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ID Date Author Type Category Subjectup
  11306   Tue May 19 00:19:23 2015 ranaUpdateGeneralsome status

There's a few hours so far after today's c1cal shut off that the summary page shows no dropouts. I'm not yet sure that this is related, but it seems like a clue.

  11315   Tue May 19 18:55:12 2015 rana, ericQUpdateGeneralsome status

After one day the pressures are east/west = 2200/450 PSI

Quote:

 

  1. New east pressure reading is 2500 PSI. Regulated N2 pressure is 68 PSI.

 

  11317   Wed May 20 03:08:27 2015 ranaUpdateGeneralsome status

I think that the real clue was that the dropouts are in some channels and not in others:

https://nodus.ligo.caltech.edu:30889/detcharsummary/day/20150519/psl/

As it turns out, the channel with no dropouts is the RAW PSL RMTEMP channel. All the others are the minute trends. So something is up with the trend making or the trend reading in the cluster.

Quote:

There's a few hours so far after today's c1cal shut off that the summary page shows no dropouts. I'm not yet sure that this is related, but it seems like a clue.

 

  11318   Wed May 20 11:41:59 2015 ericqUpdateGeneralsome status

West cyclinder is empty, east is at 2000 psi; regulated N2 pressure is 64psi. I'll replace the west one after the meeting.

  1222   Mon Jan 12 10:57:38 2009 robUpdateGeneralsome stuff

The AS beam was not hitting the AS166 diode, so I aligned the last little steering mirror and adjusted the phase for MICH locking.

I turned on the HV supplies for the OMC.

Then I realigned the beam onto the AS166 diode, since the steering mirrors came on when I turned on the HV supplies.

It took awhile to find the alignment of the beam into the OMC. Once that was done, the output beam alignment was set, so I aligned onto the AS166 diode a third time.

The bottom two Sorensens in the OMC voltage supply don't look right. They have stickers that say +-24V, but each is sitting at 17.5V and showing no current draw. What's going on here?
  15237   Mon Mar 2 16:14:47 2020 gautamUpdateCDSsome target directory cleanup

$TARGET_DIR = /cvs/cds/caltech/target

  • $TARGET_DIR/c1psl and $TARGET_DIR/c1iool0 moved to $TARGET_DIR/preAcromag_oldVME/
  • $TARGET_DIR/c1psl1 moved to $TARGET_DIR/c1psl 
  • $TARGET_DIR/c1psl/*.service and $TARGET_DIR/C1_PSL.cmd modified - i executed :%s/c1psl1/c1psl/g in vim.
  • $TARGET_DIR/preAcromag_oldVME/c1psl/autoBurt.req and $TARGET_DIR/preAcromag_oldVME/c1iool0/autoBurt.req catenated into $TARGET_DIR/c1psl/autoBurt.req. The first snapshot at 16:19 has been verified.

It remains to (Jon is taking care of these)

  • add a line to modbusIOC.service on the new c1psl machine that restores the latest burt snapshot on startup (this necessitated installation of a debian jessie libXp6 package on our debian buster machine because our shared EPICS is soooooooooooooo oooooooold)
  • change the hostname from c1psl1 to c1psl
  • update martian.hosts
  4458   Tue Mar 29 22:29:16 2011 kiwamuUpdateGeneralsome tasks tomorrow

 *  Temporary strain relief for the heliax cables on 1X2 (Steve)

 *  RF diagrams and check lists (Suresh)

      => In the lunch meeting we will discuss the details about what we will do for the RF installation.

 *  Electronics design and plan for Green locking (Aidan / Kiwamu)

      => In the lunch meeting we will discuss the details.

 *  LSC model (Koji)

 *  Video cable session (team)

 * LPF for the laser temperature control (Larisa)

  11071   Wed Feb 25 23:48:57 2015 ranaUpdateLSCsome thoughts
  • Comparing just the 2 cases with locking on 33, it seems that the 55 MHz gain has changed by 14 dB instead of the 10 dB that we expected. Is it that we need to measure the modulation drive change more carefully, or just that the PRMI was aligned differently?
  • The 165 signal changed by a factor of 60 (35 dB) which is more consistent with a ~12 dB change in Gamma2, so not so far off.
  • The fact that the whole sensing matrix increases in amplitude between 33 and 55 lock makes me think that either the alignment was very bad for the 33 lock, or that the 33 signals have a significant offset; if that's the case, then we should do as LLO and set the digital offsets in the 33 signals by locking first on 55.
  • How does the REFL33 demod phase change by 70 deg?
  5595   Sun Oct 2 02:33:32 2011 kiwamuUpdateLSCsomething funny with AS55

Just a quick report.

The AS55 signal contains more noise than the REFL signals.

Why ? Is this the reason of the instability in PRMI ?

outofloop.png

 I locked the Power-Precycled ITMY with REFL33.

As shown in the plot above, I compared the in-loop signal (REFL33) and out-of-loop signals (REFL11 and AS55).

All the signals are calibrated into the displacements of the PR-ITMY cavity by injecting a calibration peak at 283 Hz through the actuator of PRM.

AS55 (blue curve) showed a structure around 3 Hz and higher flat noise below 1 Hz.

