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Entry  Mon Sep 13 21:52:53 2010, kiwamu, Update, Green Locking, the X end laser is ON 

 I turned ON the laser at the X end station, which had been OFF for several weeks because of the crane business.

Now the green beam hits the ITMX and I got a reflection back to the end table.   

This green beam will be a nice reference when we install the green periscope in the chamber.

If it's necessary, feel free to correct the alignment of the green beam during my absence.

    Reply  Tue Aug 30 09:51:37 2016, Steve, Update, SUS, the chamber HEPA tents are back ETMYtentHEPA.jpgvented_for_60_days.png

How to minimize particles entering the vacuum envelope.

 

Just the way it was in August 2011 vent and before.

The portable HEPAs were set up at ETMY and ITMY with CP STAT 100 curtains.

The  40m particles on the floor at ITMY 3000-5000 counts  of 0.5 micron cf / min and 0.3 micron size particles are 55,000 - 65,000 counts cf / min

At this condition the MET One Counter #3 on the floor inside the tent goes to zero count  of 0.5 micron and 20-40 counts cf / min  for 0.3 micron when the tent is slightly overpressured.

 

 

 

 

 

    Reply  Wed Aug 31 23:01:02 2016, gautam, Update, SUS, the chamber HEPA tents are back 

Some more numbers we found while working in/around the chamber today:

Particle counts
Area 0.3 micron count (per cfm) 0.5 micron count (per cfm)
Vacuum chamber (vented) ITMY  ~5000 ~600
HEPA enclosure on ITMY door <100 0
Lab ~100,000 ~6000

These numbers were measured using our particle counter, which has a pump rate of 0.1 cfm, so the numbers above are 10x the numbers shown on the instrument after a measurement to account for this.

Essentially, the chamber is pretty dirty. Peeling the F.C with hard to reach optics like the ITM installed in place is not really feasible, and after peeling the F.C, we are looking at a best case of an additional 1-2 weeks in air to align the IFO, during which the optic is apparently exposed to quite a lot of particulates. In fact, with the high intensity flashlight left on, I actually saw some flecks of dust occassionally floating around inside the chamber while I was working on the optic. But this is just something we have to accept I guess.

Entry  Thu Dec 23 08:54:32 2010, Suresh, Update, elog, the delhi univ syndrome 

Sorry folks!  I couldnt get to the elog and didnt know that the elog was crashing every time I tried to access it. 

But have found other means to access it and the elog is safe for now!

Entry  Mon Aug 4 12:12:20 2008, steve, Configuration, VAC, the ifo is at atm vent3h.jpgUntitled.png
The 40m vac envelope was vented this morning.
P1 is at 760 Torr
Entry  Mon Aug 22 16:33:32 2016, Steve, Update, PEM, the lab temp is up temp.png

The IFO room temp is up a bit and it is coming down. The out side temp is not really high.

    Reply  Mon Aug 22 18:35:16 2016, Praful, Update, PEM, the lab temp is up temp_plot.pngtemp_plot.pngtemp_plot.png

The temperature is decreasing slowly but is still above 24 C.

temp_plot.png

Quote:

The IFO room temp is up a bit and it is coming down. The out side temp is not really high.

 

    Reply  Fri Oct 7 15:36:03 2016, Steve, Update, PEM, the lab temp is up tempUp.pngPEM4d.png

The IFO room temp is up

Quote:

The IFO room temp is up a bit and it is coming down. The out side temp is not really high.

 

Entry  Fri Nov 2 08:59:30 2007, steve, Bureaucracy, SAFETY, the laser is ON 
The psl laser is back on !
Entry  Thu Feb 21 09:56:26 2008, steve, Update, PSL, the laser is back laserisback.jpg
The laser and the psl recovered.
The water chiller temp is 19.98C and head temp 18.4C
Power 3.2W
PMC_T 3.1

c1iovme was restarted and the mc is locking now
Entry  Fri May 29 18:57:09 2009, steve, Update, PSL, the laser is back laserisback.jpg

Steve, Rob and Alberto

 

Starting capacitor 216 miroFarad was installed on the compressor. Water lines were connected to the MOPA as corrected, so the flow meter readings are logical.

Now IN means flowing water in the direction of black arrow on the hose.

We struggled with the Neslab presetting:  temp, bauds rate  and other  unknowns  till Rob found the M6000 manual on Peter king's website.

