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ID Date Author Type Categorydown Subject
  16068   Wed Apr 21 19:28:03 2021 AnchalUpdatePSLPSL/IFO recovery

[Anchal, Koji]

Removed the top sheet

  • Opened first from the door side so that any dust would spill outside.
  • Then rolled the sheet inward to meet in the middle.
  • Repeated this twice for the 2 HEPA filters.

Removed the sheets on the table

  • Lifted sheet up making sure the top side face outside always.
  • Rolled it sideways halfway through.
  • Cut down the sheet vertically.
  • Slided the doors to the other side and rolled the remaining half.
  • On the door side, the sheets above the ALS optics were simply lifted off.

Restarting PSL

  • Turned on the HEPAs at the max speed
  • Switched on laser to jsut above the threshold
    • Before the 1st eom, power was 20mW 
    • After the EOM/AOM, 18mW. So about 90% transmission through all polarizing optics.
    • We saw the resonances of the PMC but could not lock it even with highest gain available (30 dB).
  • Increased the input power to PMC to 100mW
    • Locked the PMC at 30dB gain
    • The transmitted power was ~50-60 mW. (Had to use power meter suspended by hand only.
    • The right before the IMC (after the 2nd EOM) 48mW. So none of the alignment was lost.
  • Opened the PSL shutter.
  • We were able to see IMC reflection signal.
  • We were also able to see IMC catching lock as the servo was left ON earlier.
  • Switched off the servo.
  • Decided to increase the power while watching PMC Trans/Refl and IMC REFL
  • Injection diode current to innolight was increased slowly to 2.10A. Saw a mod hopping region aroun 1.8A.
  • We recovered the PMC Trans >0.7 V.
  • PZT was near the edge, so moved by one FSR.
  • The PMC refelction signal is still shown in red at around 48 mV.

Back to control room

  • IMC was locked almost immediately by manually finding the lock while keeping IMC WFS off to preserve the offsets from yesterday.
  • Then switch on IMC WFS. Working good.
  • Then unlocked the servo and switched on IMC Autolocker. Lock was caught immediately.

Decided to start locking the arms

  • The arm transmissions were flashing but at 0.2~0.3 level.
  • Decided to adjust TT1 and TT2 Pitch and Yaw to align the light going into the arms.
  • This made TRY ~0.6 / TRX ~0.8 at the peak of the flashing
  • Locked the arms. (By switching on C1:LSC-MODE_SELECT which engages all servos).
  • Used ASS to align Yarm then align Xarm. Procedure:
    • Sitemap > ASC > c1ass
    • Open striptool to look at progress. ! Scripts YARM > striptool.
    • Switch on ASS. ! More Scripts > ON
    • Wait for the TRY to reach to around 0.97.
    • Freeze the outputs. ! Scripts > Freeze Outputs.
    • Offload the offsets to preserve the output. ! More Scripts > OFFLOAD OFFSETS.
    • Switch off ASS. ! More Scripts > OFF
    • Repeted this for XARM.
  • At the end, both XARM and YARM were locked with TRX ~ 0.97 and TRY ~ 0.96.
  16069   Wed Apr 21 19:43:20 2021 KojiUpdatePSLNew HEPA speed control

The new HEPA speed controllers are attached at the middle of the HEPA unit (not at the edge of the unit)... (Attachment 1)
You still need a step./stool to touch the knob and need a ladder for a more precise setting.

We still don't know the optimal speed of the nominal IFO operation. For now, the HEPAs are running at the max speed (Attachment 2).
Once we know the optimal setting, we mark the knobs so that we can see them only with the step.

Attachment 1: P_20210421_193637.jpg
P_20210421_193637.jpg
Attachment 2: P_20210421_193627.jpg
P_20210421_193627.jpg
  16074   Thu Apr 22 14:41:55 2021 ChubUpdatePSLNew HEPA speed control

When adjusting the blower speed, give the blower at least 30 seconds to speed up or slow down to the set speed.  The flywheel effect of the big motor armature and blower mass requires time to follow the control current.  Note the taller Flanders HEPA filters.  These and the new intake filters should keep the PSL air clean for a long time!

Quote:

The new HEPA speed controllers are attached at the middle of the HEPA unit (not at the edge of the unit)... (Attachment 1)
You still need a step./stool to touch the knob and need a ladder for a more precise setting.

We still don't know the optimal speed of the nominal IFO operation. For now, the HEPAs are running at the max speed (Attachment 2).
Once we know the optimal setting, we mark the knobs so that we can see them only with the step.