Quote from #5582
I am suspecting that something funny (or stupid) is going on with the MICH control rather than the PRCL control.

 

  1170   Wed Dec 3 12:49:11 2008 jenneUpdateComputerssomething sketchy with NDS ... or something
Never mind...I had forgotten that you have to run mdv_config every time you open matlab, not just every time you boot a computer.

I am not able to get channels using get_data from the mDV toolbox on Allegra, Megatron or Rosalba.

The error I get while running the "hello_world" test program is:
hello_world
setting up configuration...
added paths for nds
added paths for qscan
couldn't add path for matapps_SDE
couldn't add path for matapps_path
couldn't add path for framecache
couldn't add path for ligotools_matlab
added paths for home_pwd
fetching channels for C...
Warning: get_channel_list() failed.
??? Error using ==> NDS_GetChannels
Failed to get channel list.

Error in ==> fetch_nds at 47
eval(['CONFIG.chl.' server ' = NDS_GetChannels(ab);']);

Error in ==> get_data at 100
out = fetch_nds(channels,dtype,start_time,duration);

Error in ==> hello_world at 6
aa = get_data('C1:LSC-DARM_ERR', 'raw', gps('now - 1 hour'), 32);
  4898   Tue Jun 28 14:21:41 2011 kiwamuUpdateIOOsomething wrong ? : Power incident on REFL11 and REFL55

The measured change in the REFL DC power with and without PRM aligned seems unacceptably small.  Something wrong ?

The difference in the power with and without PRM aligned should be more than a factor of 300.

         [difference in power] = [single bounce from PRM] / [two times of transmission through PRM ]

                                          = (1-T) / T^2 ~ 310,

where T is the transmissivity of PRM and T = 5.5% is assumed in the calculation.

Also the reflectivity of MICH is assumed to be 1 for simplicity.

Quote from #4894

We now have (with the PRM misaligned):

REFL11:  Power incident = 7.60 mW ;  DC out = 0.330 V  => efficiency = 0.87 A/W

REFL55:  Power incident = 23 mW ;  DC out = 0.850 V  => efficiency = 0.74 A/W

and with the PRM aligned::

REFL11:  DC out = 0.35 V  => 8 mW is incident

REFL55: DC out = 0.975 V  => 26 mW is incident

 

  4954   Thu Jul 7 14:27:16 2011 SureshUpdateIOOsomething wrong ? : Power incident on REFL11 and REFL55

Just tying up a loose end.  The next day Kiwamu and I checked to see what the trouble was.  We concluded that the PRM had not moved during my measurement though I had 'Misaligned' it from the medm screen.  So all the power levels measured here were with the PRM aligned.  The power level change was subsequently measured and e-logged

Quote:

The measured change in the REFL DC power with and without PRM aligned seems unacceptably small.  Something wrong ?

The difference in the power with and without PRM aligned should be more than a factor of 300.

         [difference in power] = [single bounce from PRM] / [two times of transmission through PRM ]

                                          = (1-T) / T^2 ~ 310,

where T is the transmissivity of PRM and T = 5.5% is assumed in the calculation.

Also the reflectivity of MICH is assumed to be 1 for simplicity.

Quote from #4894

We now have (with the PRM misaligned):

REFL11:  Power incident = 7.60 mW ;  DC out = 0.330 V  => efficiency = 0.87 A/W

REFL55:  Power incident = 23 mW ;  DC out = 0.850 V  => efficiency = 0.74 A/W

and with the PRM aligned::

REFL11:  DC out = 0.35 V  => 8 mW is incident

REFL55: DC out = 0.975 V  => 26 mW is incident

 

 

  5025   Mon Jul 25 00:35:44 2011 ranaUpdateSUSsomething wrong with ETMY LR sensor

a.png

Looks like either the LR OSEM is totally mis adjusted in its holder or the whitening eletronics are broken.

Also looks like the ETMY is just not damped at 1 Hz? How can this be?

I look at the SUS_SUMMARY screen which apparently only Steve and I look at:

bad.png

Looks like the suspensions have factor of 10-100 different gains. Why?

**  The ETMY just doesn't behave correctly when I bias it. Both pitch and yaw seem to make it do yaw. I leave this for Jamie to debug in the morning.

***  Also, the BIAS buttons are still broken - the HOPR/LOPR limits ought to be 5000 and the default slider increment be 100. Also the YAW button readback doesn't correctly show the state of the BIAS.

****  And.....we have also lost the DAQ channels that used to be associated with the _IN1 of the SUSPOS/PIT/YAW filter modules. Please put them back; our templates don't work without them.

  4269   Thu Feb 10 11:16:31 2011 steveUpdatePEMsouth arm AC turned on

The air condition was off for the south arm. I  turned it on.

