Displaying reports 55861-55880 of 83105.Go to page Start 2790 2791 2792 2793 2794 2795 2796 2797 2798 End
Reports until 11:32, Tuesday 28 June 2016
H1 ISC
peter.fritschel@LIGO.ORG - posted 11:32, Tuesday 28 June 2016 - last comment - 11:47, Wednesday 29 June 2016(28009)
Monitoring PI Modes with the OMC DCPDs

The OMC DCPDs have proven to be useful for monitoring the test mass acoustic modes around 15 kHz, but there is a lot of low-pass filtering in the readout chain that render them less useful for monitoring higher frequency acoustic modes. This is now being changed with modifications to the electronics that will provide separate, faster channels for PI monitoring:

The attached plot shows the magnitude response of the low-pass filtering in the previous case, and with the poles removed from the whitening and AA channels. It is no wonder that no PI modes have been seen above the 15-16 kHz grouping, as there is 40 dB of relative attenuation already at 25 kHz.

I also attach a 1kHz - 10 MHz transfer function of the in-vacuum DCPD readout that Koji measured at Caltech:

https://nodus.ligo.caltech.edu:8081/OMC_Lab/235

Images attached to this report
Comments related to this report
peter.fritschel@LIGO.ORG - 11:47, Wednesday 29 June 2016 (28057)

Here are the transfer functions with the AA notch included. I had forgotten that the notch is a passive twin-T type, which by design has a Q = 1/4, so it is quite wide and should be taken into account. In future the AA notches should also be removed.

Images attached to this comment
H1 PEM (PEM)
vincent.roma@LIGO.ORG - posted 11:11, Tuesday 28 June 2016 (28008)
Removed Sensors from Infrasound Mics for Upgrades

The infrasound mics have already been upgraded at LLO but today I removed the sensors at LHO.  I removed the sensors from the microphones in the CS, at EX, and at EY.  This meant unscrewing the bottom of the instrument box and pulling out some of the equipment.  As far as I could tell everything went as planned and the equipment will now be sent away for upgrades.

H1 CDS
james.batch@LIGO.ORG - posted 10:54, Tuesday 28 June 2016 (28007)
Replacement of 18bit DAC successful for h1susb123, h1sush2a
WP 5954

All of the 18bit DAC cards in h1susb123 and h1sush2a now successfully pass the autocal on both power up and restart of the IOP models.  Results shown below:

h1susb123 - power up
[   61.694760] h1iopsusb123: DAC AUTOCAL SUCCESS in 5344 milliseconds
[   67.057232] h1iopsusb123: DAC AUTOCAL SUCCESS in 5340 milliseconds
[   72.850938] h1iopsusb123: DAC AUTOCAL SUCCESS in 5344 milliseconds
[   78.213461] h1iopsusb123: DAC AUTOCAL SUCCESS in 5345 milliseconds
[   85.247010] h1iopsusb123: DAC AUTOCAL SUCCESS in 6571 milliseconds
[   90.610149] h1iopsusb123: DAC AUTOCAL SUCCESS in 5344 milliseconds
[   95.973497] h1iopsusb123: DAC AUTOCAL SUCCESS in 5345 milliseconds
[  101.336018] h1iopsusb123: DAC AUTOCAL SUCCESS in 5340 milliseconds
h1susb123 - IOP model restart
[  911.921930] h1iopsusb123: DAC AUTOCAL SUCCESS in 5344 milliseconds
[  917.282286] h1iopsusb123: DAC AUTOCAL SUCCESS in 5345 milliseconds
[  923.070351] h1iopsusb123: DAC AUTOCAL SUCCESS in 5341 milliseconds
[  928.430617] h1iopsusb123: DAC AUTOCAL SUCCESS in 5344 milliseconds
[  935.453979] h1iopsusb123: DAC AUTOCAL SUCCESS in 6576 milliseconds
[  940.814416] h1iopsusb123: DAC AUTOCAL SUCCESS in 5345 milliseconds
[  946.174750] h1iopsusb123: DAC AUTOCAL SUCCESS in 5345 milliseconds
[  951.535191] h1iopsusb123: DAC AUTOCAL SUCCESS in 5341 milliseconds