 

Attachment 1: 40M_PSL_HEPA.jpg
40M_PSL_HEPA.jpg
  16076   Thu Apr 22 15:15:26 2021 gautamUpdatePSLPMC transmission

I was a bit surprised by these numbers suggesting the PMC transmission is only 50-60%. I went to the table today and confirmed that it is more like 85% (1.3 W in, 1.1 W transmitted, both numbers from with the FieldMate power meter), as I claimed in 2019. Even being conservative with the power meter errors, I think we can be confident T_PMC will be >80% (modulo any thermal effects with higher power degrading the MM). There isn't any reliable record of what the specs of the PMC mirrors are, but assuming the IO couplers have T=4000ppm and the end mirror has T=500ppm as per Alan's plot, this is consistent with a loss of something like 300ppm loss per mirror - seems very high given the small beam spots, but maybe these mirrors just aren't as high quality as the test masses?

It's kind of unfortunate that we will lose ~20% of the amplifier output through the first filter, but I don't see an easy way to clean these mirrors. It's also not clear to me if there is anything to be gained by attempting a cleaning - isn't the inside of the cavity supposed to be completely isolated from the outside? Maybe some epoxy vaporization events degraded the loss?

Quote:

The transmitted power was ~50-60 mW. (Had to use power meter suspended by hand only.

  16077   Thu Apr 22 15:34:54 2021 AnchalUpdatePSLPMC transmission

Koji mentioned that the mode of the laser is different for lower diode currents. So that might be the reason why we got less transmission at the low input power but more afterward.

  16080   Thu Apr 22 17:28:34 2021 YehonathanUpdatePSLLaser amplifier

According to the aLIGO 70W amplifier interlock concept the flow rate of the chiller should be between 5 and 40 l/min. The chillers I found in the TCS lab both have around 15 l/min flow rate so we should be fine in that regard.

Assuming that the power consumption of the diode box is ~800W and that the optical output power of the diode is ~ 300W of optical power, the chillers need to be able to remove the remaining power. At room temperature, they both have enough cooling capacity according to their specs.

As for the idea to put the chiller and diode box in the drill room: There are not a lot of options here. The only viable place is the SW corner (attachment 1). I was told this place is used sometimes for liquid nitrogen dewar. Alternatively, if possible, we can move the fire extinguishers to the SW corner and use the NW corner. In that way, we don't have to clear all the junk from the SW corner, as long as the extinguishers are still accessible.

I made a sketch (attachment 2) showing a possible setup for a diode box + chiller rack. The fiber and network cable can go through the hole in the wall that already exists for the N2. It will have to get bigger though (attachment 3). The rack would also need to host some Acromag unit to convert the communication channel of the chiller/flow meter to Ethernet. The Acromag on 1X7 has no spare channels.

The only power socket in the room, to which the drill is connected, is circuit #36 which is connected to panel L in the lab. The breaker's ampacity seems to be 20A if I'm reading the number on the breaker correctly.

 

Attachment 1: 20210422_124940.jpg
20210422_124940.jpg
Attachment 2: DrillRoomSchematics.pdf
DrillRoomSchematics.pdf
Attachment 3: 20210422_125240_1.png
20210422_125240_1.png
  16082   Fri Apr 23 18:00:02 2021 gautamUpdatePSLHEPA speed lowered

I will upload some plots later - but in summary, I set the HEPA speed to ~40%. I used (i)IMC transmission RIN, (ii) Arm cavity transmission RIN and (iii) ALS beat noise as 3 diagnostics, to see how noise in various frequency bands for these signals change as a function of the HEPA speed. The MC2T RIN shows elevated noise between 1-10Hz at even the lowest speed I tried, ~20% of the max on each blower. The elevated noise extended to ~50-70 Hz for HEPA speeds >40% of the maximum, and the arm cavity RIN and ALS signals also start to become noisy for speeds >60% of the maximum. So I think 40% is a fine speed to run at - for squeezing measurement we may have to turn off the HEPA for 10mins but for the usual single arm / PRMI / DRMI locking, this should be just fine. For the elevated ALS noise - I'm not sure if the coupling is happening over the top of the enclosure where the fiber bringing light from EX comes close to the HEPA filters, or if it is happening inside the PSL enclosure itself, near the beat mouth - but anyways, at the 40% speed, I don't see any effect on the ALS noise.

I checked with a particle counter at the SW corner of the PSL table (which is the furthest away we can be on the table from the HEPA blowers) after leaving the blowers on for ~30mins and it registered 0 for both 0.3um and 0.5um sized particles (if the blowers are off, the respective numbers are 43 and 9 but I forgot what the units were, and I believe they have to be multiplied by 10). 

