40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 283 of 339  Not logged in ELOG logo
ID Date Authorup Type Category Subject
  3525   Mon Sep 6 01:46:58 2010 ranaUpdatePSLPSL update of the day

To bypass the polarizer issue, I just used cubes. One I took from the FSS-Refcav path and the other from the power control part of the old MOPA, just downstream of the MOPA's periscope.

We'll swab these out with the thin-film polarizers after we get the mounts made.

With the cubes in, I also installed the Faraday + its 1/2-wave plate. The transmission looks good and we're getting into the PMC and its flashing a TEM00 mode sometimes. I set up a signal generator to drive the SLOW actuator by 1 FSR at 0.1 Hz.

I have set up a PMC transmission camera and transPD so that its easy to align. The flashing mode already allows us to align most of the rest of the table (except FSS).

Our next step should be to run the cables for locking the PMC:

  1. RF cables to the PMC_REFL
  2. Dsub for the PMC RFPD
  3. HV cable between the PMC servo board and the PMC PZT (why is this not RED? we have to make sure to abide by the cabling color code).
  4. RF cable from 35.5 MHz Frequency Reference card to the PMC EOM via the RF summing box on the table.

On Tuesday, we need to make sure that all of our mounts' drawings are in the cue for the shop. I'll put the list of mounts onto the PSL upgrade wiki page.

We also have to come up with a plan for wiring some of the 2W NPRO's channels into the cross-connect so that we can have some laser channels recorded by EPICS.

  3528   Mon Sep 6 21:08:44 2010 ranaUpdateCDSSusension model reviewed

We must remember that we are using the Rev.B SOS Coil Drivers and not the Rev. A. 

The main change from A->B was the addition of the extra path for the bias inputs. These inputs were previously handled by the slow EPICS system and not a part of the front end. So we used to have a separate bias screen for these than the bias which is in the front end. The slow bias is what was used for the alignment to avoid overloading the range of the main coil driver path.

  3543   Wed Sep 8 09:50:13 2010 ranaUpdatePSLPSL update

Also, Kiwamu has modified the layout drawing to add the green PLL stuff. This has collapsed the reference cavity's wave function placing it close to its original position.

WE (maybe Valera and Steve) can now put the reference cavity back on the table.

  3554   Thu Sep 9 16:54:56 2010 ranaUpdateSAFETYmain laser is back ON

I turned off the laser last night to protect against the electricians. but failed to elog it. I accept the burnt toast completely.

  3557   Sat Sep 11 03:16:51 2010 ranaConfigurationComputersrossa notes

I wiped out the old CentOS install on rossa and installed CentOS 5.5 on there. The DVDs are on a spindle in the control room; there were 2 iso's, but I only needed the first to install most things.

It still needs to get all of the usual stuff (java, flash, nvidia) installed as well as setting up the .cshrc and the NFS mount of /cvs/cds. The userID and groupID are set to 1001 as before. Whoever

sees Sanjit first should steer him towards this elog entry.


  3559   Sun Sep 12 22:36:03 2010 ranaConfigurationComputersrossa notes

I found Sanjit's instructions for doing the Nvidia settings too complicated and so I followed these instructions from Facebook:


After installations, the monitors were autodetected and the Xinerama effect is working.

  3562   Mon Sep 13 00:19:32 2010 ranaUpdate VCO Driver Output power v. slider control voltage

I measured the RF power output of the VCO Driver box as a function of slider value. I measured using the Gigatronics Handheld power meter and connected to the AOM side of the cable after the white Pasternak DC block.

* at low power levels, I believe the waveform is too crappy to get an accurate reading - that's probably why it looks non-monotonic.

* the meter has a sticker label on it saying 'max +20 dBm'. I went above +20 dBm, but I wonder if maybe the thing isn't linear up there...

Attachment 1: vco.png
  3563   Mon Sep 13 02:45:59 2010 ranaConfigurationDMFseisBLRMS restarts

I restarted the seisBLRMS DMF monitor by ssh'ing into mafalda and starting up a matlab session. I also have started a StripTool session on rossa by forwarding the process from op440m.

