummaryCOCETM HR reflectivity plot

This is a plot of the R and T of the existing ETM's HR coating. I have only used 1/4 wave layers (in addition to the standard 1/2 wave SiO2 cap on the top) to get the required T.

The spec is a T = 15 ppm +/- 5 ppm. The calculation gives 8 ppm which is close enough. The calculated reflectivity for 532 nm is 3%. If the ITM reflectivity is similar, the signal for the 532 nm locking of the arm would look like a Michelson using the existing optics.

etm_40_1998.png

  2156   Wed Oct 28 14:39:10 2009 steveUpdatePEMafter the tour of the 40m
Illuminators and PSL lights turned off.
HEPA filter speed increased from 20 to 100%
  2155   Wed Oct 28 09:12:18 2009 steveUpdatePSLPMC power on the rise?

The PMC power is seems to be on the rise, ( MOPA_AMPMON is dropping ?) but I do not think it is real. We have Santa Anna wind condition, when the relative humidity drops and  ......

There is an other funky think. The room temp became rock solid. The PSL HEPAs running at 20% and IFO-room ACs are also in normal operational mode.

Attachment 1: pmcprising.jpg
pmcprising.jpg
  2154   Wed Oct 28 05:02:28 2009 robUpdateLockingback

LockAcq is back on track, with the full script working well.  Measurements in progress.

  2153   Tue Oct 27 19:37:03 2009 kiwamuUpdateLSCcron job to diagnose LSC-timing

I set a cron job on allegra.martian to run the diagnostic script every weekend.

I think this routine can be helpful to know how the trend of timing-shift goes

The cron runs the script on every Sunday 5:01AM and diagnostics will take about 5 min.

 

! Important:

During the running of the script, OMC and DARM can not be locked.

If you want to lock OMC and DARM in the early morning of weekend, just log in allegra and then comment out the command by using 'crontab -e'

 

 

  2152   Tue Oct 27 18:19:14 2009 robUpdateLockingbad

Quote:

Lock acquisition has gone bad tonight. 

The initial stage works fine, up through handing off control of CARM to MCL.  However, when increasing the AO path (analog gain), there are large DC shifts in the C1:IOO-MC_F signal.  Eventually this causes the pockels cell in the FSS loop to saturate, and lock is lost. 

 This problem has disappeared.  I don't know what it was. 

The first plot shows one of the symptoms.  The second plot is a similar section taken from a more normal acquisition sequence the night before.

All is not perfect, however, as now the handoff to RF CARM is not working.

Attachment 1: MCF_issue.png
MCF_issue.png
Attachment 2: no_MCF_issue.png
no_MCF_issue.png
  2151   Tue Oct 27 18:01:49 2009 robUpdatePSLhmmm

A 30-day trend of the PCDRIVE from the FSS.

Attachment 1: pcdrive_trend.png
pcdrive_trend.png
  2150   Tue Oct 27 17:58:25 2009 JenneConfigurationPEMUnknown PEM channels in the PEM-ADCU?

Does anyone know what the channels plugged in to the PEM ADCU, channels 5,6,7,8 are?  They aren't listed in the C1ADCU_PEM.ini file which tells the channel list/dataviewer/everything about all the rest of the signals which are plugged into that ADCU, so I'm not sure if they are used at all, or if they're holdovers from some previous time.  The cables are not labeled in a way that makes clear what they are.  Thanks!

  2149   Tue Oct 27 15:55:04 2009 KojiUpdateGeneralISS injection work / HEPA is on

I was working on the ISS excitation to take TFs.

I used ISS IL excitation, stealing from a small box on the floor for the OMC.

All the configuration was restored except that the HEPA is on.

  2148   Tue Oct 27 01:45:02 2009 robUpdateLockingMZ

Quote:
Tonight we also encountered a large peak in the frequency noise around 485 Hz. Changing the MZ lock point (the spot in the PZT range) solved this.


This again tonight.