I have not yet marked the speed control units yet in case there is some other HEPA science that needs to be done before deciding what is the correct setting. But I think I can get the PRFPMI lock without much issue with this lower speed, which is what I will try later today evening.

Attachment 1: HEPAdiag.pdf
HEPAdiag.pdf
  16083   Fri Apr 23 19:26:58 2021 KojiUpdatePSLHEPA speed lowered

I believe that there is an internal setting for the minimum flow, so the flow is not linear ("0%" is not zero), but we should mark this flow speed once you find this is sufficiently low for the locking too.

  16141   Fri May 14 17:45:05 2021 ranaUpdatePSLHEPA speed raised

The PSL was too hot, so I turned on the south HEPA on the PSL. The north one was on and the south one was off (or so slow as to be inaudible and no vibration, unlike the north one). Lets watch the trend over the weekend and see if the temperature comes down and if the PMC / WFS variations get less. Fri May 14 17:46:26 2021

  16142   Sat May 15 12:39:54 2021 gautamUpdatePSLNPRO tripped/switched off

The NPRO has been off since ~1AM this morning it looks like. Is this intentional? Can I turn it back on (or at least try to)? The interlock signal we are recording doesn't report getting tripped but I think this has been the case in the past too.


After getting the go ahead from Koji, I turned the NPRO back on, following the usual procedure of diode current ramping. PMC and IMC locked. Let's see if this was a one-off or something chronic.

Attachment 1: NPRO.png
NPRO.png
  16144   Tue May 18 00:52:38 2021 ranaUpdatePSLHEPA speed raised

Looks like the fan lowered the temperature as expected. Need to get a few more days of data to see if its stabilized, or if that's just a fluke.

The vertical line at 00:00 UTC May 18 is about when I turned the fans up/on.

Attachment 1: Untitled.png
Untitled.png
  16145   Tue May 18 20:26:11 2021 ranaUpdatePSLHEPA speed raised

Fluke. Temp fluctuations are as usual, but the overall temperature is still lower. We ought to put some temperature sensors at the X & Y ends to see what's happening there too.

  16400   Thu Oct 14 09:28:46 2021 YehonathanUpdatePSLPMC unlocked

PMC has been unlocked since ~ 2:30 AM. Seems like the PZT got saturated. I moved the DC output adjuster and the PMC locked immidiatly although with a low transmission of 0.62V (>0.7V is the usual case) and high REFL.

IMC locked immidiately but IFO seems to be completely misaligned. The beams on the AS monitor are moving quite alot syncronously. BS watchdog tripped. I enabled the coil outputs. Waiting for the RMS motion to relax...

Its not relaxing. RMS motion is still high. I disabled the coils again and reenabled them. This seems to have worked. Arms were locked quite easily but the ETMs oplevs were way off and the ASS couldn't get the TRX and TRY more than 0.7. I align the ETMs to center the oplev. I realign everything else and lock the arms. Maximium TR is still < 0.8.

 

 

  16401   Thu Oct 14 11:25:49 2021 YehonathanUpdatePSLPMC unlocked

{Yehonathan, Anchal}

I went to get a sandwich around 10:20 AM and when I came back BS was moving like crazy. We shutdown the watchdog.

We look at the spectra of the OSEMs (attachment 1). Clearly, the UR sensing is bad.

We took the BS sattelite box out. Anchal opened the box and nothing seemed wrong visually. We returned the box and connected it to the fake OSEM box. The sensor spectra seemed normal.

We connected the box to the vacuum chamber and the spectra is still normal (attachment 2).

We turn on the coils and the motion got damped very quickly (RMS <0.5mV).

Either the problem was solved by disconnecting and connecting the cables or it will come back to haunt us.

 

 

 

Attachment 1: BS_OSEM_Sensor_PSD.pdf
BS_OSEM_Sensor_PSD.pdf
Attachment 2: BS_OSEM_Sensor_PSD_AfterReconnectingCables.pdf
BS_OSEM_Sensor_PSD_AfterReconnectingCables.pdf
  17   Fri Oct 26 09:10:17 2007 steveRoutinePEMPEM &PSL trend
The fires are out, lab particle counts are up.
Psl HEPAs are at 100% and mobel HEPAs are just turned on
20 days plot and 5 hrs plot below
Attachment 1: counts&psl.jpg
counts&psl.jpg
Attachment 2: 5dcounts.jpg
5dcounts.jpg
  83   Thu Nov 8 11:40:21 2007 steveUpdatePEMparticle counts are up
I turned up the psl HEPA filter to 100%
This 4 days plot shows why
Attachment 1: pslhepaon.jpg
pslhepaon.jpg
  114   Mon Nov 19 14:19:25 2007 steveOmnistructurePEMjackhammer
The construction personal successfully jackhemmered a fence around the "Drever's parking slot"
There is no parking space available close by
Attachment 1: jackhammer.jpg
jackhammer.jpg
Attachment 2: jackhammer2.jpg
jackhammer2.jpg
  151   Fri Nov 30 20:17:26 2007 AndreyConfigurationPEMAccelerometers and alum.plates for them
All 6 accelerometers which were located near the ITMX are turned off and disconnected from the power cords.
Actually these accelerometers are now in the office area on the electronics bench (to the left from Steve Vass' place).