We need to get the modern EPICS installation onto these linux machines by copying what K. Thorne has done at LLO.

  3568   Mon Sep 13 19:41:38 2010 ranaUpdatePSLFSS AOM alignment

The IR sensitive Olympus 570 camera gives us a really nice view of these IR beams. Its actually a lot better than what you can get with the analog IR viewers:


  3571   Tue Sep 14 00:21:51 2010 ranaOmnistructureEnvironmentOffice area temperature change

I changed the setpoint for the HVAC control (next to Steve) from 73F to 72F. This is to handle the temperature increase in the control room with the AC unit there turned off.

We know that the control setpoint is not linear, but I hope that it settles down after several hours. Lets wait until Tuesday evening before making another change.

  3586   Sun Sep 19 18:09:09 2010 ranaConfigurationCamerasBlue IP Camera installed on the PSL table


I installed the blue IP camera from ZoneNet onto the PSL table. It gets its power from the overhead socket and connects via Cat5 to the Netgear switch in the PSL/IO rack.

You can connect to it on the Martian network by connecting to Your computer must have Java working in the browser to make that work.

So far, this works on rossa, but not the other machines. It will take someone with Joe/Kiwamu level linux savvy to fix the java on there. I also don't know how to fix the host tables, so someone please add this camera to the list and give it a name.

As you can see from the image, it is  illuminating the PSL with IR LEDs. I've sent an email to the tech support to find out if we can disable the LEDs.

  3587   Sun Sep 19 18:52:52 2010 ranaConfigurationPSLNPRO SLOW servo settings updated for Innolight NPRO

Our new 2W Mephisto has a pretty zippy "SLOW" temperature input. Tuning the perl PID servo, I found that the best response came from setting

the "P" and "D" terms to zero. This is because the internal temperature stabilization servo has a fairly high UGF. In the attached

image you can see how the open loop step response looks (loop is open then the "KI" parameter is set to zero). The internal servo

really has too little damping. There is a 30% overshoot when it gets a temperature step. For this kind of servo Innolight would have done better

to back off on the gain until they got back some phase margin.

New SLOW parameters:

timestep = 1.9 s

KP = 0

KI = 0.035

KD = 0

Attachment 1: Untitled.png
  3598   Thu Sep 23 10:34:20 2010 ranaFrogsComputersnodus gracefully rebooted

SVN down

mafalda down

I am guessing that the NFS file system hangup may have caused some machines to get into an awkward state. We may be best off doing a controlled power cycle of everything...

  3610   Mon Sep 27 00:33:50 2010 ranaUpdatePSLHigh Voltage Driver added to TTFSS -> NPRO

We added the Thorlabs HV Driver in between the FSS and the NPRO today. The FSS is locking with it, but we haven't taken any loop gain measurements.

This box takes 0-10 V and puts out 0-150 V. I set up the FSS SLOW loop so that it now servos the output of FAST ot be at +5V instead of 0V. This is an OK

temporary solution. In the future, we should add an offset into the output of the FSS board so that the natural output is 0-10 V.

I am suspicious that the Thorlabs box has not got enough zip to give us a nice crossover and so we should make sure to measure its frequency response with a capacitive load.

  3618   Wed Sep 29 01:53:44 2010 ranaUpdatePSLpaths broken and VCO turned off

I found that several linux libraries have been moved around and disabled today. In particular, I see a bunch of new stuff in apps/linux/ and ezca tools are not working.

Who did this and why is there no ELOG ???


Also found that someone has pulled the power cable to the function generator I was using to set the VCO offset. This is the one on top of the Rb clocks. Why?? Why no elog? This is again a big waste of time.

  3631   Thu Sep 30 21:55:31 2010 ranaUpdateCDSDAQ sys update

Its pretty exciting to see that Joe got Alex to actually use the ELOG. Its a proof that even rare events occur if you are patient enough.