Alberto realized that the chiller temp had to be reset to 20C on water chiller.

I put 1mg of Chloramin T into the water to restrict the growth of algae in the bath.

The NPRO heat sink  was around ~20C without flow meter wheel rotation  and the PA body ~25C by touch of a finger

I just opened up the needle valve a litle bit so the flow meter wheel would started rotating slowly.

That small glitch at the end of this 3 hrs plot shows this adjustment.

Entry  Wed Feb 20 16:24:37 2008, steve, Update, PSL, the laser is recovering slowly laserecoverring.jpg
Head temp is still 20.5C and decreasing slowly.
Power output 2.9W
NPRO power 22 mW is increasing as head is cooling down
Entry  Thu Jan 24 11:52:56 2008, steve, Update, PEM, the 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.

Entry  Tue Nov 23 10:48:31 2010, Koji, Update, IOO, the plan of the day 

[Kiwamu/Koji]

- The tanks are open

Plan

[done] - Remove the PZT cable currently underlying between BS and ITMY chambers
[done] - Put this PZT cable between BS and IMC chambers. Connect it on the PZT on the IMC table (SM1)
[done]- Put the two OSEM cables between BS and ITMY chambers. Connect this cable to SRM.
  The connector for this cable at the BS side is coming from Bob's place on Wednesday. We left it disconnected for now.

- Energize all of four PZTs and check the functionality.

Entry  Mon Sep 8 10:57:49 2008, steve, Update, IOO, the psl and mc are back to normal fss.pngpmcbrick.pngbrick.jpg
The alarm handler is silent this morning.
This is almost unbelievably pleasant after two mount of harassment.
The MC did not lose lock for three days.

Atm1: the new fss layout
Atm2: PMC with lead brick
Atm3: 3 days plot
    Reply  Wed Jan 10 09:49:28 2018, Steve, Update, PEM, the rat is back 

Five mechcanical traps set inside of boxes. Red-white warning tape on top of each.

Quote:

Last jump at rack Y2.

 

Entry  Mon Oct 29 09:16:31 2007, steve, Routine, VAC, the rga is back rgaisback.jpg
We had no filament current since last power glitch of Oct. 8, 2007
First I thought that the filament was lost, but it was only bad contact.
The rga head pins were oxidized. Rga was turned back on last Friday.
It's temp is 55.3C normal
Entry  Thu May 28 18:41:26 2009, steve, Update, PSL, the saga of the chiller is ending 

I drained the water and removed side covers from the Neslab RTE 140 refrigerated water cooler unit this morning. The hoses to the laser were disconnected.

This abled you to see the little window of refregerant  R404A was free of bubles, meaning: no recharge was needed.

The circulator bath was refilled with 7 liters of Arrowhead distilled water and the unit was turned on.

The water temp was kept 20.00+- .05C without any load. Finally the AC-repair man Paul showed up.

He measured the R404A level to be as specified: 23-24 PSI on the suction side and 310 PSI on the discharge side.

The unit was working fine. Paul found an intermittently functioning starting capacitor on the compressor  that was removed.

The 240 micro Farad 120VAC cap will arrive tomorrow

    Reply  Wed Sep 9 10:13:31 2009, steve, Bureaucracy, General, the use of FAX machine, scanner & toaster 

 

 You said that the use of FAXST was forbidden for phds and graduate students. I had to swear on the promise of not ever buying an other FAXST

    Reply  Fri Jun 29 11:02:00 2012, steve, Update, VAC, the vent is at 500 torr sussum.pngpzt.png

Quote:

 Steve, Yuta and Jamie

Jam nuts were checked and oplev servos were turned off. Sus summery is below with strain gauge values. Are the strain gauge values have any meaning when the PZT contorrels are off??????????????????

    Reply  Tue Jul 23 14:00:03 2013, Steve, Update, VAC, the vent is completed Atm.png5cyl.pngventSum1d.png

 The 40m IFO has reached  atmospher in 5 hours. It is ready to open chamber condition. The RGA is pumped with the maglev.

P1 pirani gauge is contact dependent as you see it on the linear plot It will be replaced during this vent.

The venting speed was 2-4 Torr / min

Atm2 shows how the BS is sensing the venting air cylinder changes. 

The 4th cylinder of instrument  grade air  bump is overlapping with our janitor working at the BS chamber.