I made today 4 new aluminum mounting plates for the accelerometers (I drilled holes and made threads in them). On Monday I will buy short screws and install accelerometers on these new mounting plates. These mounting plates will be screwed directly into the metallic frame which is firmly cemented to the ground. Before yesterday accelerometers were mounted on top of blue stack towers, not on the ground directly, so we hope that new measurements of the ground noise will be more realistic.

The 4 mounting plates are on the same desk -> on the electronics bench (to the left from Steve Vass' place). Please do not displace them.

Attached is a drawing of the aluminum mountain plate.
Attachment 1: Scheme_Aluminum_Piece-inches.pdf
Scheme_Aluminum_Piece-inches.pdf
  152   Fri Nov 30 21:27:24 2007 ranaDAQPEMweather / stacis / c1pem1
I was trying to add some Seis BLRMS channels to the c1pem1 processor so that we could have DMT trends.

Then I found that none of the Weather channels have been working for a year or so. I could also not
telnet into it. I tried resetting it but no luck. There was no entry in the Wiki for it so I added
a place holder.

Have the weather channels ever worked? Do we have those sensors? I think I've never actually looked
for this. Seems like a fine ugrad job.
  161   Mon Dec 3 19:44:58 2007 Accelerometers on new mountsConfigurationPEMAndrey

I (Andrey) continued today working with new accelerometer mounting. (see entry #151 about my Friday work).

I bought screws/washers and attached those mounts with accelerometers to metallic frames which are firmly cemented to the floor.

One such mount with three accelerometers (in X-, Y-, Z-directions) is installed near the ITMX (in the previous location, but NOT on top of the unused stack as before Friday), the other mount with three accelerometers in three orthogonal directions is installed near ETMX in the east end of the room (this set of accelerometers was installed between MC and BS before Friday). I uncoiled the cables, put them into the cable tray towards the ETMX, and hooked-up the three accelerometers near ETMX in the east end of the room.

Now all six accelerometers are hooked-up (that is, connected to power supply board with cables).

We decided with Steve Vass to put red cones (similar to those that are on highways in the road construction zones) in order to prevent people from bumping into accelerometers. Please use caution when walking along the X-arm.

I took several pictures of the new accelerometer setup. Picture "DSC_0194.JPG" shows the mount with accelerometers near the the ITMX and the beamsplitter chamber,
picture "DSC_0195.JPG" is the "zoomed-in" view of the same accelerometers, while picture "DSC_0196.JPG" shows the mount with accelerometers near ETMX in the east end of the room.

Many thanks to Mr. Steve Vass for his thorough explanation/showing me how to drill the metal and put threads in the holes.
Attachment 1: DSC_0194.JPG
DSC_0194.JPG
Attachment 2: DSC_0195.JPG
DSC_0195.JPG
Attachment 3: DSC_0196.JPG
DSC_0196.JPG
  172   Wed Dec 5 23:19:03 2007 AndreyConfigurationPEMAccelerometers are turned on

All accelerometers have been turned on, as Alan asked during Wednesday meeting.

Typical power spectra and coherence plots are attached below.

"East" in the name means that the previous location of accelerometrs was to the east from "Beamsplitter" (the location for "east" accelerometers was not changed, actually, it is still near ITMX), while "west" means that previously accelerometers were to the west from the BS, but now their new location is near the ETMX.

I will change the names of the channels tomorrow (Thursday) when someone (Tobin?) will show to me how to do it.