1) I fixed the MEDM links to point to the new sitemap.adl in /opt/rtcds. There is a link on the new sitemap which points to the old sitemap so that there is nothing destroyed yet.

2) Some of the fields in the screen are white. These are from the new c1sus processor, not issues with the slow controls. I think its just stuff that has not yet been created in the C1SUS simulink module.


3) The PZT steering controls are gone. Without this we cannot get the beam down the arm. Must fix before aliging things after the MC. Since PZT used to be controlled by ASC, we'll have to wire the Piezo Jena PZT controls in from a different VME 4116. Possibly c1iool0's crate?

4) Also, the IPANG and IPPOS are somehow not working right. I guess this is because they are part of the ASC / the old ETMX system. We'll have to wire the IPANG QPD into the new ETMY ADC system if we want to get the initial alignment into the Y-arm correct.

5) I've started migrating things over from the old SITEMAP. Please just use the new SITEMAP. it has a red link to the old one, but eventually everything on the new one will work after Joe, Alex, me, and Kiwamu are done tweaking.


  3649   Tue Oct 5 13:52:15 2010 ranaUpdateCDSproof of trend


  3657   Wed Oct 6 00:32:01 2010 ranaSummaryDAQNDS2

This is the link to the NDS2 webpage:


We should install this so that we can use this modern interface to get 40m data from outside and inside of the 40m.

  3660   Wed Oct 6 14:49:54 2010 ranaSummaryloreSteve on the sea


  3691   Mon Oct 11 20:52:00 2010 ranaUpdateCDSActivation of DAQ channels for 8 optics

Bah!  We tried to get some data but totally failed. It seems like there is some rudimentary functionality in the FE process of the MC, but no useful DAQ at all.

Neither Dataview or DTT had anything. We looked and the NDS process and the DAQD process were not running on FB.

I restarted them both (./daqd -c daqdrc) & (./nds pipe > nds.log) but couldn't get anything.

There's a bunch of errors in the daqd.log like this:

    Warning: "Identical process variable names on multiple servers"
    Context: "Channel: "C1:SUS-MC1_SUSPOS_INMON", Connecting to: c1susdaq:57416, Ignored: c1sus.martian:57416"
    Source File: ../cac.cpp line 1208
    Current Time: Mon Oct 11 2010 18:25:15.475629328
    Warning: "Identical process variable names on multiple servers"
    Context: "Channel: "C1:SUS-MC1_SUSPIT_INMON", Connecting to: c1susdaq:57416, Ignored: c1sus.martian:57416"
    Source File: ../cac.cpp line 1208
    Current Time: Mon Oct 11 2010 18:25:15.475900124

  3702   Tue Oct 12 23:45:55 2010 ranaConfigurationDAQNDS2

I installed the NDS2 Client onto the workstations today using the instructions that Zach put onto the Wiki with a couple of modifications.

1) Instead of the adding path stuff in Matlab, I added the LD_LIBRARY_PATH and MATLABPATH variables into the .cshrc as instructed by JZ's NDS2 Wiki.

2) I installed the stuff into the shared /cvs/cds/caltech/apps/linux64/ partition so that it works now on all the 64-bit CentOS 5.5 workstations.

To run it you do:

> kinit albert.einstein

> matlab -nodesktop -nosplash

> help NDS2_GetData

(set the server to the NDS2 server that you like - the example in the help is fine)

> result = NDS2_GetData({'L1:LSC-DARM_ERR'}, 957313530, 10, server);

> plot(result.data)

Now you can get any of the S6 data super fast.

(** Remember to run kdestroy as soon as you are finished so that no one else in the control room can use your personal credentials. **)

Attachment 1: cerberus.jpg
  3704   Wed Oct 13 09:35:41 2010 ranaUpdateelogstart script edited

The existing elog restart script was running the kill process in the background using the '&' symbol before starting new elog process. This is a BAD idea since there's no way to make sure that the background process has actually worked before the new one tries to start.