It hindered the initial acquisition, and made the DD signal handoff fail repeatedly.
  2147   Mon Oct 26 23:14:08 2009 KojiUpdatePSLlaser power is down

I adjusted the steerings to the PMC and gained 7%. Now the MC_TRANS 7.0 has been recovered.

Actually I need another 7% to get MC_TRANS 7.5.
But I couldn't find how I can recover 126MOPA-AMPMON to 2.8ish.

Quote:

The laser power is down 5-6%

 

Attachment 1: PSL091026.png
PSL091026.png
  2146   Mon Oct 26 19:12:50 2009 kiwamuUpdateLSCdiagnostic script for LSC timing

The diagnostic script I've written is available in the 'caltech/users/kiwamu/work/20091026_OMC-LSC-diag/src'.

To run the script, you can just execute 'run_OMC_LSC.sh' or just call the m-file ' OMC_LSC_timinig.m'  from matlab.

 

NOTES:

The script destructs the lock of DARM and OMC, be careful if you are working with IFO.

  2145   Mon Oct 26 18:49:18 2009 kiwamuUpdateLSCOMC-LSC timing issue

According to my measurements I conclude that LSC-signal is retarded from OMC-signal with the constant retarded time of 92usec.
It means there are no timing jitter between them. Only a constant time-delay exists.

(Timing jitter)
Let's begin with basics.
If you measure the same signal at OMC-side and LSC-side, they can have some time delay between them. It can be described as followers.

exp1.png
where tau_0 is the time delay. If the tau_0 is not constant, it causes a noise of the timing jitter.

(method)
I have injected the sine-wave with 200.03Hz into the OMC-LSC_DRIVE_EXC. Then by using get_data, I measured the signal at 'OMC-LSC_DRIVE_OUT' and 'LSC-DARM_ERR' where the exciting signal comes out.
In the ideal case the two signals are completely identical.
In order to find the delay, I calculated the difference in these signals based on the method described by Waldman. The method uses the following expression.
exp2.png
Here the tau_s is the artificial delay, which can be adjusted in the off line data.
By shifting tau_s we can easily find the minimal point of the RMS, and at this point we can get tau_0=tau_s.
This is the principle of the method to measure the delay.  In my measurement I put T=1sec. and make the calculation every 1sec. in 1 min.


(results)
Attachment is the obtained results. The above shows the minimum RMS sampled every 1sec. and the below shows the delay in terms of number of shifts.
1 shift corresponds to Ts (=1/32kHz).  All of the data are matched with 3 times shift, and all of the minimum RMS are completely zero.
Therefore I can conclude that LSC-signal is retarded from OMC-signal with constant retarded times of 3*Ts exactly, and no timing jitter has been found.
 

Attachment 3: OMC_LSC60sec.png
OMC_LSC60sec.png
  2144   Mon Oct 26 18:15:57 2009 robUpdateIOOMC OLG

I measured the mode cleaner open loop gain.  It's around 60kHz with 29 degs of phase margin.

  2143   Mon Oct 26 17:45:34 2009 JenneUpdateAdaptive FilteringNew changes to the OAF fe code

[Alex, Jenne, Sanjit]

Alex came to the 40m today, and did several awesome things in OAF-land.

We discovered that there is, in fact, an ADC board connected to the ASS machine.  The tricky bit is that it only has a ribbon cable connector, so before we can use this ADC, we need to figure out how to make a breakout board/cable/something to connect the seismometer/accelerometer/microphone BNCs to this little board.  This is the same little board that connects the timing slave to the ASS machine.  For good or for ill, the timing slave is connected to this board via clip-doodles.  Potentially we can connect an ADC tester board to this board, and go from seismometer BNCs to clipdoodles to the tester board, but I'm not in love with the idea of utilizing clipdoodles as a semi-permanent solution until the upgrade.  I emailed Ben to see if he has a better idea, or (better yet) some spare hardware now that's the same as we'll use after the upgrade.  If we can use this ADC, it may solve our timing problem which is caused by the 110B ADC used by the PEM computer. Alex showed Sanjit and I how to connect the ASS's ADC card to the simulink diagram, when we're ready for that.