P.S. (addition made on Dec. 19th, 2007, by Andrey) I intended to change the names of accelerometers the next day, Thursday Dec. 06,
but I did not do it that day (did not understand how to do it), then I fell ill, and eventually
I changed the names of accelerometers on December 19th, see entry to ELOG #204)
Attachment 1: Power_Sp_and_Coh_XY-EAST.pdf
Power_Sp_and_Coh_XY-EAST.pdf
Attachment 2: Coherence-ZX_East.pdf
Coherence-ZX_East.pdf
Attachment 3: Coherence-ZY_East.pdf
Coherence-ZY_East.pdf
Attachment 4: Power_Sp_WEST.pdf
Power_Sp_WEST.pdf
Attachment 5: Coherence-ZX_West.pdf
Coherence-ZX_West.pdf
Attachment 6: Coherence-XY_West.pdf
Coherence-XY_West.pdf
Attachment 7: Coherence-YZ_West.pdf
Coherence-YZ_West.pdf
  189   Wed Dec 12 22:24:48 2007 tobinFrogsPEMweather station
I poked at the weather station briefly this evening.

* There's almost nothing in the elog about it.
* It exists. It is located on the North wall, just north of the beam splitter.
* It seems to be displaying reasonable data for the indoors, but nothing for the outdoor sensors.
* c1pem didn't seem to be starting up (couldn't telnet into it, etc). I altered its startup file and reset it several times, and eventually it came to life.
* the weather station has a serial cable that goes all the way to c1pem. I plugged it in.
* however, the Weather.st program complains "NO COMM"--it gets no data from the weather station
* The next thing to do is to plug in a laptop to that serial cable and see if the weather station can be convinced to talk.
  200   Wed Dec 19 11:31:01 2007 steveOmnistructurePEMaircond filter maintenance
Jeff is working on all air condiontion units of the 40m lab
This we do every six months.
Attachment 1: acfilters6m.jpg
acfilters6m.jpg
  204   Wed Dec 19 20:28:27 2007 AndreyDAQPEMNames for all 6 accelerometers have been changed

I eventually changed the names for all 6 accelerometers (see my ELOG entry # 172 from Dec. 05 about my intent to do that).

I removed the word "BS" from their names,
and I changed the word combination "ACC_BS_EAST" in the old name for "ACC_ITMX" in the new name;
as well "ACC_BS_WEST" is now replaced by "ACC_ETMX".
(the reasoning behind such a change should become clear from my ELOG entry #172).

New accelerometer names are:
(note: there are no spaces (nowhere!) in the names of accelerometers, but ELOG replaces ": P" written without a space by a strange symbol Tongue)

C1 : PEM - ACC _ ETMX _ X ;
C1 : PEM - ACC _ ETMX _ Y ;
C1 : PEM - ACC _ ETMX _ Z ;
C1 : PEM - ACC _ ITMX _ X ;
C1 : PEM - ACC _ ITMX _ Y ;
C1 : PEM - ACC _ ITMX _ Z .

One can find them in "C1 : PEM - ACC" in Dataviewer.

  255   Wed Jan 23 11:41:06 2008 steveUpdatePEMsulfur smell in 40m
Led - acid car batteries were overcharged in the machine shop next door
and sulfuric acid smell is coming over to the ifo room.

Entry room 103 is specially bad.
  258   Thu Jan 24 11:52:56 2008 steveUpdatePEMthe mud is cleaned up & MOPA shutter is opened
Safety glasses are required again!

I have just opened the mopa shutter.
One janitor came to help with muddy floor.
Rack 1x1 toward ITMX chamber and the south wall of these area
were completely covered by mud. I wiped the floor of bottom of the rack
with towels. The cables were lifted and still should be wiped.

The bottom of LSC rack got less water, only on the west side.

We are ready to bring up the computers.

Thanks to ALL with the clean up, including Alan Rice
who was really helpful.

  264   Fri Jan 25 09:22:21 2008 steveUpdatePEMburned toast award goes to
DYM for collaborating with the enemy.

In order to minimize the number of ants visiting our lab we have to take out side the lab
all food left over and organic waste. If you are eating here do not expect someone else
to clean up after you.

Thanks for your cooperation.
  283   Mon Jan 28 19:35:55 2008 ranaSummaryPEMAccelerometer and Seismometer Coherences
The attached PDF shows that there is some strange behavior at low frequencies.

From the plot it looks like to me that the Wilcoxon accelerometers (which are supposed to have good response down to 0.05 Hz) are not displaying real seismic motion below 0.3 Hz. Because the coherence length for seismic waves at those frequencies should be 100's of meters we should expect that the accelerometers would have good coherence (>0.8) down there. Instead, my guess is that its all air currents, temperature, or electronics noise. These sensors are not reliable indicators for the microseism.

The Ranger seismometer, however, seems to work fine down to just below the microseism. The Ranger is mounted down around the X end and pointing in the z-direction. The coherence I plotted between it and EX_Z is larger than any other acc/seis pair (as expected).