That's why you sometimes had to run the script twice. I've removed all of the background "cleverness" so now it will take ~2s more for the script to run - however, it now actually works. We may also upgrade from v2.7.5 to 2.8 today.

  3712   Thu Oct 14 00:54:12 2010 ranaHowToCDSBad PSL Quad, so I edited the SUS MEDM screens

We found today that there was some (unforgivably un-elogged) PSL-POS & PSL-ANG work today.

The wedge splitter at the end of the PSL table is so terribly dogged that it actually moves around irreversibly if you touch the post a little. Pictures have been recorded for the hall of shame. This should be replaced with a non-pedestal / fork mount.

I was so sad about the fork clamp, that I edited the SUS Master screen instead according to Joe-Yuta instructions; see attached.Untitled.png

There's clearly several broken/white links on there, but I guess that Yuta is going to find out how to fix these from Joe in the morning.

  3732   Mon Oct 18 08:44:36 2010 ranaUpdateCDSslow DAQ channels added

Why EXCMON? I think that we should modify the filter coefficients so that the decimation filter that makes OUT16 is a 2nd order Butterworth at 1 Hz instead of whatever bogus thing it is now. Then we can delete the EXCMON from the DAQ and add either OUTPUT or OUTMON. That way we will have a low frequency signal (OUT16) and a sort of aliased RMS (OUTMON).

  3749   Thu Oct 21 01:11:48 2010 ranaSummaryComputerselog change and rossa tex

I deleted a bunch of categories from the elogd.cfg file. Not every kind of locking and activity gets its own activity. All of the things related to length sensing and control should be LSC. If there's a high pollen count its under PEM. etc., etc., etc.

I decided that the 'tetex' distribution which comes with CentOS is total BS and I removed it from rossa using 'yum erase tetex'. I installed TexLive using the instructions on the web; its much better, actually works, and also has RevTex 4.1 which allows Jenne and I to write our paper.

Eventually, we'll standardize our workstation setups.

Yuta has also successfully set up zita to run the projector, so we should clear our some of the boxes and bookshelves in that area so that the projection can be larger.

  3752   Thu Oct 21 12:15:02 2010 ranaUpdatePEM6.9 Mag EQ in Gulf of California
Magnitude 6.9
Location 24.843°N, 109.171°W
Depth 10 km (6.2 miles) set by location program
Distances 105 km (65 miles) S of Los Mochis, Sinaloa, Mexico
125 km (75 miles) SW of Guamuchil, Sinaloa, Mexico
140 km (85 miles) NE of La Paz, Baja California Sur, Mexico
1200 km (740 miles) WNW of MEXICO CITY, D.F., Mexico
Location Uncertainty horizontal +/- 6.1 km (3.8 miles); depth fixed by location program
Parameters NST=187, Nph=187, Dmin=843.1 km, Rmss=1.17 sec, Gp=133°,
M-type=teleseismic moment magnitude (Mw), Version=6
Event ID us2010crbl
  3772   Sun Oct 24 19:23:41 2010 ranaConfigurationelogELOG 2.8.0
I stopped the ELOG and restarted us on 2.8.0.

To make sure nothing got lost, I killed the old process, copied over the logbooks/, themes/, and elogd.cfg to the new 2.8.0/ directory before starting the new Daemon.

I encountered the same Administrator bug as Joe had before. I delete all the old Admin passwords to bypass the issue.

To restart the ELOGD on NODUS, you now type '/cvs/cds/caltech/elog/start-elog.csh'.
I also added ELOG to the man pages in /usr/local/man/ on nodus by putting the *.1 files in man1/ and the *.8 files into man8/.
  3781   Tue Oct 26 00:45:08 2010 ranaUpdatePSLNew NPRO Diagnostic Wiring


I copy section 6.2 into here to share with you all what the diagnostic capabilities of the new NPRO are. Its not a lot.

We'll need to record a sample of the NPRO output beam on a regular photodiode in order to get a real power monitor. My plan is to use a regular 25-pin Dsub and run it fron the NPRO controller over to the PSL rack and hijack the old MOPA monitoring channels (3113 and 3123 ADCs).