 

 

    Reply  Wed Feb 24 09:06:25 2016, Steve, Update, Treasure, the way it happened IMG_0120.JPG

 Celebration

Quote:

   Beautifully Done

   Chirp

  what is next?

Atm 3, Ron Drever could not celebrate with us because of health issues.

 

 

Entry  Thu Apr 16 16:37:42 2009, Alberto, Update, Auxiliary locking, the zipper  19_3f_Current_40m_plots_SUCCESS.pdf

It takes 18 months to double the computational power of microprocessors but it took man thousands of years to invent the zipper. I never really understood that till these days.

Here is a sample of my latest results from Optickle simulations of the locking signal for the Power Recycling Cavity.

Thanks also to Rob's revolutionary bidimensional rotating matrix idea (I can see entire books of linear algebra going to be rewritten now because of that) I could find the way to determine the optimal demodulation phases for the demod signals.

There were also an other couple of missing details. But that came easily along.

The parfor function for the parallel computation in Matlab sped up some loops by a factor of 100.

 

In these particular plots there's still no CARM offset scan. That's what I'm going to post next on the elog, together with the signals for the other degrees of freedom.

    Reply  Thu Apr 16 17:19:44 2009, Alberto, Update, Auxiliary locking, the zipper  04_3f_Current_40m_plots.pdf11_3f_40mUpgrade_plots.pdf

Quote:

It takes 18 months to double the computational power of microprocessors but it took man thousands of years to invent the zipper. I never really understood that till these days.

Here is a sample of my latest results from Optickle simulations of the locking signal for the Power Recycling Cavity.

Thanks also to Rob's revolutionary bidimensional rotating matrix idea (I can see entire books of linear algebra going to be rewritten now because of that) I could find the way to determine the optimal demodulation phases for the demod signals.

There were also an other couple of missing details. But that came easily along.

The parfor function for the parallel computation in Matlab sped up some loops by a factor of 100.

 

In these particular plots there's still no CARM offset scan. That's what I'm going to post next on the elog, together with the signals for the other degrees of freedom.

 Just to show that I'm confident I'm getting reasonable results, I'll post two PRC scans for different CARM. One set of plots is for the current 40m with -19.78 deg of SRM detuning phase, the other is for the Old Upgrade (9 Mhz vs the 11 currently planned) with no detuning phase.

I'm going to put together the results and get some conclusion about the 3f locking scheme for the current 40m and the upgrade.

Entry  Thu Jul 11 09:24:03 2013, Steve, Update, General, there should be nothing left on optable tops 

There are 4 oscilloscopes left on the AP optical table top.... It's only 25 lbs... Do not leave anything on the optical table tops!

    Reply  Tue Feb 16 09:13:39 2016, Steve, Update, General, there was a power outage & EQ 20160215_power_outage.png

Pasadena reported the Sunday night event as a power transient caused by the trip of a power transmission line. This affected the entire city. Once the loss was detected, the system automatically switches to an alternate source. It was about one second for the system to recover.

 

2W Innolight, both Lightwaves at the ends, PSL HEPA, Ref Cavity and 3 AC units  turned on.

The 40m vacuum did not trip. It is vacuum normal.

The Jetstore computer is indicating power failer.

 

EQ  3.9 4.9 km (3.1 mi) NNW of Big Bear City, CA34.3027, -116.863, 3km Feb 16 2016 09:24:21 UTC 37524376

 

Entry  Fri Sep 5 10:36:34 2008, steve, Update, PEM, thermostate setting changed 
Some one changed the thermostat (old control room ) setting behind 1Y6 from 73 to 79F
It should be in the elog.
The temp changed from freezing 20 to sunny 25 C
    Reply  Fri Sep 5 15:09:50 2008, rana, Update, PEM, thermostate setting changed 

Quote:
Some one changed the thermostat (old control room ) setting behind 1Y6 from 73 to 79F
It should be in the elog.

In fact, it is. I demand satisfaction for the injury to my elogging reputation!
    Reply  Mon Sep 8 13:47:35 2008, steve, Update, PEM, thermostate setting changed 

Quote:

Quote:
Some one changed the thermostat (old control room ) setting behind 1Y6 from 73 to 79F
It should be in the elog.

In fact, it is. I demand satisfaction for the injury to my elogging reputation!




Thermostate setting was changed from 79F to 77F behind 1Y6
Entry  Thu May 1 17:14:36 2014, steve, Update, PSL, thin window AR measured 

CVI broadband AR coating was measured at the PSL-enclosure table around 9-10am today. The 2W Innolight first PBS  S polarization beam was used with an other 1/2 wave plate and PBS.