We also poked around in the code, and it seems that we can now save and restore OAF coefficients at will.  I added buttons to the OAF (ASS) screen, and Alex made it so the OAF coefficients are saved in RFM shared memory whenever you click the "save coeffs" button, and are restored when you click the "restore coeffs" button.  The buttons are the same as the 'Reset' button which has been there for a long time, so they seem to maybe have a similar problem in that you have to hold the button for a while in order for the code to realize that the button has been depressed.  We couldn't fix this easily, because it looks like our SimuLink cds stuff is a little out of date.  Some day (before/when Joe and Peter make new screens for the new 40m), we need to update these things.  Alex was concerned that it might take a while to do this, if the update broke some of the blocks that we're currently using.  Also, Sanjit and I now need to check that the coefficient-saving is going as planned.  When I have DTT open, and the OAF running, I see a certain shape to the signal which is sent to MC1 to correct for the seismic motion.  This shape includes at least several peaks at resonant frequencies that exist in our stacks/suspensions.  I can then save the coefficients, reset the active filter, and then restore the coefficients.  When I do this while watching DTT, it seems as though the general shape of the filter is restored, but none of the detailed features are.  The reason for this is still under investigation. 

The code-modifications involved a few iterations of 'remaking the ass'.

  2142   Mon Oct 26 15:40:01 2009 steveUpdatePSLlaser power is down

The laser power is down 5-6%

Attachment 1: laserpowerdown.jpg
laserpowerdown.jpg
  2141   Mon Oct 26 03:57:06 2009 robUpdateLockingbad

Lock acquisition has gone bad tonight. 

The initial stage works fine, up through handing off control of CARM to MCL.  However, when increasing the AO path (analog gain), there are large DC shifts in the C1:IOO-MC_F signal.  Eventually this causes the pockels cell in the FSS loop to saturate, and lock is lost. 

  2140   Sun Oct 25 14:29:45 2009 haixing, kiwamuConfigurationGeneralSR785 spectrum analyzer

In this morning, we have disconnected SR785 which was in front of 1X2 rack, to measure a Hall sensor noise.

After a while, we put back SR785 and re-connected as it has been.

But the display setup might have been changed a little bit.

 

  2139   Sat Oct 24 04:57:33 2009 ranaUpdateloremarconi phase

Quote:

So, it appears that one doesn't even have to change the Marconi set frequency to alter the phase of the output signal.  It appears that other front panel actions (turning external modulations on/off, changing the modulation type) can do it as well.  At least that's what I conclude from earlier this morning, when after setting up the f2 Marconi (166MHz) for external AM, the double-demod handoff in the DRMI no longer worked.  Luckily this isn't a real problem now that we have the setDDphases and senseDRM scripts. 

 The real problem is that we are using frequency synthesizers to make the beat signals (133 and 199) instead of mixers. Luckily, the future 40m will not use beat signals (?) or synthesizers.

  2138   Fri Oct 23 15:02:00 2009 robUpdateloremarconi phase

So, it appears that one doesn't even have to change the Marconi set frequency to alter the phase of the output signal.  It appears that other front panel actions (turning external modulations on/off, changing the modulation type) can do it as well.  At least that's what I conclude from earlier this morning, when after setting up the f2 Marconi (166MHz) for external AM, the double-demod handoff in the DRMI no longer worked.  Luckily this isn't a real problem now that we have the setDDphases and senseDRM scripts. 

  2137   Fri Oct 23 09:13:45 2009 steveSummaryVACRGA scan

Pump down #66 is 435 days old. RGA scan is normal. New maglev is fine. New UPS is in place but not hooked up to communicate.

V1 has bare minimum interlock. Pirani vacuum gauges  PTP1 and PRP do not communicate with readout system.

