40m QIL Cryo_Lab CTN SUS_Lab CAML OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log, Page 87 of 354  Not logged in ELOG logo
ID Date Author Type Categorydown Subject
  17297   Tue Nov 22 08:56:27 2022 JCUpdatePSLPMC input beam alignment

[Paco, Anchal, JC]

C1:PSL-PMC_PMCTRANSPD ~ 0.715 this morning, this was increased to ~0.730. There also seems to be an earthquake going on and the MC is flashing.

Attachment 1: Screenshot_from_2022-11-22_08-58-45.png
  17316   Mon Nov 28 11:21:25 2022 JCUpdatePSLPMC input beam alignment

C1:PSL-PMC_PMCTRANSPD was increased from 0.72 to 0.731

Attachment 1: Screenshot_from_2022-11-28_11-20-31.png
  17390   Tue Jan 10 16:06:58 2023 yutaSummaryPSLPMC transmission dropped to 0.68

[JC, Paco, Yuta]

It seems like PMC transmission (C1:PSL-PMC_PMCTRANSPD) dropped to ~0.68 from ~0.74 on Dec 27.
We tried to tweak PZT offset for PMC loop and input alignment to PMC, but PMC transmission didn't increased.
PSL laser temperature was also sweeped in the range 30.3 - 31.6 degC, but didn't help. The PSL temperature was reverted to original 30.61(1) degC.
Power measured at PSL output now is 893 mW (measured at our standard place shown in 40m/16672), which used to be 951 mW in June 2022 (40m/16886).
Power measured at PMC input (see attached photo) now is 1.18 W.

 - What was the previous PMC input power we had?
 - Sweep PSL laser temperature for larger range

Attachment 1: Screenshot_2023-01-10_14-26-46.png
Attachment 2: IMG_1994.JPG
  17426   Thu Jan 26 16:07:05 2023 yutaSummaryPSLPMC aligned, now PMC transmission is 0.7

PMC aligned (Attachment #1).
Over the past month, PMC transmission is actually slowly growing from 0.68 to 0.70 (Attachment #2), since it suddenly dropped from 0.72 on Dec 27 (40m/17390).

Attachment 1: Screenshot_2023-01-26_16-10-20.png
Attachment 2: Screenshot_2023-01-26_16-10-35.png
  17433   Mon Jan 30 10:59:15 2023 JCSummaryPSLPMC aligned, now PMC transmission is 0.7

PMC hit a drop around mid-day on Saturday and has been going down since. As of now,


I will go in and adjust now.

Attachment 1: Screenshot.png
  17597   Fri May 19 13:25:03 2023 KojiUpdatePSLMCF Noise

This is super! And now is the time to replace the internal fan!


  17598   Fri May 19 15:25:00 2023 MayankUpdatePSLPSL tripped - removed internal fans

We removed the PSL controller internal (broken) fans after it tripped due to overheat.


[Mayank, Radhika]

While aligning Xarm I noticed sudden loss of beam. On Radhikas suggestion we cheked the PSL and found out that the PSL controller was in off state (No lights on front and back panel). We restored the situation by unplugging and replugging the power cord. The PSL worked fine for a few minutes (~ 30 ) and then tripped again.This time the front panel  OFF light was on . See attached image (Attachment #1).


[Paco, Mayank, Koji-remote]

We disconnected the PSL controller and took this opportunity to investigate the controller's internal cooling mechanism. After disassembling the top panel of the chassis, we saw there are two SUNON - KD1205PHB2 fans meant to run at 12 VDC (1.7 W) connected to the bottom pcb inside the controller. After disconnecting them from this board, we tested them with an externally supplied dc voltage and confirmed they no longer worked. We noted the cooling mechanism is based on a long aluminum heat sink to which most ICs are attached, and the fans are meant to provide airflow towards the rear aperture on the chassis. We followed Koji's suggestion and for now, removed the damaged components (detailed pictures of this operation have been posted in a google photos album elsewhere) to allow heat to flow out more easily.  We reassembled the controller chassis and reinstalled it with the external fan providing the necessary airflow to prevent the unit from tripping again due to overheating. Then we turned on PSL and recovered PMC and IMC locks.


We took a C1:IOO-MC_F_DQ trace after this work to confirm our earlier findings; the trace is attached in Attachment #2. The noise bumps are present as expected. This is still not a desirable configuration so next step would be replacing the external fan, or even better, find the appropriate spare of the internal units and berid the external one.