h1sush2a - power up
[   48.086815] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds
[   53.450158] h1iopsush2a: DAC AUTOCAL SUCCESS in 5345 milliseconds
[   60.479701] h1iopsush2a: DAC AUTOCAL SUCCESS in 6576 milliseconds
[   65.843077] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds
[   71.640028] h1iopsush2a: DAC AUTOCAL SUCCESS in 5345 milliseconds
[   77.001396] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds
[   82.364713] h1iopsush2a: DAC AUTOCAL SUCCESS in 5345 milliseconds
h1sush2a - IOP model restart
[ 1252.909059] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds
[ 1258.269410] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds
[ 1265.292831] h1iopsush2a: DAC AUTOCAL SUCCESS in 6572 milliseconds
[ 1270.653176] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds
[ 1276.441059] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds
[ 1281.801414] h1iopsush2a: DAC AUTOCAL SUCCESS in 5344 milliseconds
[ 1287.161817] h1iopsush2a: DAC AUTOCAL SUCCESS in 5345 milliseconds
H1 AOS
corey.gray@LIGO.ORG - posted 10:35, Tuesday 28 June 2016 - last comment - 10:52, Tuesday 28 June 2016(28005)
Test Mass & HAM Oplevs vs Locklosses

Last week, Rana was inquiring about how locklosses affect oplev sums. 

Took a random sample of locklosses from O1 and came up with fairly consistent results for after a lockloss, so here's the nitty gritty:

Attached is an example of a lockloss from Nov.

Non-image files attached to this report
Comments related to this report
keita.kawabe@LIGO.ORG - 10:52, Tuesday 28 June 2016 (28006)

There's a DCC document and even a tool to look at these things.

https://dcc.ligo.org/LIGO-T1600085

H1 PSL (PSL)
peter.king@LIGO.ORG - posted 09:00, Tuesday 28 June 2016 - last comment - 15:15, Tuesday 28 June 2016(28003)
PSL cooling
We adjusted the pressure on the pwrmtr water circuit from its nominal 5 bar to 4.5 bar.  The flow rate to the
laser heads decreased somewhat.  Put the pressure back to ~5 bar to set the flow rate in the circuit to be
over 1.25 l/min.

    In doing so, the other flow rates seemed to behave as expected.  We will monitoring the flow rates and
pressures over the the next few days to see if anything settles out/down.






Jeff, Peter
Comments related to this report
sheila.dwyer@LIGO.ORG - 15:15, Tuesday 28 June 2016 (28020)

Have been monitoring the PSL chiller trends during the day. The attached plot is for an 8 hour period. The spikes at 06:50 (PT) are when Peter and I varied the pressures regulators. The pressures and flows have flattened out, which is good. The head flows have also flattened out, which is also good. The head temperatures have been moving around a bit (by 0.1 degree). It appears that varying these pressures regulators may have stabilized the pressure and flows. Will check again in the morning to see if these trends hold.   

Images attached to this comment
H1 PSL (PSL)
peter.king@LIGO.ORG - posted 08:56, Tuesday 28 June 2016 (28002)
DC block
Measured ~18 mV, 20 ohms between the table surface and the chassis of the ISS AOM.  Installed DC block.
Measured the same afterwards, so I removed the DC block.

This clearly does not work as well as the one on the FSS AOM (for whatever reason).
LHO VE
john.worden@LIGO.ORG - posted 08:53, Tuesday 28 June 2016 - last comment - 13:33, Tuesday 28 June 2016(28001)
New PID control at End Y CP7

I have set the level setpoint to 90% to exercise the new PID control.

Comments related to this report
john.worden@LIGO.ORG - 12:06, Tuesday 28 June 2016 (28011)

Here is the response.

Looks good Patrick!

Images attached to this comment
john.worden@LIGO.ORG - 13:33, Tuesday 28 June 2016 (28015)

Restored setpoint to 92%.

LHO VE
kyle.ryan@LIGO.ORG - posted 07:03, Tuesday 28 June 2016 - last comment - 08:17, Tuesday 28 June 2016(27998)
CP5 level control amis
Found that the PI output for CP5 was 0% even though the pump level is at 83% -> I switched CP5 to manual control with LLCV %open of 90% -> The other vacuum group members have been experimenting with CP5 of late so I'll "stay out of the kitchen" and let them continue/investigate.
Comments related to this report
kyle.ryan@LIGO.ORG - 07:35, Tuesday 28 June 2016 (27999)
Changing to 35% while transfer line cools -> Need to do stuff in other room and will monitor exhaust pressure sporadically. 
john.worden@LIGO.ORG - 08:17, Tuesday 28 June 2016 (28000)

Back to PID at  08:00 as the PID output had risen to 90%.