W2-PW1-1004-C-633-1064-0   This 0.045" thick window has 0.7- 0.8 % reflected beam on each sides at 5 degrees of incidence, P polarization.

The specification is  R avg <0.5 % per surface at 0 degree

Rana wants The device would be useless with such a high R, but R 0.1% is OK so I will get V coating.

    Reply  Fri May 2 10:38:29 2014, steve, Update, PSL, thin window AR measured 

Quote:

CVI broadband AR coating was measured at the PSL-enclosure table around 9-10am today. The 2W Innolight first PBS  S polarization beam was used with an other 1/2 wave plate and PBS.

W2-PW1-1004-C-633-1064-0   This 0.045" thick window has 0.7- 0.8 % reflected beam on each sides at 5 degrees of incidence, P polarization.

The specification is  R avg <0.5 % per surface at 0 degree

Rana wants The device would be useless with such a high R, but R 0.1% is OK so I will get V coating.

 CVI V-AR coating at 1064 nm, 0 degree,  catalog item is R< 0.25% on each sides,

 R <0.1 % is custom at much higher prices.

This custom order should go with other  orders that has similar need.

From CVI: 5-6-2014

I checked the trace info on the W2-PW1-1004-C-633-1064-0, BBAR coated window that you received.  It is side 1, 0.42%R & side 2, 0.53%R @ 1064nm.  And with the shift, I’m not too surprised you ended up with 0.7%.  A V coat would start with <0.25% (and more typically coming in at ~0.1%) per surface.  As far as stock options, I have a 1”dia x 4mmT, fused silica window that is recorded as side 1, R=0.09 and Side 2, R=0.08% @ 1064.  Is this too think or will it work for you?

 

 

    Reply  Fri Sep 30 16:17:10 2011, kiwamu, Update, Green Locking, things to be done for the Yarm green lock 

Thank you for the summary.

I think now you are getting into a phase where you should start doing some quantitative and careful checks.

    1. Calculate how much light will be reflected from the cavity if the alignment is perfect.

    2. Investigate where those kHz oscillations are coming from.

    3. Estimate how much the 1.1 kHz corner frequency in LPF will reduce the phase margin around 10 kHz.

    4. Calculate the estimated amplitude of the PDH signal.

    5. Compute how big the gain of the PDH box should be.

Quote from #5585

 This is a kind of summary of what I have worked on this week. 

  • DC level of green PD when light resonates 75%
                    --> Not sure if this alignment is good enough
  • The PDH error signal was covered with oscillations of 3.3 kHz, 7.1 kHz and 35 kHz.
  • Designed and build a new LPF: second order, cut of frequency of 1.1 kHz (this is just the design value, haven't measured that so far)
  • Signal-to-noise ratio (SNR) could be improved to values between 7.8 and 11.1 (old SNR was 5 to 7)

Entry  Tue Oct 26 16:02:55 2010, yuta, HowTo, CDS, things to do after making a new Simulink model 

(Joe,Yuta)

Things to do after making a new Simulink model.

1. ssh c1sus, go to /opt/rtcds/caltech/c1/core/advLigoRTS/ and run
 bash ./makestuff.sh c1SYS

 makestuff.sh does;

  make uninstall-daq-$*
  make clean-$*
  make $*
  make install-$*
  make install-daq-$*
  make install-screens-$*
  sed -i 's/RO \(.*SW[12]R.*\)/\1/' /opt/rtcds/caltech/c1/target/$*/$*epics/autoBurt.req


 If you don't need to re-install DAQs or screens, just run line 2,3,4, and 7 and go to step #6.

2. ssh c1sus, go to /opt/rtcds/caltech/c1/scripts/ and run
 sudo ./startc1SYS

 For now, you have to put "1" in "BURT Restore" in GDS screens with in 5-10 secs.

3. Now the DAQ channel numbers are changed. So, go to /cvs/cds/rtcds/caltech/c1/chans/daq/ and run
 ./activateDAQ.py

 activateDAQ will activate the following DAQ channels for every optics with data rate 2048Hz;
  ULSEN_OUT
  URSEN_OUT
  LRSEN_OUT
  LLSEN_OUT
  SDSEN_OUT
  SUSPOS_IN1
  SUSPIT_IN1
  SUSYAW_IN1

4. Restart fb. See this wiki page.
 Basically you what have to do is kill and restart daqd in fb and restart mx_streams in c1sus.