JM and I discussed what could be done; if we get a SURF student who's into building stuff we can ask them to make a styrofoam hut for the Wilcoxons to see if that helps anything. JM also asked what the point of all this is.

IF we want to do good Adaptive Noise subtraction then we need sensors which can sense the motion which disturbs the mirrors and they need to sense it with a good SNR to get a good subtraction ratio. If the styrofoam thing doesn't work, we should probably look into getting a Guralp 3-axis seismometer for the corner area and just move the accelerometers down to the ends. The sites have Guralp CMG-40T units (~ 8k$). I think we should check out the CMG-3T or the CMG-3ESP.

Does anyone know someone in the Geo depts that we can borrow one from?
Attachment 1: Acc.pdf
Acc.pdf
  295   Sun Feb 3 05:02:41 2008 ranaUpdatePEMSeism 4 day
Attachment 1: Screenshot.png
Screenshot.png
  298   Tue Feb 5 17:39:05 2008 jweinerConfigurationPEMPEM-AS_MIC taken down from AS table, will put in PSL enclosure soon
I took down the microphone that Andrey hung above the AS table his first week in lab. I want to hang the microphone above the PMC to check the effect of acoustic noise on the PMC. The cables were a little more tangled than I thought so I've only taken the microphone down and haven't hung it back up yet, but on Thursday I'll have enough time to carefully put it up inside the PSL and see what I can find out about acoustic noise inside the PSL. I think the microphone should be sensitive enough for the frequencies we're interested in, and I'll hopefully find out if it's sufficient once I put it up in the PSL. The microphone cable and microphone are on top of the PSL for now.
  299   Wed Feb 6 09:17:31 2008 steveUpdatePEMIST building construction continoues
The bulldosers at work
Attachment 1: seismic8d.jpg
seismic8d.jpg
Attachment 2: seisioo.jpg
seisioo.jpg
  303   Fri Feb 8 17:55:53 2008 joshConfigurationPEMPEM-AS_MIC now in PSL enclosure
I have moved the microphone to the PSL enclosure, hanging near the south (Y) side from a support rod for the overhanging storage area so that it's reasonably close to the PMC. I've fastened it in many places using cable ties to make sure that it won't fall.

Alberto helped me solder together a female BNC-female 3.5 mm stereo adapter so that I can use the DAQ to output through BNC to PC speakers. My plan is do sweep sine output through PC speakers to find the transfer function of sound from outside the enclosure to inside the enclosure and by moving the microphone more centrally over the PSL table, check if there are any strong resonances. Hopefully I can use this technique at other places around the interferometer or measure the effect of installing acoustic foam.
  308   Mon Feb 11 14:24:19 2008 steveUpdatePEMmore earthquakes
ITMX and ITMY sus damping restored after Baja earthquake 5.1 mag at 10:29 this morning.

The ground preparation for The ITS building is almost finished.
Activity is winding down, however the Baja California_ Mexico earthquake zone
"Guadala Victoria" started acting up on Friday.

http://earthquake.usgs.gov/eqcenter/recenteqsus/Maps/special/California_Nevada_eqs.php
Attachment 1: eqfeb11.jpg
eqfeb11.jpg
  324   Tue Feb 19 18:28:41 2008 JohnUpdatePEMMore seismic in Baja California
Steve spotted more activity from the same quake.

Reset watchdog on ETMY.
  330   Fri Feb 22 02:51:20 2008 AndreyUpdatePEMAccelerometer ITMX seems to be broken

As people probably know,

I am trying (for a long time) to create a computational program that calculates the evolution of accelerometer time-domain data through stacks and pendulum transfer functions to test masses, and calculate the RMS of differential arm lenght spectrum.

I noticed on Tuesday that time-domain signals from the two accelerometers (one is near ETMX, the other one is near ITMX) seem to have different amplitudes of fluctuations around the mean value. I suspected that this is the main reason why I cannot get the awaited result of minimum of RMS for equal values of Q-factors for ETMX and ITMX suspensions (because we subtract two very different numbers, so we cannot get anything close to zero). I took amplitude spectra of the accelerometer data (dttfft2), and they look very differently for ETMX and ITMX accelerometers. I believe that spectrum of ETMX accelerometer represents seismic noise, but accelerometer ITMX seems to provide us with irrelevant and wrong data. No peaks, just almost monotoneous decreasing curve, and 10 times smaller amplitude. Therefore, ITMX seems to be broken.

I will try tomorrow to clap my hands, shout, yell, near the broken accelerometer to confirm that the accelerometer is broken (more precisely, that either accelerometer itself is broken,
or cable connections, or DAQ channel, but something is wrong). Now it is very late, and I am going home.