Attachment 1: 20230519_123659.jpg
Attachment 2: afterfans_PSLcontroller_Screenshot_2023-05-19_15-48-04.png
  17605   Fri May 26 15:04:12 2023 JCUpdatePSLPSL Fans Replaced

We Changed The Fans on the PSL

To start, the part Koji ordered is 259-1818-ND from DigiKey. This is a Maglev fan from SUNON that should give us less noise. We have 3 spare replacement fans in case these go bad which are stored in the ___ Cabinet along the Y arm (This will be updated once I find a suitable storage spot for the part.)

Starting the replacement process.

Removing the PSL 

    1. Our first step to doing this was to prepare for removing PSL. We began by doing a 60s MC WFS Relief. This will allows us to turn off WFS and close the PSL Shutter next. This is to prevent a large kick once we place the PSL back in its place. 
    2. Went to the PSL and mushed the off button and turned the key. After this, begin by removing the external fan which is shown in elog 17595. After, continue by unplugging the cables from the back beginning with the power cable. Attachment #1 shows the original positions of the cables connected before removing any. Keep in mind, DO NOT TO TOUCH THE KNOBS. If the inputs are changed, this will throw off the beatnotes of the AUX lasers.
        a. There is a black plug at the bottom with a screw hat is hard to reach. Be very patient taking this off because the position of the cable blocks a screqwdriver from untightening the screw. 
        b. A second person should be on the other side of the table to push the module back into arm's reach. Also to make sure the module does not slide back and fall. 
    3. After removing the module, bring into the control room and place onnto the workbench. Make sure all of the red lights are off and the PSL table is closed properly.

Changing the Fan 
    1. We removed the top cover of the module and opened it all up. Similar to what is shown in elog 17452.
        a. Keep in mind to wear a grounding wristband when working on this.
    2. After removing the old fans and attempting to install the new ones, the holes did not line up correctly (Shown in Attachment #2). To accomodate for this, we used 6-32 screws which gave us just enough slack to fit in all 4 corners.
    3. Ones the fans were bolted down onto the aluminum plate, I soldered the cables to connecting the fan cable to the cables those of the original PSL fans.
    4. Next I used heat shrinks to cover the bare soldered areas and placed the fans into the module. 
    5. We tested the fans by plugging intp the PSL and turning the key. The fans turned on nicely and we proceeded to put it module back together.

Placing the PSL back in its place. 

    1. We place the PSL back into its original spot and began to connect the cables. Make sure the Power cables is put in LAST. 
    2. After the module was put back, we DID NOT put the external fan back into its place. This is to see if the fans which were installed are good enough to maintain the PSL.
    3. Turn the key and press the on Button.

The noise from the external fan is no longer appearing as shown in attachment #3. The PSL has been on for ~2 hrs now and has not turned off. It seems that the fans are doing their jobs well. 


Attachment 1: IMG_5650.jpeg
Attachment 2: IMG_5653.jpeg
Attachment 3: Screenshot_2023-05-26_16-25-54.png
  17697   Wed Jul 19 15:52:43 2023 HirokiUpdatePSLRestored PMC alignment

I found that the MC transmission was low (~13000. Usually it's ~13500) in the morning.
This was due to the low transmission of PMC (~0.675. Usually it's ~0.685), so I restored the PMC alignment using the two steering mirrors before the input mirror.
The transmission of MC and PMC was restored to ~13300 and ~0.687.

  17743   Tue Aug 1 21:52:46 2023 HirokiUpdatePSLRemote switching of PSL shutter is not working

[Yuta, Hiroki]

Remote switching of PSL shutter is not working.

When we tried to reset the LSC offsets, we found that the remote switching of the PSL shutter was not working.
We closed the shutter manually by using the toggle switch on the front panel of the shutter driver (N.C. -> N.O. (Attachment 1)) for the momment.

Attachment 1: PSLshutterDriver.jpg
  17746   Wed Aug 2 14:50:22 2023 KojiUpdatePSLFIXED: Remote switching of PSL shutter is not working

[JC Koji]
c1vac was hard rebooted. This fixed the PSL shutter issue.