  3513   Thu Sep 2 14:11:17 2010 steveSummaryPEMsouth end crane balancing is completed

The crane I -beam now leveled at all degrees of rotation.  The lower hinge was moved southward  about 1/4 of an inch.  Performance was tested at 2000 lbs

 

Atm1, work in progress

Atm2, load test at 1 Ton

Atm3, service report

  12187   Thu Jun 16 11:10:17 2016 SteveUpdateSUSspare ETMX optics preparation to be hanged

D Location

Number on

Drawing

 

Component

Name

 

 Baked Clean

 Pieces Needed

 

Pieces

In Stock

(on tower )

Notes
         
31,20,19,13 viton tips   not cut yet baked material in stock
30 6-32x0.75" stops 4 (4)  
29 steel music wire 0.017" not baked on roll  needs good wipes
28  1/4 "washer 4 (4)  
27 lock washer 4 50 install
26 Ag plated 1/4-20x1.25 4 (4)  
25 Ag plated1/4-25x.75 & not plated 20 (20)  
24 SS 4-40x.5 2 (2)  
23 SS 4-40x.38 4 (4)  
22 spring plunger 4+2 (4+2)  
         
         
18 magnets, 1.9mm od, length 3.2 mm 5 ~30 not coated, rusty

buy Ni coated ones for future use from www.electroenergy.com

 

17 guide rod, 0.635 mm od, 3.3 mm 3 6 Al
16 wire standoff, 1 mm od, 4.8 mm 2 2 Al and ruby (ruby groove not centered)
15 short OSEMs 5 6  
14 spare ETMX in 40m wiki 1 1  confirmed in cabinet
         
12 dumbbell standoff 5 6  
11 Al stiffening plate 1 (1)  
10 wire clamp B in sus block 2 (2)  
9 wire clamp A 1 (1)  
8-7 lower clamp for lifting optics 2 (2)  
6 upper clamp to hold down optic 1 (1)  
5-4 left-right side of tower  1 ea (1ea)  
3 tower base 1 (1)  
2 sus block 1 (1)  
1 lower and upper OSEM holders 1ea (1ea)  
         
48 sandind fixture for magnet&dumbbell      
45 magnet-dumbbell assemblly fixture 1 1  
43 guide-wirestandoff gluing fixture 1 1

Ok for larger RUBY,

unit is not in perfect condtition but usefull

 

         
  First contact   3-15-2013 purchase

Pick up  FC from Gary with purchasing date 7-7-2015

or later

  FCPEEK peeler ring disk for TM cleaning 10 front,10 back side  have sheets only 32&19mm ID punches ordered
  GordonBrush custom for LIGO optical cleaning ~5 1 (3/8wide nylonSS) more from Calum available
  EP30-2 epoxy have  have expiration date 9-24-2016

NOT finished, last edited 7-7

  13158   Wed Aug 2 09:40:55 2017 SteveUpdateElectronicsspare ILIGO electronics

Spare ILIGO electronics temporarly stored in the east arm. We need cabinet space.

  1387   Wed Mar 11 16:41:22 2009 steveUpdateMOPAspare NPRO power

The spare M126N-1064-700,  sn 5519 of Dec 2006 rebuilt  NPRO's power output

 measured   750mW at DC2.06A with Ohpir meter.

Alberto's controller  unit 125/126-OPN-PS,  sn516m was disconnected from lenght measurment NPRO on the AP table.

5519 NPRO  was clamp to the optical table  without heatsink and it was on for 15 minutes.

  12088   Mon Apr 25 11:07:06 2016 SteveUpdateSUSspare SOS tower

Earth quake stops need viton tips.

Wirestandoffs are still aluminum.

  12092   Wed Apr 27 09:45:56 2016 ranaUpdateSUSspare SOS tower

Bah, we need ruby slippers for all future suspensions. Prism with curved backside and smooth grooves.

No aluminum, no cry.

Quote:

Earth quake stops need viton tips.

Wirestandoffs are still aluminum.

 

  7071   Wed Aug 1 16:38:46 2012 steveUpdateSUSspare SRMU 03 optic moved

SOS optics prepared to be hanged are moved from the South Flow Bench to S15 Clean Cabinet.

SRMU 03 (1-25-2010) specification summery E080460-05-D,  older vintage SRM 01 and PRM 02 (need more specification)

There was one  NOT MARKED SOS with two broken magnets on its face. This is labeled ???

 

This was done to prepare clean space for TIP-TILT drive- test set up.

The existing cable from 1X5 can reach only to the south end:  from whitening filter to satelite amp.  This will be good for future test of suspensions.

We need to make new cable from 1 X 1 to the south end = 40m long

  7072   Wed Aug 1 17:04:22 2012 JenneUpdateSUSspare SRMU 03 optic moved

Quote:

There was one  NOT MARKED SOS with two broken magnets on its face. This is labeled ???

 While I'm not sure what specific optic this is, I think it's an older optic.  (a) All of the new optics we got from Ramin were enscribed with their #.  (b) This optic appears to have a short arrow scribe line (about the length of the guiderod), and then no scribe line (that I could see through the glass dish) on the other side.  The new optics all have a long arrow scribe line, ~1/2 the full width of the optic, and have clear scribe lines on the opposite side.

  7755   Tue Nov 27 17:45:42 2012 SteveUpdateGeneralspare optics of AP table moved to cabinet

Spare optics from the AP table were moved to glass cabinet in the east arm. I'm not sure this is the right place. We'll see what everybody thinks.