See attached figures: time-scale is 10^(-1), 10^0, 10^1, 10^2 Hz.
Attachment 1: Accelerom-EYMX-Feb22.jpg
Accelerom-EYMX-Feb22.jpg
Attachment 2: Accelerom-ITMX-Feb22.jpg
Accelerom-ITMX-Feb22.jpg
  336   Fri Feb 22 15:16:33 2008 AndreyUpdatePEMITMX Accelerometer is NOT broken

As I wrote in message 330, there was a bad signal from ITMX accelerometer. I have found the reason: the BNC-cable which goes from the black board with switches for accelerometer gain (1,10,100) towards DAQ-tower was completely disconnected from that black board with gain-switches. The end of the long BNC-cable was on the floor. Therefore, it was totally impossible to see any accelerometer signal. The cable that I am writing about should transport the signal from ITMX_X accelerometer.

Now all the BNC-connections seem to be in good shape, and spectra of accelerometers near ITMX and ETMX , both of them are in x-directions, are very much similar.
Attachment 1: Accelerom-ITMX-Feb23.jpg
Accelerom-ITMX-Feb23.jpg
Attachment 2: Accelerom-ETMX-Feb23.jpg
Accelerom-ETMX-Feb23.jpg
  363   Fri Mar 7 00:47:54 2008 ranaConfigurationPEMRanger SS-1
Yesterday evening around 7:30 PM, I changed the Ranger seismometer from a
vertical to a horizontal seismometer. To do this I followed the instructions
in the manual.
1) Lock it down.
2) Turn it sideways. Use the leveling screws to center the bubble level.
3) Carefully loosen the hanger rod and release slowly the tension to allow
   the mass to recenter.
4) Look through the little viewhole next to the rod to make the white lines
   line up. This means the mass is centered.
5) Look at the output on a scope. It should be freely moving with a ~1 sec.
   period.

The attached plot shows the before and after spectra.
Attachment 1: ss1.pdf
ss1.pdf
  368   Tue Mar 11 23:14:01 2008 ranaConfigurationPEMAccelerometer and Seismometer movements
Steve and Matt moved the accelerometers and seismometers today.
The accelerometers are now placed around the MC and the seismometer is in-between MC1 & MC2.

We have changed the names of the acc channels to reflect whether they are close to MC1/MC3
or MC2. We tested the accelerometer to channel name mapping by switching gains at the wilcoxon
breakout box and also by tapping. It seems now that the previous setup near the ITMX/ETMX had
some few channels mislabeled which would have given some confusing results.

Alex, Jay, and Rolf came over today and installed, then de-installed some of the hardware for
sending the PEM channels over to the C1ASS machine where the adaptive filter front end will go.
Everything should be back to the way it was...hopefully, the guys will modify the ADCU PEM
code to send the signals to the new FE over the reflective memory net and then send them to the
MCL inputs of the suspensions. So the first incarnation should use the accelerometers and seismometer
to drive MC1 and/or MC3.
Attachment 1: Acc.pdf
Acc.pdf
  369   Wed Mar 12 00:36:52 2008 ranaConfigurationPEMAccelerometer and Seismometer movements
I used the MISO FIR Wiener matlab code to see how well we might do in principle.

The attached 3 page PDF file shows the MC_L control signal (force on MC2) and the residual
after subtracting off the accelerometer and seismometer using a 32 Hz sample rate and
512 taps (page 1), 1024 taps (page 2), and 2048 taps (page 3). As Matt smarmily points out,
there's not a lot to win by going beyond 512; maybe a factor of sqrt(2) for a factor of 4
tap number.
Attachment 1: finished.pdf
finished.pdf finished.pdf finished.pdf
  370   Wed Mar 12 00:40:35 2008 ranaConfigurationPEMAccelerometer and Seismometer movements
Same as above but with 2048 taps and a 128 Hz sample rate. Does much better at the 16 Hz bounce mode.
Attachment 1: mc2048-128.pdf
mc2048-128.pdf
  371   Wed Mar 12 00:47:26 2008 ranaConfigurationPEMAccelerometer and Seismometer movements
And this is a cool snapshot showing how this operation used 16 cores on menkar !
Attachment 1: Screenshot.png
Screenshot.png
  384   Mon Mar 17 18:30:48 2008 mevansConfigurationPEMAdaptive Filtering
It seems that adaptive filtering can achieve results similar to those of the MISO FIR Wiener (entry 369). The adaptive code simulates real-time operation, but uses the same data used by Rana for the Wiener filter. I ran the adaptive filter over the data 100 times to ensure that it was well trained... maybe too well.
Attachment 1: mcacc_adaptive.png
mcacc_adaptive.png
  391   Fri Mar 21 23:15:11 2008 ranaConfigurationPEMRanger SS-1: New Setup
The Ranger seismometer has been in a bad state. Its output had been sent into a SR560 without any termination.