  • Checked the Unibritz Shutter Controller for the PSL shutter. It seems that it responds to the NO/NC switch no matter how the REMOTE/LOCAL switch is. (Normal action)
  • Checked the BNC input to the shutter controller. There was no trigger/gate or whatever signal from Acromag.
  • c1psl reboot did not help
    • Upon this action, a snapshot was taken.
    • Stopped/restarted modbusIOC.services. Did not work.
    • Rebooted c1psl. Didn't work.
  • c1psl was shutdown and c1psl acromag chassis was power-cycled. This didn't help. c1psl was burtrestored.
    • Stopped modbusIOC.services. Shutdown c1psl.
    • Power cycled the Acromag chassis.
    • After a while, c1psl was turned on. The epics channels came back.
    • Confirmed modbusIOC.services was running.
    • Burtrestored the snapshot.
  • I remembered that the vacuum pressure could make an interlock action on the PSL shutter.
    Found that c1vac values were all whited out. c1vac was not reachable from Martian.
  • Went to c1vac and found it was frozen. Pushed hard reset.
  • c1vac came back, and it closed the gate valve V1 (main GV for the main vacuum manifold). We opened V1 from the vac control screen.
  • Confirmed the PSL shutter is now operational.
  17748   Wed Aug 2 17:17:37 2023 KojiUpdatePSLIMC Locking (FIXED: Remote switching of PSL shutter is not working)

After the exploration of c1psl, the IMC locking was not functioning well. It looked like the MC autolocker issue.

Now I remember that the autolocker was running on docker. I followed the instruction on the wiki page. https://wiki-40m.ligo.caltech.edu/Computers_andScripts/AlwaysRunningScripts

Remember: Docker is running on optimus / systemctl is running on megatron!

Then: I noticed that MC autolocker heartbeat was blinking even with the docker stopped (!?). I confirmed that autolocker is not running on systemctl

I had no hope who is toggling the heartbeat, but "ps -def" on megatron showed me that "AutoLockMC_LowPower.csh" is running! I was afraid that it is a remnant from vent!? But, is that possible?

The process was killed and the docker locker is running well now.

  17761   Tue Aug 8 01:07:52 2023 HirokiUpdatePSLTesting and wiring the PSL Flow speed sensor

For monitoring the statuses of the PSL HEPA fans, we are planning to attach flow speed sensors (D6F-V03A1) on the HEPA fans.
Before installing the flow sensors, I have finished the followings:

  • Tested two flow sensors with alligator clip wires (Attachment 1)
    • No flow: ~ 0.5 V
    • Saturation: ~ 2.7 V
  • Measured the flow speed of PSL HEPA fans with an alligator-clip-wired flow sensor
    • Medium speed: ~ 0.8 V (~ 0.6 m/s )
    • Maximum speed: ~ 1.4 V (~ 1.8 m/s)
      The flow speed [m/s] was estimated from the linear approximation of the nominal value
  • Wired flow sensors to install them in PSL and to take the output voltage by an Acromag ADC (Attachment 2)
    • Wired sensors worked as in the case of the alligator-clip-wired sensors.


  • Summarize the details of the used parts and the wiring.
  • Install the wired flow sensors in PSL. Monitor their outputs from CDS.
Attachment 1: AlligatorTest.jpg
Attachment 2: WiredFlowSensor.jpg
  17765   Wed Aug 9 02:54:06 2023 HirokiUpdatePSLInstalled PSL Flow speed sensor

[Paco, Hiroki]  

Installed two flow sensors on the PSL HEPA fans 

To monitor the flow speed of the PSL HEPA fans, we installed two flow sensors:

  • Attached two flow sensors on the ceiling of PSL table and connected their outputs to the Acromag ADC:
    • Attachment 1: Connected DB37 to the Acromag ADC
    • Attachment 2: Wiring from the Acromag ADC to the PSL table
    • Attachment 3: Attached flow sensors on the ceiling of the PSL table
    • Attachment 4: Wiring diagram
  • Changed the flow speed of HEPA fans and monitored the signals from the corresponding sensors with StripTool (Attachment 4):
    • ​Sensor 1:
      • Minimum speed: ~ 0.52 V 
      • Medium speed:   ~ 0.78 V 
      • Maximum speed: ~ 0.83 V 
    • ​Sensor 2:
      • Minimum speed: ~ 0.50 V 
      • Medium speed:   ~ 0.72 V 
      • Maximum speed: ~ 0.83 V 

The results above are non-linear. This might be due to the non-linearity of the flow sensors and the non-linearity of the controllers for HEPA fans.
*Regarding the HEPA fan 1, which the sensor 1 is attached on, there was slight flow even when the speed was minimized. This is why the minimum output of sensor 1 was ~ 0.52 V and not 0.50 V.