  3806   Thu Oct 28 04:23:38 2010 ranaUpdateIOOA2L prep

To get the angle to length signal before the c1ioo processor gets going, we need a length signal. We can use either the error signal or the control signal.

I recommend using the control signal since its not puny. The 4-pin LEMO inputs to the OSEM ADC that Suresh has wired are differential so we can, in principle, use either the BNC output of the SERVO plug or the 2-pin LEMO output.

The analog whitening on the OSEM Whitening board should be engaged via the SUS MEDM screen so that we get a good SNR at the A2L dither frequencies.

If the ADC saturates, then we should use a pomona box RC low pass to cut everything off above 100 Hz.

Also, a comment about Yuta's elog: we estimated that the seismic motion was ~1e-7 - 1e-6 meters. The MC linewidth ought to be ~lambda/(2*Finesse) ~ 1e-9.

So, the MC servo as it was was not giving us enough gain (1/f above 50 Hz; UGF ~5-10 kHz) to get the error signal to stay in the linear PDH region. Kevin's filter gave us ~10x more gain at the seismic frequencies (1-3 Hz) of concern.

  3831   Sun Oct 31 00:19:35 2010 ranaSummaryComputer Scripts / ProgramsHP3563A netGPIB function

I've wheeled the old HP audio frequency signal analyzer into the control room to debug the GPIB/python interface. The wireless setup was getting more than 80% packet loss in the office area.

I also noticed that we have multiple and competing copies of the netgpib package installed. Kiwamu is going to merge them soon. Pleae only use the official location:


which is also the SVN working copy. Committ all changes periodicallty so that we can share the updated versions between sites.

  3852   Wed Nov 3 09:32:00 2010 ranaSummaryCDSEurocard board swapping

When swapping Eurocard boards, it is safest to first turn down the power supplies and then do the swapping.

Otherwise, it is sometimes the case that people plug in the board slowly and/or asymmetrically. This can cause the opamp to see one of the power supply rails without the other (e.g. +15 but not -15).

This can destroy some opamps. The true danger is that there may be damage to the board which you do not notice for several months, thereby leaving a timebomb for the next person.

Don't be an electronics terrorist!

  3856   Wed Nov 3 19:14:00 2010 ranaUpdatePSLPMC mode matching update

I moved the lens just before the PMC to check the mode matching landscape. The PMC trans went up from ~6.5 to ~6.8. That's 5% with ~1 hour of work.

As per the micrometer, this took ~7-8 mm of travel. Since there's so much power left in the HOMs, we we we will have to do a proper mode scan and re-calculate the solution.

The measured transmission is now ~610 mW. The power reflected from the PMC with it unlocked is ~1400 mW.

  3858   Wed Nov 3 23:58:45 2010 ranaUpdateElectronicsCougars

I looked at this web page: http://www.teledyne-cougar.com/Index.asp for the RF company that Rich has recently started using.

There are ~15 amplifiers that they sell which have a NF < 2 dB and work in the 10-100 MHz band. We should call them to find out if they will package some amps for us or at least sell us a few with eval. boards so that we can make our own.

  3872   Fri Nov 5 21:49:12 2010 ranaSummaryCDS40m computer slow down solved



The 40m computers were responding sluggishly yesterday, to the point of being unusable.


The mx_stream code running on c1iscex (the X end suspension control computer) went crazy for some reason.  It was constantly writing to a log file in /cvs/cds/rtcds/caltech/c1/target/fb/  In the past 24 hours this file had grown to approximatel

The moral of the story is, PUT THINGS IN THE ELOG. This wild process is one of those things where people say 'this won't effect anything', but in fact it wastes several hours of time.

  3873   Fri Nov 5 23:05:43 2010 ranaConfigurationIOOioo.db file changed in c1iool0 to get back MC TRANS


We like to have the MC TRANS channels so that we can run all of our old scripts and trends on it. This is the usual BROWN

channel that's on the LockMC screen. Its also the thing that we use for thresholding to activate the MC Autolocker Daemon.