5. DONE! Burt restore if you want.


6. If you don't need to re-install DAQs or screens;
  a. Go to /opt/rtcds/caltech/c1/target/c1SYS/c1SYSepics and run
    sudo rmmod c1SYSfe

  b. Go to /opt/rtcds/caltech/c1/target/c1SYS/bin/ and run
    sudo insmod c1SYSfe.ko

Entry  Mon Oct 31 15:58:25 2011, steve, Update, SUS, thinking of black glass baffles for 40m 03260901.PDF03260902.PDF

Shade 12 black glass-green lines: 1/8" thick,  6" wide  x 7 " high  mounted on angle bracket below.  Aperture 1" diameter. Let me know what do you think.

 

    Reply  Fri Jul 29 20:12:54 2016, gautam, Update, SUS, third time - no luck 

[lydia, gautam]

Summary: Third unsuccessful attempt at getting ETMX suspended. I think we should dial the torque wrench back down to 1.0 N m from 1.5 N m for tightening the primary clamp at the top of the SOS tower. No damage to magnets, standoff successfully retrieved (it is sitting in the steel bowl)

Details:

  • We burned through two sets of wires today.
  • First, the assembly Eric and I had put together last night failed when Eric tightened the wire clamp (no torque wrench was used I think?)
  • This afternoon, Lydia and I re-assembled the suspension once again. Standoff was successfully inserted, coarse pitch balancing was achieved relatively easily - we think that the coarse pitch balance can be achieved if the end of the wire standoff closer to the groove is ~0.5mm ahead (i.e. towards HR side) of the guide rod.
  • Checked leveling of scribe lines, gave an extra 0.25 turns on the winches in anticipation of the wire sagging
  • Inserted OSEMs just short of magnets, verified that they were approximately centered, if anything, slightly above center, again in anticipation of the wire sagging. 
  • After taking pictures, we went ahead and attempted to clamp the wire (ALL EARTHQUAKE STOPS WERE ENGAGED)
  • Eric commented that the clamp piece did not slide in smoothly on the dowels (indeed it does not come off very easily either, I have just left it on for now). I don't remeber it being so difficult prior to us sending it into the maching shop to get rid of the grooves made by the suspension wire the first time around. But with the torque wrench, the piece moved in relatively easily (we had sanded down rough edges prior to putting this piece onto the suspension earlier in the afternoon.
  • I could feel that the torque wrench coming up on its limit. But the wire snapped before the torque wrench clicked. As far as I am aware, there were no rough edges on the piece, but perhaps we missed a spot?
  • I took the opportunity to discharge the optic using ionized nitrogen at 40psi. After about 2-3 minutes of a steady stream, I verified that a piece of the suspension wire no longer gets attracted to the barrel, as was the case earlier today.

Unfortunately I don't know of a more deterministic way of deciding on a "safe" torque with which to tighten the bolts except by trial and error. It is also possible that the clamping piece is damaged in some way and is responsible for these breakages, but short of getting the edges chamfered, I am not sure what will help in this regard.


Unrelated to this work: earlier today before the first wire failure, while I was optimistic about doing fine pitch balancing and gluing the standoff, I set up an optical lever arm ~3m in length, with the beam from the HeNe on the clean bench at 5.5 in above the table, and parallel to it (verified using Iris close to the HeNe and at the end of the lever arm). I also set up the PZT buzzer - it needs a function generator as well for our application, so I brought one into the cleanroom from the lab, isopropanol wiped it. The procedure says apply 5Vrms triangular wave at 1000Hz, but our SR function generators can't put out such a large signal, the most they could manage was ~2Vrms (we have to be careful about applying an offset as well so as to not send any negative voltages to the PZT voltage unit's "External input". All the pieces we need for the fine pitch balancing should be in the cleanroom now.

    Reply  Mon Aug 1 14:09:20 2016, Steve, Update, SUS, third time - no luck 

Gautam and Steve,

The clamp's left side was jammed onto the left guide pin. It was installed slit facing left. Gautam had to use force to remove it. The clamp should move freely seating on the guide rods till torque aplied. Do not move on with the hanging of optic with a jammed clamp. Fix it.

Never use force as you are hanging - aligning optic. The clamp is in the shop for resurfacing and slit opening.