The seismometer is, internally, just a mass on a flexure with a magnet and a pickup coil for readout.
The damping of the system depends on the resistor hooked up across the coil. With the SR560 this is
the 1 Meg input impedance of it and so the mass is undamped.

I installed a 4300 Ohm resistor in there which seems to nearly critically damp it. However, this will not
allow us to reach the ultimate quantum noise limited performance. We will have to analyze the thermal, voltage,
and current noise to get that.

I then also increased the gain from 10 to 100 on the SR560. This should now make the front end noise of the
seismometer/SR560 close to equal to the noise of the PEM ADC.
  418   Tue Apr 8 09:08:54 2008 steveConfigurationPEMweather station disconnected
We can not leave cables in the walkways and go on vacation.
I disconnected the weather station from the DAQ
Every Tuesday is janitor day in the 40m.
We have to give him free space for doing a good job.

Burned toast award goes to Andrey.
Attachment 1: toast.jpg
toast.jpg
  420   Wed Apr 16 09:47:35 2008 AndreySummaryPEMWeather Station
The weather station is functional again.

The long ethernet Cat5 cable connecting 'WeatherLink' and processor 'c1pem1' was repaired yesterday, namely the RJ45 connector was replaced,
and information about weather conditions is now again continuously being transferred from the 'Weather Monitor' to the control UNIX computers. We can see this information in 'c0Checklist.adl' screen and in Dataviewer.

Below are the two sets of trends for the temperature, wind speed and direction, pressure and the amount of precipitation.

The upper set of trends ("Attachment 1") is "Full Data" in Dataviewer for the 3 hours from 6.30AM till 9.30AM this morning,
and the lower set of trends ("Attachment 2") is "Minute Trend" in Dataviewer for 15 hours from 6.30PM yesterday till 9.30AM this morning.

I also updated the wiki-40 page describing the Weather Station and added to there a description of the process of attaching the RJ45 connector to the end of ethernet Cat5 cable. To access the wiki-40 page about the "weather station" you should go from the main page to "PEM" section and click on "Weather Station".
Attachment 1: Weather-FullData_3hrs.png
Weather-FullData_3hrs.png
Attachment 2: Weather_Trend_15hrs.png
Weather_Trend_15hrs.png
  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.
  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.
Attachment 1: DSC_0520--before.JPG
DSC_0520--before.JPG
Attachment 2: DSC_0537--after.JPG
DSC_0537--after.JPG
  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
  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.
Attachment 1: Microphone.png
Microphone.png
  452   Sat Apr 26 01:45:38 2008 AndreySummaryPEMWeather Station enhancement
Two more things concerning weather monitoring have been done during this week.

1) A Dataviewer template was created, so that it allows to see "real-time" information from weather channels immediately, without adding many channels "manually".

If one wants to use this template,
open Dataviewer -> "File" -> "Restore Settings", /cvs/cds/caltech/users/Templates/Dataviewer_Templates/Weather.xml.

2) I wrote a couple of Matlab scripts that allow to read data (minute trends) from the Dataviewer channels over some time in the past, save the received data in mat-files, and plot those minute-trends. Thus, one can get plots that are very much similar to what one can see in Dataviewer. These two Matlab files are located in the directory
"/cvs/cds/caltech/users/weather_station". File "WeatherReading.m" allows reading from the weather channels (paths to mDV directory must be configured before using my script), file "WeatherTrends.m" allows plotting of those minute trends.

Unfortunately, hardware problems arise very often if we want to read for a somewhat long time in the past, so until now I have not succeeded in getting trends for more than 20 minutes. As an example, see the attached png-file with the 20-minutes trends of data from Thursday evening.

3) So far I did not have success in learning how to recalculate pressure from Pascals to mbars in EPICS (although I tried google-search).

4) I am making every effort in recent weeks not to put any personal or non-scientific information into elog, but this message could be important for all of us, so I cannot resist:
a shark in the Pacific Ocean has killed a swimmer near San-Diego (I saw this in russian news and then made a quick google-search).
http://latimesblogs.latimes.com/lanow/2008/04/this-just-in-fa.html
Attachment 1: Matlab_Weather_Trends.png
Matlab_Weather_Trends.png
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