I modified the ioo.db file in the target/c1iool0/ directory so that the MC_TRANS_SUM, _P, and _Y channels are all now just

CALC records of the MC2 OL channels (where the calculation is MC_TRANS_SUM = MC2 OL_SUM + 0.001, etc.). I then

rebooted c1iool0 a few times to get the syntax right. It SEEMS to be working now. I'm sure that this won't effect anything.
I've committed the new file to the SVN repo. Once Suresh is done hacking the QPD circuit, we can set the threshold in the Autolocker.

  3877   Sat Nov 6 16:13:14 2010 ranaSummaryCDS40m computer slow down solved

As part of the effort to debug what was happening with the slow computers, I disabled the auto MEDM snapshots process that Yoichi/Kakeru setup some long time ago:


We have to re-activate it now that the MEDM screen locations have been changed. To do this, we have to modify the crontab on nodus and also the scripts that the cron is calling. I would prefer to run this cron on some linux machine since nodus starts to crawl whenever we run ImageMagick stuff.

Also, we should remember to start moving the old target/ directories into the new area. All of the slow VME controls are still not in opt/rtcds/.

  3914   Sun Nov 14 02:59:31 2010 ranaConfigurationGeneralMEDM snapshots web page

Since Nodus is a Solaris machine it can barely handle doing the ImageMagick commands (such as convert and import). I removed the auto MEDM snapshot routine from it

awhile ago and I think the rate of ELOGD crashes has decreased, although its not definitive.

The snapshots have now been re-actived to run on MAFALDA, after I fixed the absolute pathnames in the scripts and installed (via yum) the packages that mafalda

needed to run this (Xvfb, openmotif, compat, etc.). The snapshots web page is now refreshing by itself and the statScreen/cronjob.sh is running on mafalda 5x per hour.


  3918   Mon Nov 15 04:57:10 2010 ranaUpdateElectronicsSRM side OSEM noise with no magnet

IF I believe this calibration and IF I believe that the noise is the same with no magnet in there, then its almost 1 nm/rHz @ 1 Hz.

I am guessing that Jenne's calculation will show that this is an unacceptably high level of OSEM sensor noise, OAF-wise.

  3935   Tue Nov 16 21:42:31 2010 ranaUpdateCDSScreen Time Fix
I learned today that the following python code will do a find/replace to fix the TIME string on any MEDM screen which has a whited out time field.
Previously, this field was sourced from the c1dscepics of c1losepics process. Now we have to get it from the IOO or SUS front ends

Here's the python code:

import re
o = open("output.adl","w")
data = open("test.adl").read()
o.write( re.sub("C0:TIM-PACIFIC_STRING","C1:FEC-34_TIME_STRING",data)  )

Where 'output.adl' could be the same name as 'test.adl' if you want to
replace the existing file. Also FEC-34 just refers to which FE you're running.
It could, in principle, be any one of them.

The next step is to figure out how to apply this to all the files in a directory.

  3939   Wed Nov 17 15:49:53 2010 ranaUpdateDAQOle Channel Names

The following channels should be named as below to keep in line with their names pre-upgrade rather than use _DAQ in the name.






  3951   Thu Nov 18 23:45:18 2010 ranaConfigurationPSLPMC Refl Cam

Valera and Haixing and I installed a PMC REFL camera today. We stole the camera control box from the MC2 trans area (because I don't know why we need a camera there).

We installed it such that it is looking at the leak through of the last turning mirror before the PMC REFL RFPD. This beam was previously going into a Thorlabs razor blade dump.

There is no steering mirror to align into this camera; we just positioned the camera such that the REFL beam fills up the monitor. WE cable tied the cable to the table and the

output of the camera control box is piped into the control room correctly as PMCR. The "IMCR" quadrant is actually the PMCT beam. JoonHo is going to fix this promptly.

Also, I noticed how beautiful  the MC2 Simulink diagram is so I post it here for your viewing pleasure. We should take this as a reference and not produce any new diagrams which are less useful or beautiful or easy to understand.