 

Entry  Wed Dec 30 09:57:53 2009, steve, Update, PSL, thirsty water chiller htemp60d.png

I added 600 cc of Arrowhead Distilled Water to the chiller.

60 days plot shows that about every ~ 10 days I have to add some.

Please check the water level yourself.

Entry  Thu Oct 18 15:03:14 2007, ajw, Routine, General, this is only a test DCreadoutNoise.pngdemo40m.png

    Reply  Wed Aug 10 07:59:33 2011, steve, Update, SUS, this is too dam nice 

Quote:

Suresh and I tweaked the OSEM angles in ETMX yesterday.  Last night the ETMs were left free swinging, and today I ran Rana's peakFit scripts on ETMX to check the input diagnolization:

ETMX.png

It's well inverted, but the matrix elements are not great:

       pit       yaw       pos       side      butt
UL    0.3466    0.4685    1.6092    0.3107    1.0428
UR    0.2630   -1.5315    1.7894   -0.0706   -1.1859
LR   -1.7370   -1.5681    0.3908   -0.0964    0.9392
LL   -1.6534    0.4319    0.2106    0.2849   -0.8320
SD    1.0834   -2.6676   -0.9920    1.0000   -0.1101

The magnets are all pretty well centered in the OSEMS, and we worked at rotating the OSEMS such that the bounce mode was minimized.

Rana and Koji are working on ETMY now.  Maybe they'll come up with a better procedure.

 

    Reply  Tue Oct 9 09:29:10 2012, Steve, Update, IOO, this is where we are 15days.png

Quote:

Quote:

 The new cold cathode gauge CC1 is in place. We were at atmosphere for 28 days ......more later

 

 cc1 = 2.3e-5 Torr at day 6 vacuum normal

 

Entry  Wed Dec 16 10:22:14 2015, Steve, Update, IOO, this morning PMClocked.png

c1sus and c1ioo were restarted. PMC locked.
 

Entry  Wed Apr 30 11:16:41 2014, Steve, Update, IOO, this typical morning 40days.png

c1sus and c1iscey were reset. The PMC needed to be locked. MC locked instantly.

The FSS ion pump power supply was turned on.

 

 

 

 

    Reply  Fri May 2 08:38:07 2014, Steve, Update, IOO, this typical morning 2dTrend.png

 

 c1sus needed reset.

Entry  Thu Aug 13 11:20:43 2009, janosch, HowTo, PEM, three-channel self-noise estimation 

There are two new Matlab files on the svn in /mDV/extra/C1. 'mycsd.m' is to calculate the cross-spectral density between two channels, 'csd_40T_40T_SS1.m' calls this function with the available seismic channels and derives a self-noise spectrum for the vertical axis using all three seismometers. The method requires that there are no correlations between two instruments only which is a bad idealization for certain frequencies if you have seismometers of totally different types.

'mycsd.m' uses the high-gain, low-resolution Nuttall window (built-in Matlab function 'nuttallwin.m'). High-gain windows are used for broad-band spectra like seismic spectra, but it should be exchanged by another window if you plan to look at small-bandwidth features like peaks.

Since the three-channel analysis does not require knowledge of response functions, it could be used to evaluate the performance of the adaptive filter. For example, if three channels responding to the same signal are available, then the ratio of any two csds corresponds to one of the relative transfer functions. You can then compare this function with the result produced by the adaptive filter.

    Reply  Mon Nov 10 19:39:40 2008, steve, Update, PEM, thump noise from particle counter partcfm.jpg
The particle counter is back on the IOOC location on a piece of FOAM
It needs this isolation, so when the pump is running, it's not shaking things.
The counter was counting for 6 sec and it was on holding for 20 mins.
Now I set the counter for 20 sec so it is easy to recognise it's signal and it holds for 2min only.
This will set the alarm handler in action.

Atm1: 40 mins plot
PEM-ACC_MC2_x,y,z up to 13 mins: pcounter at MC2 table, clamped, counting for 20s and holds for 2 mins
PEM-ACC_MC2_x,y,z from 13 to 26 mins: pcounter at MC2 table, not clamped, seated on 2" foam, counting 20s and holds for 2 mins
PEM-ACC_MC1_x,y,z from 26 to 40 mins: pcounter at MC1_IOOC location, not clamped, seated on 2" foam, counting 20s and holds for 2 mins

Rana won the bet



Quote:
I'll bet Steve a dollar that it is mechanical. The attached PDF compares all of the accelerometers from right now.