There were two UNMARKED optics. Shame on you! No pencil marks on the optics either. These optics were shipped to the FBI for finger tip analysis.

 

 

  632   Thu Jul 3 16:18:51 2008 robSummaryLockingspecgrams
I used ligoDV to make some spectrograms of DARM_ERR (1), QPDX (2), and QPDY (3). These show the massive instability from 30-40Hz growing in the XARM in the last two minutes of a reasonably high power lock (arm powers up to 30). It's strange that it only shows up in one arm.

CARM is on PO-DC, for both the MCL and the AO path.
DARM is on AS166Q.
  7517   Wed Oct 10 08:36:47 2012 SteveUpdateCOCspecial mirror mounts holder

Quote:

After looking at the in-vacuum layout I think we should make two changes during the next vent:

1) Reduce the number of mirrors between the FI and its camera. We install a large silvered mirror in the vacuum flange which holds the Faraday cam (in the inside of the viewport). That points directly at the input to the Faraday. We get to remove all of the steering mirror junk on the IO stack.

2) Take the Faraday output (IFO REFL) out onto the little table holding the BS and PRM Oplevs. We then relocate all 4 of the REFL RFPDs as well as the REFL OSA and the REFL camera onto this table. This will reduce the path length from the FI REFL port to the diodes and reduce the beam clutter on the AS table.

1)  Mirror mount holder for "large silvered mirror" inside of the 8" OD tube vacuum envelope.

  1684   Thu Jun 18 23:08:46 2009 robUpdateLockingspectrum

Here's a noise spectrum of the RSE interferometer, in anti-spring mode, with RF readout.  I'd say the calibration is "loose."

I used the Buonanno & Chen modification of the KLMTV IFO transfer functions to model the DARM opto-mechanical response.  I just guessed at the quadrature, and normalized the optical gain at the frequency of the calibration line used (927Hz, not visible on the plot).

  6183   Tue Jan 10 00:09:33 2012 kiwamuUpdateLSCspike hunting in REFL33

[John / Kiwamu]

 We tried to figure out what is causing spikes in the REFL33 signal, which is used to lock PRCL.

No useful information was obtained tonight and it is still under investigation.

 


(Background)

 One thing preventing us from doing smooth measurements of the noise budget and the sensing matrix is some sharp spikes in the LSC error signals.

For example when we lock PRMI with REFL33 and AS55 fedback to PRCL and MICH respectively, both the REFL33 and AS55 signals show some spikes in time series.

Those spikes then bring the noise spectra higher than how they should be.

So for the reason, taking the noise budget doesn't give us much information about the interferometer rather than there are spikes.

Also the sensing matrix measurement has been suffered from those spikes, which excite the impulse responses of the low pass filters in the LOCKIN detection systems a lot.

 

(What we did)

 We looked into the actual analog signals to see if there are indeed spikes or not before they are acquired to the ADCs.

But we didn't find any corresponding spikes in the signals that are after the mixers.

It maybe because the signals we looked into didn't have high enough SNR because they were coming out from the monitor lemo outputs on the demod boards.

 Then we thought the spikes are from the whitening circuits, due to some kind of saturation.

We decreased the gain of the whitening filters by a factor of 10, but it didn't help and the spikes were still there.

  6327   Mon Feb 27 19:04:13 2012 jamieUpdateCDSspontaneous timing glitch in c1lsc IO chassis?

For some reason there appears to have been a spontaneous timing glitch in the c1lsc IO chassis that caused all models running on c1lsc to loose timing sync with the framebuilder.  All the models were reporting "0x4000" ("Timing mismatch between DAQ and FE application") in the DAQ status indicator.  Looking in the front end logs and dmesg on the c1lsc front end machine I could see no obvious indication why this would have happened.  The timing seemed to be hooked up fine, and the indicator lights on the various timing cards were nominal.

I restarted all the models on c1lsc, including and most importantly the c1x04 IOP, and things came back fine.  Below is the restart procedure I used.  Note I killed all the control models first, since the IOP can't be restarted if they're still running.  I then restarted the IOP, followed by all the other control models.

controls@c1lsc ~ 0$ for m in lsc ass oaf; do /opt/rtcds/caltech/c1/scripts/killc1${m}; done
controls@c1lsc ~ 0$ /opt/rtcds/caltech/c1/scripts/startc1x04
c1x04epics C1 IOC Server started
 * Stopping IOP awgtpman ...                                                                      [ ok ]
controls@c1lsc ~ 0$ for m in lsc ass oaf; do /opt/rtcds/caltech/c1/scripts/startc1${m}; done
c1lscepics: no process found
ERROR: Module c1lscfe does not exist in /proc/modules
c1lscepics C1 IOC Server started
 * WARNING:  awgtpman_c1lsc has not yet been started.
c1assepics: no process found
ERROR: Module c1assfe does not exist in /proc/modules
c1assepics C1 IOC Server started
 * WARNING:  awgtpman_c1ass has not yet been started.
c1oafepics: no process found
ERROR: Module c1oaffe does not exist in /proc/modules
c1oafepics C1 IOC Server started
 * WARNING:  awgtpman_c1oaf has not yet been started.
controls@c1lsc ~ 0$ 
  5371   Fri Sep 9 16:16:59 2011 kiwamuUpdateIOOspot positions on MC mirrors (in-vac)

The spot positions on the MC mirrors were measured in the vacuum condition.