There is no emergency dial out in case of vacuum loss.  Our existing vacuum dedicated desk top computer is dead.

New cold cathodes, Pirani gauges and gauge controller should be added.

In general: vacuum system needs an upgrade !

 

Attachment 1: pd66md435.jpg
pd66md435.jpg
Attachment 2: pd66d435ptt.jpg
pd66d435ptt.jpg
  2136   Thu Oct 22 23:14:54 2009 ZachUpdateWIKI-40M UpdatePSL Table Diagram wiki entry

Quote:

Diagram. I don't want to say PNG is an editable format for this purpose...
You have the PPT, PDF or any drawing format to create this diagram.

Quote:

http://lhocds.ligo-wa.caltech.edu:8000/40m/PSL_Table_Diagram

Thanks. I love this. Could you also put the original file that is editable for future modification by anyone?

 Do you mean the diagram or the inventory? The diagrams are online as attachments (small versions on the main "PSL Table Diagram" page and large versions on the linked pages). The inventory is easily editable on the wiki itself. It's just rendered in table form using the CSV parse utility for "comma-separeted values" (though you actually need to use semicolons, for reasons unknown).

 

 

Good news and bad news. For the MOPA diagram, which I did recently, I have GIMP file with separate layers for the background image, ray traces, and labels. Unfortunately, I didn't realize that this was the best way to do it until I had done most of the ray tracing for the main diagram, so, although I have that file in GIMP as well, only the labels are on a separate layer. If this is a major issue I can do the tracing again. The other thing is that the original files are quite large: 17.3 MB for the MOPA, and 64.1(!) MB for the main diagram. Let me know what you think.

  2135   Thu Oct 22 21:58:26 2009 KojiUpdateWIKI-40M UpdatePSL Table Diagram wiki entry

Diagram. I don't want to say PNG is an editable format for this purpose...
You have the PPT, PDF or any drawing format to create this diagram.

Quote:

http://lhocds.ligo-wa.caltech.edu:8000/40m/PSL_Table_Diagram

Thanks. I love this. Could you also put the original file that is editable for future modification by anyone?

 Do you mean the diagram or the inventory? The diagrams are online as attachments (small versions on the main "PSL Table Diagram" page and large versions on the linked pages). The inventory is easily editable on the wiki itself. It's just rendered in table form using the CSV parse utility for "comma-separeted values" (though you actually need to use semicolons, for reasons unknown).

 

  2134   Thu Oct 22 15:49:29 2009 ZachUpdateWIKI-40M UpdatePSL Table Diagram wiki entry

Quote:

http://lhocds.ligo-wa.caltech.edu:8000/40m/PSL_Table_Diagram

Thanks. I love this. Could you also put the original file that is editable for future modification by anyone?

Quote:

 I made a wiki entry for the PSL table diagram under the PSL directory on the 40mHomePage. I tried to use the ImageLink macro to use a resized (smaller) version of the diagram as a link to the full image, which it is designed to do if there is no target given, but it didn't seem to work. Instead, I had to create a second page that had the full-sized diagram, and I used ImageLink with a smaller version to link to that page.

The inventory that is shown is clearly incomplete. Part of this is due to the fact that many labels were either missing or impossible to read without touching stuff. For those components with labels missing, I tried to infer what they were to the best of my knowledge, but I wasn't able to for all of them. In true wiki spirit, everyone is encouraged to fill in any additional information they might have on these components. 

 

 Do you mean the diagram or the inventory? The diagrams are online as attachments (small versions on the main "PSL Table Diagram" page and large versions on the linked pages). The inventory is easily editable on the wiki itself. It's just rendered in table form using the CSV parse utility for "comma-separeted values" (though you actually need to use semicolons, for reasons unknown).