You can see that the RMS in MC2 is way bigger than MC1.

In the second PDF file you can see the time series. I had to play around a lot with DTT to get it to work. The DTT/Foton
combo on Allegra is not stable, so make sure your work early and often.

In the plots shown, I am bandpassing the time series from 600-700 Hz. I found that doing so allowed the burp in MC1 to remain
large and reduce the extraneous fuzz in MC2. As you can see there is no such noise in MC2.

So its a noise around 600-700 Hz that comes on quickly and then shuts off after several seconds. Its also very periodic in that
it comes on around every 20 minutes. Steve also tells me (although he refuses to put in the elog) that it started up around
August 20th (?). I feel like someone in the 40m lab ought to be able to guess what this is at this point.

Please convince Steve to elog his findings about when the noise started.

If one goes out there and stands next to it when the trend predicts its happening it becomes clear what it is.
    Reply  Tue Nov 12 23:05:06 2013, rana, Update, PEM, thump noise from particle counter 

Quote:
The particle counter is back on the IOOC location on a piece of FOAM
It needs this isolation, so when the pump is running, it's not shaking things.
The counter was counting for 6 sec and it was on holding for 20 mins.
Now I set the counter for 20 sec so it is easy to recognise it's signal and it holds for 2min only.
This will set the alarm handler in action.

Atm1: 40 mins plot
PEM-ACC_MC2_x,y,z up to 13 mins: pcounter at MC2 table, clamped, counting for 20s and holds for 2 mins
PEM-ACC_MC2_x,y,z from 13 to 26 mins: pcounter at MC2 table, not clamped, seated on 2" foam, counting 20s and holds for 2 mins
PEM-ACC_MC1_x,y,z from 26 to 40 mins: pcounter at MC1_IOOC location, not clamped, seated on 2" foam, counting 20s and holds for 2 mins

Rana won the bet

This noise source from 2008 is back. Somehow the particle counter snuck back up to the top of the BS chamber. Bad, noisy particle counter. Let's move it away from out sensitive optics and put it on the wall next to the router or maybe on some toolbox. Not on optics tables, chambers, or near them.
Entry  Fri Feb 27 13:49:19 2009, rob, Update, Locking, thurs night 

Could not get past arm power of ~11 or so.  I was suspicious of the transmon high-gain/low-gain PD handover, so I ran the matchTransMon scripts, but that did not help.  I also removed the line in the cm_step script that increased the CM gain by 18dB at an arm power of 4.  The gain of the CM servo will increase naturally as the power in the IFO builds up, so it may not be good to crank it right away.  I tried several other CM gains, and watched the DARM loop, but still could not get past an arm power of ~10-11.  I'm not sure what's wrong, but it may be that mysterious CM-servo/McWFS conspiracy, so we can try turning down the McWFS gain next time.

    Reply  Thu Aug 12 16:18:46 2010, steve, Update, Environment, tiles and adhesive removed P1060604.JPGP1060606.JPGP1060603.JPGP1060610.JPGDSC_2388.JPG

Quote:

I powered down 1Y1 and 1Y2 instrument racks of MC and RF-systems this morning.

Both racks, SP table, clean tools-parts boxes and MC2 area are also covered with plastics.

Bertin Bros. Construction, Inc is working on the floor preparation. Their head man is Robby Bertin, cell 626. 831.2264

Today's job:

remove tiles, clean off tile glue, drill for ribbed  steel bars, rough clean- surface for good bounding. paint floor with bounding agent

Tiles and adhesive removed. There were no dust storms created. Solvent paint- removal made the hole IFO -lab smell like the paint shop.

The south door is open with a fan blowing air inside. The north-west door is open through control room to outside to let air rinse the drying

paint-removal. Koji is  taking lunch break while test riding our new PSL table legs.

    Reply  Thu Aug 2 16:30:08 2018, Steve, Update, Treasure, time capsule location time_capsule.JPG

I 've just found this time capsule note from Nov. 26, 2000 by Kip Thorne:  LIGO will discover gravitational waves by Dec.31, 2007

Quote:

   Beautifully Done

   Chirp

  what is next?

Atm 3, Ron Drever could not celebrate with us because of health issues.

 

 

Entry  Fri Jul 6 08:38:04 2012, steve, Update, Computers, time out timingblanks.png

Why do we have these timing blanks?

ELOG V3.1.3-