The obtained spot positions are quite bad and roughly at 2-3 mm level. We have to realign the beam axis and the MC mirrors.

 

    Feb 26 2011      May 08 2011 Aug 2 2011  Aug 10 2011 (in air) Aug 14 2011 (in air)

Aug 23 2011 (in air)

[NEW]  Sep 9 2011
MC1 pit [mm]   1.6   1.9  1.93 -0.858 -0.2 0.1354  -1.55
MC2 pit [mm]   6.4   9.0 9.03 -0.844 -0.8 -0.2522  -2.28
MC3 pit [mm]   1.4   2.0 2.01 -1.03 -0.1 -0.1383  -1.8
MC1 yaw [mm]   -1.5   -1.7 -1.72 -0.847 -1.1 -1.0893  -0.02
MC2 yaw [mm]   1.0   0.2 0.178 0.582 0.6 0.7122  3.52
MC3 yaw [mm]   -1.3   -1.9 -1.87 -1.06 -1.1 -1.5587  -2.145

 

  5373   Fri Sep 9 20:52:59 2011 kiwamuUpdateIOOspot positions on MC mirrors (in-vac)

The spot positions on the MC mirrors were readjusted.

All the amount of the off-center became smaller than 2 mm, which meet requirements of the beam clearance on the Faraday.

 

    Feb 26 2011      May 08 2011 Aug 2 2011  Aug 10 2011 (in air) Aug 14 2011 (in air)

Aug 23 2011 (in air)

 Sep 9 2011 [NEW] Sep 9 2011
MC1 pit [mm]   1.6   1.9  1.93 -0.858 -0.2 0.1354  -1.55  0.22
MC2 pit [mm]   6.4   9.0 9.03 -0.844 -0.8 -0.2522  -2.28  -0.34
MC3 pit [mm]   1.4   2.0 2.01 -1.03 -0.1 -0.1383  -1.8 -0.21
MC1 yaw [mm]   -1.5   -1.7 -1.72 -0.847 -1.1 -1.0893  -0.02 -1.15
MC2 yaw [mm]   1.0   0.2 0.178 0.582 0.6 0.7122  3.52 0.07
MC3 yaw [mm]   -1.3   -1.9 -1.87 -1.06 -1.1 -1.5587  -2.145 -1.07

 

 In order to improve the MC1-YAW and MC3-YAW spot positions, the angle of the incident beam has to be shifted by approximately 1/100 rad.

However it turned out to be very difficult to introduce such amount of angle only with the steering mirrors on the PSL table since we have to keep the same translation while changing the angle.

 

Quote from #5371

The obtained spot positions are quite bad and roughly at 2-3 mm level. We have to realign the beam axis and the MC mirrors.

 

  529   Wed Jun 11 11:45:25 2008 steveUpdatePSLss trap works
The trap works well at 3 W level. No back reflected beam coming out of the trap on low power
sensing card level. The back scattering was not measured. The trap is insensitive to small pointing variations.
The SS surface did not show any visible degradation after 16 hrs of 3w exposure at elliptical beam size 4x8 mm

It is ready to be placed into the 35 W beam.
  1372   Mon Mar 9 10:59:05 2009 AlanOmnistructureComputersssh agent on fb40m restarted for backup

After the boot-fest, the nightly backup to Powell-Booth failed, and an automatic email got sent to me. I restarted the ssh agent, following the instructions in /cvs/cds/caltech/scripts/backup/000README.txt .

  2081   Mon Oct 12 17:14:39 2009 robUpdateLockingstability

Last night, 2+ hour lock, probably broken by me driving too hard (DARM_EXC).

  11708   Fri Oct 23 09:55:50 2015 SteveUpdateLSCstable days
  8212   Sat Mar 2 05:53:15 2013 yutaUpdateLSCstable lock of PRMI

I tuned alignment, gains and filters to achieve stable lock of PRMI.
It now locks quite stably with UGF of ~100 Hz. Measured power recycling gain at maximum is ~ 25.

Locking details:
  == PRMI carrier ==
  MICH: AS55_Q_ERR, AS55_PHASE_R = -12 deg,  MICH_GAIN = -1, feedback to ITMX(-1),ITMY(+1)
  PRCL: REFL55_I_ERR, REFL55_PHASE_R = 70 deg, PRCL_GAIN = 0.3, feedback to PRM

  MICH servo is always on. PRCL loop turns on by trigger using POP DC. Boost filters and resonant gains turn on by triggers using POP DC.
  Gain normalization was not used.


Openloop transferfunctions:

  MICH: UGF ~90 Hz, phase margin ~40 deg
  PRCL: UGF ~100 Hz, phase margin ~50 deg (cf. Fitted gain was same as half-PRC: elog #8053)
LSCMICHOLTF_PRMI.png    LSCPRCLOLTF_PRMI.png



Power recycling gain:

  POP DC when unlocked is 6, when locked is 2200-2500, and when dark is 0. So, power recycling gain is ~ 22 to 25. Value without any loss in PRMI is 45 (elog #6947). Alignment was pretty critical to achieve this recycling gain and stable lock.
  There was oscillation at 630 Hz when locked, which is similar to the one we saw in POX11 (elog #8203).