H1 ISC (ISC)
lisa.barsotti@LIGO.ORG - posted 00:08, Tuesday 28 June 2016 - last comment - 09:12, Tuesday 28 June 2016(27990)
40W towards low noise, more PI damping tests
Jenne, Carl, Sheila, TJ, Stefan, Lisa

We have a quite reliable locking sequence to 40W at this point (recycling gain ~28.5, same SOFT offset strategy as over the week-end with one set of offsets engaged before power up, one at 40W; SRM alignment done by end), so tonight we started going back to low noise while doing PI testing.

Here is the list of things we successfully did; we still need to modify the ISC LOCK code to be compatible with some of those (note that we are still on POPX, so the POP beam diverter is open):
  • Coil driver switched to low noise
  • ASC cut-offs: JLP35 for DHARD (P/Y) and CHARD (P)
  • Modified CHARD-Y 35 Hz cut-off (the new one is called "modcut"), because the current one had gain peaking between 20 and 30 Hz that was preventing us from switching ESD Y to low noise; CHARD-Y gain also lowered by 40% (from -0.7 to -0.4)
  • ESD Y switched to low noise
  • ISS3 loop off, ISS 2 ON (instructions from Kiwamu; Jenny had to reduce the actuation delay from 0.2 to 0.1 to engage the second loop)
  • OMC whitening on
  • MICH feed-forward: the -15.9 nominal gain seemed ok
  • Nominal SRCL tuning: LP 80, gain reduced by a factor of 2, feed-forward engaged with nominal gain -1
  • REFL and AS beam diverters closed (POP open as we are still on POPX)
  • ESD X in state 2 (tested bias off -- no impact on the noise)
  • ITMY ESD state switched to 2
  • Jenne realized that the OMC ASC output had railed --we switched to QPDs and stayed on QPDs for the rest of the lock, but awe were already transitioned back to high noise at that point..
The best spectrum we have achieved was at June 28, 6:00 - 6:10 UTC (with the OMC alignment railed) . Below 60 Hz we still have a lot of ASC noise, and that was expected, but there was a clear excess of noise also at 100 Hz that we didn't expect to be there. For the records, sensMon claimed 40 Mpc. We run out of time because of the 15542.6 ETMY PI, accidentally driven up while trying to damp the 15542. We lost lock at June 28, 6:35 UTC, after about 2 hours at 40W. Some notes: * we systematically lose recycling gain when we increase the power, we go from 35 at 2 W to 29 at 40W. Attempts to improve the recycling gain by changing the alignment offsets of most loops failed; * because of the lower recycling gain, the shot noise improvement at high frequency that we expect is ~30%
Comments related to this report
stefan.ballmer@LIGO.ORG - 00:14, Tuesday 28 June 2016 (27993)

Plot 1: Noise spectrum for tonight. Below 60Hz is due to ASC, and can still be addressed.

Plot 2: Auxiliary loops noise. Note the increased coupling of the mechanical resonances just below 60Hz. I suspect that we still are not quite centered in the recycling cavity.

Plot 3: Aux loop coherences

Images attached to this comment
sheila.dwyer@LIGO.ORG - 00:30, Tuesday 28 June 2016 (27994)

After this lock broke Carl and I turned on the ITM ring heaters to 0.5 Watts each, and left the end stations at 1.5 Watts each.  Carl thinks that this will help with PI, and this will also set us up to try some common TCS tuning tomorow.

jenne.driggers@LIGO.ORG - 00:49, Tuesday 28 June 2016 (27995)

Some of the things that Lisa mentioned are now in the guardian.

  • Coil drivers:  Used regular guard state
  • ASC cutoffs:  created new guard state just before ESD ETMY to do this
  • ESD ETMY to low noise: used regular guard state
  • ISS 3rd loop off, 2nd loop on: actuation delay changed in guardian, everything else was already in EngageIssSecondLoop
  • OMC whitening on:  Used guardian state in OMC lock (well, we did it by hand by copying the lines of code.  But the guardian will work)
  • MICH FF: Nominal state is in guardian NoiseTunings
  • SRCL FF: In NoiseTunings state
  • SRCL loop: gain and low pass in NoiseTunings
  • POP beam diverter commented out of CloseBeamDiverters state - can now just use guardian state
  • ESD ETMX to state 2:  Need to add this to guardian, in NoiseTunings (first make sure bias is off - may want to move this earlier, in case already using PI damping)
  • ITMY ESD:  They aren't changed in the guardian away from state 2, so they should be fine.