  2133   Thu Oct 22 15:44:16 2009 ZachUpdateWIKI-40M UpdateMOPA diagram

 I have updated the PSL Diagram wiki page to include MOPA. As with the PSL diagram, clicking the photo on the main page takes you to a larger image. The inventory is pretty meager as I didn't have time to sit and read labels (if indeed there are any). I will look through the documentation at the 40m to see if there is a record of what is there. Again, if you know something, please amend the list!!

http://lhocds.ligo-wa.caltech.edu:8000/40m/PSL_Table_Diagram

  2132   Thu Oct 22 08:45:58 2009 steveUpdateIOOIP ang & pos recentered

Quote:

Pointing stability of 4 days. Initial pointing does not go through suspended optics. It is launched  right after the Piezo Jena steering mirrors in the BS chamber.

IP-ANG on epics screen is  C1:ASC-IBQPD_X and Y in dataviewer  were recentered. This beam is clipping a bit in ETMX chamber  pick off mirror.

IP-POS pick  off is in the BS chamber and it's qpd on the BS_ISCT This beam is also clipping just a little bit. This is easy to fix. We'll have to remove an iris from the BS optical levers table.

note: arms were not locked when I recentered

 IP-ANG clipping can be traced back to our last vent of Aug. 18, 2008  See elog entry #845

This was an after earth quake - sus repair vent

Attachment 1: pointing1000.jpg
pointing1000.jpg
  2131   Wed Oct 21 17:12:30 2009 AlbertoUpdateelogBrowser context menu enabled on the Elog under HTM editing mode

On behalf of Steve and of the rest of the not-native-English community at the 40m willing to have their browser's spell checker working while editing the Elog, I fixed the Elog's feature that prevented Firefox' context menu (that one which pops up with a mouse right click) to work when using the HTML editing interface (FCKeditor).

That let also Firefox spell checker to get enabled.

To get the browser context menu just press CTRL right-clicking.

To make sure that the features works properly on your browser, you might have to fully clear the browser's cache.

Basically I modified the FCKeditor config file (/cvs/cds/caltech/elog/elog-2.7.5/scripts/fckeditor/fckconfig.js). I added this also to the elog section on our Wiki.

  2130   Wed Oct 21 16:18:12 2009 SteveSummarySAFETYLIGO Safety Officers visited the 40m

David Nolting, chief LIGO Safety Officer and his lieutenants from LLO and LHO paid homage to the 40m lab this morning.

They give us a few recommendation: update safety documents, move optical table from the front of ETMX-rack and label-identify absorbent plastics on enclosure windows-doors.

We'll correct these short comings ASAP

 

  2129   Wed Oct 21 15:07:45 2009 AlbertoUpdateWIKI-40M UpdatePhotodiodes' configuration for the Upgrade

I uploaded on the Wiki (here) the results of an inventory over our current PDs, a list of the new ones that we're going to need for the new control scheme.

  2128   Wed Oct 21 13:07:54 2009 KojiUpdateWIKI-40M UpdatePSL Table Diagram wiki entry

http://lhocds.ligo-wa.caltech.edu:8000/40m/PSL_Table_Diagram

Thanks. I love this. Could you also put the original file that is editable for future modification by anyone?

Quote:

 I made a wiki entry for the PSL table diagram under the PSL directory on the 40mHomePage. I tried to use the ImageLink macro to use a resized (smaller) version of the diagram as a link to the full image, which it is designed to do if there is no target given, but it didn't seem to work. Instead, I had to create a second page that had the full-sized diagram, and I used ImageLink with a smaller version to link to that page.

The inventory that is shown is clearly incomplete. Part of this is due to the fact that many labels were either missing or impossible to read without touching stuff. For those components with labels missing, I tried to infer what they were to the best of my knowledge, but I wasn't able to for all of them. In true wiki spirit, everyone is encouraged to fill in any additional information they might have on these components. 