Youtube:





AS(top left), POP(top right), REFL(bottom left), and ETMYT(bottom right). ETMY was mis-aligned, but you can see the beam at ETMYT after PRMI was carrier locked.



MICH/PRCL coupling:

  I measured "sensing matrix" of PRMI by tickling PRM/ITMs/BS at 8.5 Hz and measuring 8.5 Hz peak height of AS55_Q, REFL55_I spectra during PRMI lock (attached is an example measurement of PRM). Below table is the result. AS55_Q has ~5% of sensitivity to PRCL compared with MICH. Also, BS introduces REFL55_I signal considerably. And also, there seems to be an imbalance in actuation efficiency between ITMX and ITMY.

actuation AS55_Q_ERR   REFL55_I_ERR
ITMX      +11.4        +0.80
ITMY      +33.0        +1.06
BS        +50.8        +1.90
PRM       - 0.7        +1.05



AS clipping:
  AS was clipped inside the vaccuum the other day(elog #8198). So, I tried to avoid AS clipping by aligning BS this morning. But it turned out that avoiding AS clipping by BS makes ITMX beam centering worse. Maybe we should center the beam on Yarm first next week.


Next:
 - calculate expected PRMI recycling gain with loss, PR2 filpped
 - beam centering on the arms
    - IPANG, IPPOS, Y green, X green
    - PRMI g-factor measurement

  8213   Sat Mar 2 14:52:02 2013 ranaUpdateLSCstable lock of PRMI

  Whereas the sensing matrix coefficients for ITMX/ITMY in REFL_I indicate an actuation imbalance, the disparity in the ITMX/ITMY to AS_Q elements does not. However, they do indicate why there is a PRM to AS_Q coupling at all.

I would recommend setting up the triggering so that the REFL & AS whitening is turned on AFTER lock acquisition and using a frequency of ~100-300 Hz for the sensing matrix measurement to fix these issues.

  5882   Sat Nov 12 02:46:13 2011 DenUpdateAdaptive Filteringstacks and ground

We measured the coherence between the seismometer near the MC2 stack and accelerometers on the vacuum tank where MC2 is. Because accelerometers produce small signals at low frequencies, which are comparable with adc noise, we  amplified the accelerometer signal by a factor of 20. We could not do it more because though adc has 40 V range, the black box that follows the channel sockets can transmit only 2.5 V max amplitude signal. Probably, this was done because old adc accepted 2 V max amplitude.

ground_stack.jpg

ground_stack_coherence.jpg


We were able to found some coherence at 0.1-1 Hz though the accelerometer signal is rather noisy. So to consider stack as a noise source is still possible. This measurement should be better done with two seismometers, one on the floor, the other on the stack. From the figure we can also see that tilt affects the x and y seismometer signals from 0.1 Hz. Green line (z-component) is much lower that red and blue lines (x and y). Tilt affects on horisontal axes of the seismometer much more than on vertical.

What we also think about is that at low frequencies mirrors start to move approximately the same and seismometers can help us to figure out small reletive displacement of the mirrors which form the MC length. We can estimate the critical frequency by presenting the ground motion as interference of surface waves with different velocities and amplitudes. For only 1 wave we have for the relation of MC length to the seismometer read out  ~sin (2*pi*f/v*L). f - frequency of the wave, v -speed, L - length between the mirrors. We can see that below 1 Hz we have ~sin (f/2). At this point seismometer signal could lose coherence with MC length signal. We could try to subtract seismometer signals from corresponding axes, but gur1 and sts1 has different calibrations. Moreover, the noise floor of the seismometers might not allow us to measure the differential signal. We'll try to simulate this scenario and find seismometer calibration or measure it. We are basicly interested only in the ratio of calibraion fucntions of 2 seismometers.

  3704   Wed Oct 13 09:35:41 2010 ranaUpdateelogstart script edited

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

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

  4311   Thu Feb 17 11:20:04 2011 josephbUpdateCDSstart scripts no longer need sudo

I've modified the rc.local file to run the IOC codes as controls, which means they no longer write root permission log files on startup.

The awgtpman, which was the other permission issue with the start scripts, is started by a run script now.  This new version seems to be content to keep the permissions of the current log file, which is set to controls.

This should prevent the issue of sudo wiping your path environment variable for just that command. (Try "sudo which burtwb" versus "which burtwb" for example).  This apparently a security feature of sudo.

If you should happen to use sudo to run a start script, the easiest solution to fix the permissions is just got to the target directory (type "target") and run "sudo chown controls:controls -R *" on one of the workstations (the front ends don't handle the groups properly at the moment).

This should allow the scripts to properly use burtrb and burtwb to write and backup burt files.

  4935   Sun Jul 3 21:18:06 2011 ranaUpdateComputer Scripts / ProgramsstatScreen scripts dead since Feb 4 / now revived

This CSHRC mangling on Feb 4 did more than re-arrange FB binaries.