  • Calibrate the Acromag ADC by injecting signal from a function generator.
  • Calibrate the measued voltage to the flow speed (with linear approximation?) and show them on the CDS screen.
Attachment 1: ToAcromagAI.jpg
Attachment 2: WiringToPSL.jpg
Attachment 3: InsidePSL.jpg
Attachment 4: Screenshot_20230808_161356.png
Attachment 5: FSwiring.pdf
  17778   Fri Aug 11 20:44:00 2023 KojiUpdatePSLCDS crash / PMC recovery and mystery / IFO recovery

[JC, Koji]

In the morning, JC came in and found that c1sus had crashed. JC tried to save the situation by rebooting the host, inevitably, all the CDS machines needed to be rebooted.
But it was successful! Thanks, JC!

The remaining issue was that the PMC was in a strange state.
- The transmission was low (0.45~0.5V vs 0.67~0.68V nominal)
- The input alignment didn't help much
- The refl spot was not well centered on the CCD

We jiggled the setting for a while and found that the PMC error input offset needs to be significantly increased from the nominal value.
In fact, the offset hit the end of the range (+10V), this made the transmission to be ~0.67, but there may be slight room to improve it.
To investigate this, we need to look at the analog error signal, but I don't have enough energy to look into it today.

After the PMC recovery, the IMC was locking already, and the arms were flashing. I took the alignment of both arms.

Attachment 1: Screenshot_2023-08-11_22-04-41.png
Attachment 2: Screenshot_2023-08-11_at_23.09.49.png
  17779   Sat Aug 12 02:21:12 2023 HirokiUpdatePSLCalibrated PSL Flow speed sensor

[Koji, Hiroki] 

Calibrated flow sensor signals from [volt] to [m/s] and displayed them on CDS screen

We added the EPICS calc records to /cvs/cds/caltech/target/c1psl/psl/pem.db (Attachment 1) and made two channels for the calibrated signals of the flow sensors as follows:

C1:PEM-HEPA_FLOW_PSL1_CAL : Calibrated signal of flow sensor 1 [m/s]
C1:PEM-HEPA_FLOW_PSL2_CAL : Calibrated signal of flow sensor 2 [m/s]

At first, we tried to calibrate the output signal by using the 6-order approximation written in the user's manual (P11, D6F-V03A1) but the resulting outputs became 0 and we failed.
The cause of this failure might be due to the large number of the calculation of the 6-order approximation.
Then we used 5-order approximation that was fitted to the 6-order approximation and succeeded in obtaining the calibrated signals.
The used 5-order approximation is as follows:

Flow\ speed\, [\mathrm{m/s}] = Av^5 + Bv^4 +Cv^3 +Dv^2 + Ev + F
    v: output voltage from flow sensor [V]

Attachment 2 shows the time series data of the raw signals and the calibrated signals when the flow speed was changed in minimum - middle - maximum.
Attachment 3 shows the CDS screen displaying the calibrated signals.


Attachment 1: Screenshot_2023-08-12_02-23-04.png
Attachment 2: Screenshot_2023-08-12_09-15-17.png
Attachment 3: Screenshot_2023-08-12_02-43-52.png
  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
Attachment 2: 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
  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
Attachment 2: 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
  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
Attachment 2: DSC_0195.JPG
Attachment 3: 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
Attachment 2: Coherence-ZX_East.pdf
Attachment 3: Coherence-ZY_East.pdf
Attachment 4: Power_Sp_WEST.pdf
Attachment 5: Coherence-ZX_West.pdf
Attachment 6: Coherence-XY_West.pdf
Attachment 7: 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
  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
  295   Sun Feb 3 05:02:41 2008 ranaUpdatePEMSeism 4 day
Attachment 1: 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
Attachment 2: 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.

Attachment 1: 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
Attachment 2: 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
Attachment 2: 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.

The attached plot shows the before and after spectra.
Attachment 1: 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
  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
  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
  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
  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
  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
Attachment 2: 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
Attachment 2: 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
ELOG V3.1.3-