 

  2127   Wed Oct 21 11:41:29 2009 ZachUpdateWIKI-40M UpdatePSL Table Diagram wiki entry

 I made a wiki entry for the PSL table diagram under the PSL directory on the 40mHomePage. I tried to use the ImageLink macro to use a resized (smaller) version of the diagram as a link to the full image, which it is designed to do if there is no target given, but it didn't seem to work. Instead, I had to create a second page that had the full-sized diagram, and I used ImageLink with a smaller version to link to that page.

The inventory that is shown is clearly incomplete. Part of this is due to the fact that many labels were either missing or impossible to read without touching stuff. For those components with labels missing, I tried to infer what they were to the best of my knowledge, but I wasn't able to for all of them. In true wiki spirit, everyone is encouraged to fill in any additional information they might have on these components. 

  2126   Tue Oct 20 16:35:24 2009 robConfigurationLSC33MHz Mod depth

The 33MHz mod depth is now controlled by the OMC (C1:OMC-SPARE_DAC_CH_15).  The setting to give us the same modulation depth as before is 14000 (in the offset field).

  2125   Tue Oct 20 11:38:10 2009 rana, rolfUpdateAdaptive Filteringextra delay and noise in PEM -> ASS/OAF system

An email from Rolf about the delay in the 110Bs:

"...we do take the ~2msec pipeline delay into account when we send the data to DAQ. If I remember correctly, the delay is about 39 samples. On startup, the first 39 samples are 'thrown away', such that, from then on, data lines up with the correct time (just read 2msec later then Penteks)."

  2124   Tue Oct 20 10:46:18 2009 steveUpdateIOOclipping IP-ANG beam at ETMX chamber

Initial pointing beam is clearly clipping on 2" pick off mirror in  ETMX vacuum chamber.

Atm. 1  The pick off mirror is just north west of the ETMX test mass

Atm. 2 The camera is looking in from the north view port of ETMX chamber. The back side of pick off mirror is visible now with the face view of the "IP-ANG-OUT" mirror.

 

Attachment 1: PA200175.JPG
PA200175.JPG
Attachment 2: PA200177.JPG
PA200177.JPG
  2123   Tue Oct 20 02:14:29 2009 robUpdateIOOMC2 alignment bias changed

the mode cleaner was having trouble locking in a 00 mode, needing several tries.  I changed the MC2 coil biases, and it seems better for now.

  2122   Mon Oct 19 23:14:32 2009 kiwamuUpdateLSCLSC timing issue

I measured the noise spectrum of LSC_DARM_IN1 and OMC-LSC_DRIVE_EXC by using DTT,

while injecting the sin-wave into the OMC-LSC_DRIVE by AWG.

The attached are the results.

No significant differences appears between OMC and LSC in this measurement.

It means, in this measurement we can not figure out any timing noise which might be in LSC-clock.

In addition there are the noise floor, whose level does not change in each 3-figures. The level is about ~4*10^{-8} count/sqrt[Hz]

(The source of the noise floor is still under research.)

Attachment 1: SPE20Hz.png
SPE20Hz.png
Attachment 2: SPE200Hz.png
SPE200Hz.png
Attachment 3: SPE2kHz.png
SPE2kHz.png
  2121   Mon Oct 19 19:37:39 2009 Sanjit, JenneUpdateAdaptive Filteringextra delay and noise in PEM -> ASS/OAF system

Rana pointed out that the delay may be caused by the 110B DAQ, as it integrates over 2ms (5 clock cycles at 2048Hz on the fe computer), to make low noise measurement. However, the C0DCU knows about this delay and corrects it by fudging the time stamp, before sending it to the frame builder, so that the time stamps match the actual measurement time. But, the ASS computer is not aware of such an integration time, so it does not adjust the time. We verified that it is indeed the case. This is what we did (as suggested by Rana):

We split the signal from the MODE cleaner board "OUT" port using a T-splitter to the original PENTEK board (C1:SUS-MC2-MCL-IN) and the PEM ADCU channel #2. Then measured the mutual delays between the signals that are processed by C0DCU and the ASS computer for both the MC_L signal and the corresponding output through the PEM channel. We clearly see the same delay (compare red and brown in the bottom panel) between the signals that are going through 110B and the PENTEK DAQ. This delay is a bit noisy, possibly because the PENTEK is not as low noise as the 110B is.