It broke the path to MEDM for the 32-bit machines in the lab (e.g. mafalda) and stopped the MEDM snapshots from being posted onto our MEDM Status Web Page.

This is because, in addition to the paths mentioned in the above elog, the paths to the EPICS directories were also commented out. I've re-inserted them into our

.cshrc file in the 32-bit section; the statScreen CRON that Yoichi set up is now back in business.

 

* for some reason, the 'cronjob.sh' script is wiping out its own log file. It would be great if someone who understands stderr output re-direction can fix it so that the log-file from each run is retained until the next time cron runs.

  7497   Sun Oct 7 23:39:10 2012 DenUpdateModern Controlstate estimation

I've applied online state estimation technique using Kalman filter to LQG controller. It helps to estimate states that we do not measure. I've considered MC2 local damping, we measure position and want to estimate velocity that we need for control. We can either differentiate the signal or apply state estimation to avoid huge noise injection at high frequencies. In state estimation we need to know noise covariance, I've assumed that LID sensor noise is 0.1 nm. Though covariance can be calculated better.

In the time-domain figure C1:SUS-MC2_SUSPOS_IN1 = MC2 postion, C1:SUS-MC2_SUSPOS_OUT = MC2 velocity obtained by differentiation, 2 other channels are estimations of position and velocity.

  7499   Mon Oct 8 09:51:30 2012 ranaUpdateModern Controlstate estimation

 

 I guess that the estimated state has the same low pass filter, effectively, that we use to low pass the feedback signal in SUSPOS. I wonder if there is an advantage to the state estimation or not. Doesn't the algorithm also need to know about the expected seismic noise transmission from the ground to the optic?

  7503   Mon Oct 8 12:34:52 2012 DenUpdateModern Controlstate estimation

Quote:

 

 I guess that the estimated state has the same low pass filter, effectively, that we use to low pass the feedback signal in SUSPOS. I wonder if there is an advantage to the state estimation or not. Doesn't the algorithm also need to know about the expected seismic noise transmission from the ground to the optic?

 I think state estimation and optimal control are two different techniques that are often used together. Sometimes (as for pendulum) we can use LQG without state estimation as we need only position and velocity. But for more complex systems (like quad suspension) the states of all 4 masses can be reconstructed in some optimal way using information from only one of them if the dynamics is sufficiently well known. When current system states are measured/estimated we can apply control where all our filters are hidden.

 The algorithm needs to know about expected seismic noise transmission from the ground to the optic, but it might be not very precise. I gave it some rough estimate, there are better ways to do it. I think that we'll understand whether we need state estimation or not when we'll move to more complex systems. Brett uses a similar approach for his modal control. Interesting if these methods + seismometer readings will be able to say if one of your sensors is noisier then others.

 

 

 

 

 

 

 

 

 

  6492   Fri Apr 6 10:31:07 2012 DenUpdateAdaptive Filteringstatic and adaptive

I've run static and adaptive filters simultaneously. AA32 filters rotate the phase of the witness signals GUR1X and GUR1Y and now the performance of the static filter is worse. Next time I'll recalculate Wiener filter coefficients taking this into account. But still 2 filters together can deal with a stack better.

static_oaf.pdf

  6493   Fri Apr 6 11:14:34 2012 JenneUpdateAdaptive Filteringstatic and adaptive

Quote:

I've run static and adaptive filters simultaneously. AA32 filters rotate the phase of the witness signals GUR1X and GUR1Y and now the performance of the static filter is worse. Next time I'll recalculate Wiener filter coefficients taking this into account. But still 2 filters together can deal with a stack better.

static_oaf.pdf

 This is super awesome!  I'm totally excited!!

  6491   Fri Apr 6 09:57:24 2012 DenUpdateAdaptive Filteringstatic starts to work

I made static filter to work to evaluate the actuator TF.. Here is the result of static filtering:

static1-crop.pdf

 What I did:

 I did offline simulation of the MC_F Wiener filtering using 2 witness signals - GUR1X and GUR1Y. I've downsampled the data from 2048 to 128 Hz and applied the Wiener filter with 10000 for each witness channel:

wiener_filtering.pngcoeffs.png

                                            Result of the filtering                                                                                     Filter coefficients for gur1x and then gur1y

xTF.pngyTF.png

                                         Gur1x -> MC_F transfer function                                                                          Gur1y -> MC_F transfer function

Then using vectfit I approximated obtained transfer functions in the region 0.5 - 20 Hz. I used a window function and then weights to get a more precise result in this range using only 8 poles and zeros.

xfitting.pngyfitting.png

I obtained the zpk-model for each witness channel and entered it into the FOTON splitting it into 2 parts before that because FOTON does not like too long filters. These zpk-models are at the C1:OAF-STATIC_STATMTX_8_8 and C1:OAF-STATIC_STATMTX_8_9 filter banks.