Attachment 1: mc2_simulink.png
  3983   Tue Nov 23 23:52:49 2010 ranaUpdateCDSUpdated apps

Wow. I typed DTT on rossa and it actually worked! No complaints about testpoints, etc. I was also able to use its new 'NDS2' function to get data off of the CIT cluster (L1:DARM_ERR from February). You have to use the kinit/kdestroy stuff to use NDS2 as usual (look up NDS2 in DASWG if you don't know what I mean).

  4005   Thu Dec 2 00:34:32 2010 ranaHowToLSCHow Does Cavity Locking Work (answered by Nikon)


Dr. Koji Arai and Nikon
  4008   Fri Dec 3 14:34:23 2010 ranaUpdateCDSfooling around in the FB rack

This morning (~0100) I started to redo some of the wiring in the rack with the FB in it. This was in an effort to activate the new Megatron (Sun Fire 4600) which we got from Rolf.

Its sitting right above the Frame Builder (FB). The fibers in there are a rats nest. Someone needs to team up with Joe to neaten up the cabling in that rack - its a mini-disaster.

While fooling around in there I most probably disturbed something, leading to the FB troubles today.

  4011   Sun Dec 5 22:28:39 2010 ranaSummaryall down cond.power outage

Looks like there was a power outage. The control room workstations were all off (except for op440m). Rosalba and the projector's computer came back, but rossa and allegra are not lighting up their monitors.

linux1 and nodus and fb all appear to be on and answering their pings.

I'm going to leave it like this for the morning crew. If it

  4051   Tue Dec 14 04:14:53 2010 ranaUpdateElectronicsRF Photodiode Characterizations

This is looking better, but the fit data for the TF should be plotted along with the data. The data should be made up of points and the fit a line.

For the fit, we should have the Q of the main resonance as well as the peak height of the main resonance and the values of the gain at the notch frequencies.

Also the peak as well as the notches should have the frequencies fit for and labeled. In principle, you can make the plot on the wiki have all of the data. Then in the end we can print the plot in a small size and glue it to the PD's backside.

  4069   Fri Dec 17 03:37:47 2010 ranaUpdateSUSITMY / SRM / BS / PRM OPLEVs aligned


The sole thing that has been deviated from the optical layout was that the SRM returning beam had to be reroute
as the SRM has better reflectivity on the AR surface in stead of the HR one.

 I suppose that if we were really clever we would intentionally choose either the AR or HR surface so as to minimize the effect of the thermal lensing and/or thermal expansion from the locked interferometer absorption.

  4071   Sat Dec 18 06:24:49 2010 ranaUpdateelogrestarted

The process was taking up 100% of the CPU and not responding via web. The .log file showed the last action was somebody reading/editing one of Jenne's entries from August regarding TT ECD. The restart script didn't work, so I had to do a 'kill -9' to get it to die.

  4074   Sun Dec 19 22:45:28 2010 ranaUpdateelogrestarted

I deleted the yellow box which showed up by default when making an elog entry. Would be nice if we could make it so that you have to click a button to 'opt-in' for the yellow box rather than get it by default.

I added a 'robots.txt' file to the /users/public_html/ area using Google's instructions (it only works with robot compliant crawlers), but am not sure how to put robots.txt into the elog port.

  4081   Tue Dec 21 08:26:08 2010 ranaUpdateelogelogd is getting killed by Suresh

Suresh killed the elogd again from India. This was the log file:

Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Referer: http://www.ligo.caltech.edu/~ajw/40m_upgrade.html
Cookie: elmode=threaded; __utma=65601905.411937803.1291369887.1291369887.1291369887.1; __utmz=65601905.1291369887.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); SITESERVER=ID=4981c5fd42ae53c9c9e0980f2072be4f
Via: 1.1 sfire5.du.ac.in:3128 (squid/2.6.STABLE6)
Cache-Control: max-age=259200
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Stop killing our elog!

ELOG V3.1.3-