There is some delay (pink curve in the bottom panel) between the PENTEK DAQ and the frame builder corrected 110B output, much smaller than 2ms, could be ~200-400 u sec. Which should correspond to the 1 or 1/2 cycle delay caused by the PENTEK DAQ.

So, once we have the planned advLIGO DAQ system, there should not be any long delay. Perhaps, to solve the problem and make OAF functional soon, we will upgrade the PEM DAQ asap, rather than waiting for the rest of the upgrades...

 

Attachment 1: PEM_timingDealy_19OCT09_MCL2PEM2.png
PEM_timingDealy_19OCT09_MCL2PEM2.png
  2120   Mon Oct 19 18:14:28 2009 robUpdateCamerasvideo switch broken

The Chameleon HB (by Knox) video switch that we use for routing video signals into the control room monitors is broken.  Well, either it's broken, or something is wrong with the mv162 EPICS IOC which communicates with it via RS-232.  Multiple reboots/resets of both machines has not yet worked.  The CHHB has two RS-232 inputs--I switched to the second one, and there is now one signal coming through to a monitor but no switching yet. I've been unable to further debug it because we don't have anything in the lab (other than the omega iserver formerly used for the RGA logger) which can communicate with RS-232 ports.  I've been trying to get this thing (the iserver) working again, but can't communicate with it yet.  For now I'm just going to bypass the video switch entirely and use up all the BNC barrel connectors in the lab, so we can at least have the useful video displays back.

  2119   Mon Oct 19 17:12:54 2009 jenneUpdatePEMaccelerometers and seismomters are all good.

Quote:

Some of these channels are not like the others.

 All of the PEM channels seem to be okay right now.  The accelerometers didn't turn out to have any differences in the traces when we put both XYZ triplets right next to each other, so we put them back where they belong.  Gur2 seismometer was showing a few problems, especially with Gur2_X, as Rana posted in elog 2079.  This was solved by tightening the cable screws which hold the Dsub end of the Guralp cable to the front panel of the Guralp box.  All is now well.

Attachment 1: SeismometersGoodSpectra_19Oct2009.png
SeismometersGoodSpectra_19Oct2009.png
  2118   Mon Oct 19 14:48:15 2009 rana, robSummaryElectronicspiezo jena measuring box
Attached is the schematic of the Piezo Jena driver measuring box made in a Pomona box:
                2.2 uF
In ----o-------- | | --------o-------- Out
       |                     |
       _                     |
       _  1uF                R  7.5 kOhms
       |                     |
       |                     |
      GND                   GND
The 1 uF cap is there to simulate the piezo and the 2.2 uF and 7.5k resistor ac couple the signal for the spectrum analyzer. They give a ~10 Hz corner frequency.
Attachment 1: PA160153.JPG
PA160153.JPG
Attachment 2: PA160151.JPG
PA160151.JPG
  2117   Mon Oct 19 13:00:53 2009 MottUpdateGeneralPhase Noise Measurement

Here is the result for the measurement of the phase noise.  We used the marconi function generator and compared it with an Isomet AOM driver (model 232A-1), so this is really a measure of the relative phase between them.  We used a 5x gain and a frequency response of 13 Hz/V for the modulation.  In all the attached plots, the blue is the data and the red is the measurement limit (as determined by the noise in the SRS785).  Also note that the units on the yaxis of the Phase noise plot are incorrect, they should be dB/Sqrt(Hz), I will fix this and edit as soon as possible.

Attachment 1: PhaseNoiseWithError.jpg
PhaseNoiseWithError.jpg
Attachment 2: G.jpg
G.jpg
Attachment 3: PSD.jpg
PSD.jpg
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