GUR1X:

z =

  7.527339430029315 +31.603999069997801i
  7.527339430029230 -31.603999069997823i
 27.897703898191267 + 0.000000000000071i
 -6.437806394766186 + 9.893955654289517i
 -6.437806394766159 - 9.893955654289510i
  1.114401249545640 + 5.479278396987240i
  0.176877296954015 + 0.000000000000006i
  1.114401249545616 - 5.479278396987245i


p =

 -0.407251778925379 + 6.263247012022007i
 -0.407251778925379 - 6.263247012022007i
 -0.230672968859081 + 6.846868757063707i
 -0.230672968859081 - 6.846868757063707i
 -2.871419857491615 +13.707864827517826i
 -2.871419857491615 -13.707864827517826i
 -2.134260618362721 +18.319129999777648i
 -2.134260618362721 -18.319129999777648i


k =

     4.113285626223658e-04

GUR1Y

z =

 17.961416874092624 +13.631821252434328i
 17.961416874092642 -13.631821252434353i
 -8.788634771726304 + 7.653357335975781i
 -8.788634771726285 - 7.653357335975777i
 -0.037906973323273 + 5.133348020858679i
 -0.164348392996182 + 3.588803405511463i
 -0.164348392996187 - 3.588803405511474i
 -0.037906973323277 - 5.133348020858679i


p =

 -0.027577318242359 + 5.174655410828068i
 -0.027577318242359 - 5.174655410828068i
 -0.500384298611703 + 6.310552036591990i
 -0.500384298611703 - 6.310552036591990i
 -0.237055716999485 + 6.881204941979009i
 -0.237055716999485 - 6.881204941979009i
 -1.408223271160550 +14.874570175309771i
 -1.408223271160550 -14.874570175309771i


k =

    -2.723835471763049e-04

 Then I approximated the reversed actuator TF  and placed it to the C1:OAF-SUS_MC2_OUT filter bank. The gain to the static filter output is -1.

P.S. Also the static matrix was filled with 1 for some reason. Here is the script to fix it if if will be bad again

for i in {1..8}
do
    for j in {1..28}
    do
        element="C1:OAF-STATIC_STATMTX_"$i"_"$j"_GAIN"
        ezcawrite $element 0
    done
done

 

 

  6296   Sat Feb 18 17:01:26 2012 DenUpdateAdaptive Filteringstatic variables

In order to prevent different DOF from redetermining static variables in the adaptive code, I've created a separate code for each DOF with the name ADAPT_XFCODE_{$DOF}.c

I've provided the links for these files in the c1oaf.mdl, compiled and run it. Now there are no conflicts between DOFs.

  3999   Tue Nov 30 16:02:18 2010 josephbUpdateCDSstatus

Issues:

1) Turns out the /opt/rtcds/caltech/c1/target/gds/param/testpoint.par file had been emptied or deleted at one point, and the only entry in it was c1pem.  This had been causing us a lack of test points for the last few days.  It is unclear when or how this happened.  The file has been fixed to include all the front end models again.  (Fixed)

2) Alex and I worked on tracking down why there's a GPS difference between the front ends and the frame builder, which is why we see a 0x4000 error on all the front end GDS screens. This involved several rebuilds of the front end codes and reboots of the machines involved. (Broken)

3) Still working on understanding why the RFM communication, which I think is related to the timing issues we're seeing.  I know the data is being transferred on the card, but it seems to being rejected after being red in, suggesting a time stamp mismatch. (Broken)

4) The c1iscex binary output card still doesn't work.  (Broken)

Plan:

Alex and I will be working on the above issues tomorrow morning.

Status:

Currently, the c1ioo, c1sus and c1iscex computers are running with their front ends. They all still have 0x4000 error.  However, you can still look at channels on dataviewer for example.  However, there's a possibility of inconsistent timing between computer (although all models on a single computer will be in sync).

All the front ends where burt restorted to 07:07 this morning.  I spot checked several optic filter banks and they look to have been turned on.

  3681   Fri Oct 8 17:35:24 2010 josephbUpdateCDSstatus of c1ioo, c1sus and rfm

RFM is still not working.  I can see data on a filter just before it reaches the RFM sending code, but I see only zeros on the receiving side.

c1sus machine and c1x02, c1sus, c1mcs, c1rms are running.  At the moment, the c1mcs model is running at about 42 microseconds for USR time and 56 microseconds for CPU MAX, which is close to the 61 microsecond limit.  This is with MC filters on.  So far it has not been late, but its not clear to me if its going to stay that way.  So far I haven't been able to isolate why it sometimes slows down after a few minutes.  Also, it was running faster earlier in the day (around 30-ish microseconds) and I believe it has slowed down slightly in the last hour or two.

c1ioo machine and c1x03, c1ioo are running. However its not doing very much good as I can't get any data transferred from it to any of the optic suspensions. I need to spend some more time debugging this and then grab Alex I think.

  1302   Fri Feb 13 16:30:49 2009 steveConfigurationGeneralstatus quo is disturbed

I have been getting ready for the annual safety inspection in the past 2-3 days.

Meaning cleaning up and disturbing the status quo on the floor  mostly under the optical tables and their surroundings.
For example: pd power supplies, He/Ne laser ps. and their positions.
BNC cables and ac power line positions can be different.
The new rule: no electronic equipment on the floor.
 
All electronic equipment were moved-placed into a plastic dish or tray.
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