Attached is a screenshot of when (in PSL power terms) the OMC ASC rails.

Images attached to this comment
sheila.dwyer@LIGO.ORG - 03:03, Tuesday 28 June 2016 (27996)

For the first almost 3 hours of this lock we were toggling the gain of CSOFT P by 20 dB every 10 seconds because of a logic problem in the guardian.  Should be fixed now.

Images attached to this comment
carl.blair@LIGO.ORG - 03:50, Tuesday 28 June 2016 (27997)

Filters for PI damping have been broadened to 10Hz as the phase change over 0.5Hz for some of the filters being used was greater than 200 degrees.  
These 10Hz wide filters may be problematic for the 15541.9 and 15542.6Hz modes.  I have tested damping these modes at low amplitudes with the 10Hz wide filters and to damp, however as we reached 3 hours into this lock the 15541.9 and 15542.6 were slowly pushing their way up, the filters I have put in have about 60 degrees phase shift for 1Hz change in frequency. 
I tested iwave on this pair of modes, it tracks the largest mode very well, however once damped to a level lower than the next highest mode it runs off and tracks that mode.  This meant two iwave blocks running one on each etm pi model generally pushed their test mass with the largest amplitude mode.  I was using tau of 10.
We have a SUS_PI guardian now.  The gaurdian has 4 states managed by ISC_LOCK.  IFO_DOWN, OMC_TRACKING,  PI_DAMPING and ETMX_PI_DAMPING.  The tracking state just turns on tracking for long term testing.  The damping states turn on the bandpass damping chains with settings that have been tested today and very low gains for the settings in Terra's PI wiki. I will update the wiki tomorrow with some new settings.
The 0.5W increase in the ITM ring heaters should push the optical mode to lower frequencies, as we see PI in the 15540Hz group of modes close to the end of the RoC thermal transient (1.5-2hour in a 2-3hour transient) I am hoping this will be enough to make these instabilites a little less agressive.  I have been doing some testing of the 15kHz mode in anticipation that this TCS change will make these modes ring up more at the beginning of lock.
Before leaving I stepped the ETMY Ring heater by 0.5W total to test the idea that we can push the 15542Hz modes appart with a little heating.

 

kiwamu.izumi@LIGO.ORG - 09:12, Tuesday 28 June 2016 (28004)

The ITM ring heaters that Sheila activated seemed to have introduced a substrate lensing of about 8 uD on each optic according to the TCS simulator. The ITMX HWS saw the consistent amount of change in the substrate lensing (~ 18 uD due to the round trip lensing which gives an extra factor of two). After the ring heaters were activated, the power recycling on average was higher than the previous 41 W stretch by 1%; this could be because the last lock stretch with the ring heaters was with a slightly lower PSL power of 39 W. I attach trend of the relevant channels.

Images attached to this comment
LHO General
thomas.shaffer@LIGO.ORG - posted 00:01, Tuesday 28 June 2016 (27992)
Ops Eve Shift Summary

TITLE: 06/28 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: None
SHIFT SUMMARY: Commissioners working hard. Hit 40+Mpc for a bit.

H1 CDS (TCS)
david.barker@LIGO.ORG - posted 13:14, Thursday 23 June 2016 - last comment - 20:20, Tuesday 28 June 2016(27937)
/data file system on Hartmann Wavefront Sensing computer is full

Nutsinee, Jim, Dave:

The HWS code crashed at 07:50 PDT this morning, Nutsinee tried to restart at 11:46 PDT, but it failed. We found that the 1TB raid is 100% full (has data back to December 2014). We are contacting Aidan to see how to proceed.

 

BTW: the /data file system on h1hwsmsr is NFS mounted at the end stations, so no HWS camera information is being recorded at the moment.

Comments related to this report
david.barker@LIGO.ORG - 13:44, Thursday 23 June 2016 (27938)

We deleted December 2014 ITMX and ITMY data to free up 21GB of disk space on /data. The code now runs.

We need a long term plan on how to keep these data if they need permanent archiving.

kiwamu.izumi@LIGO.ORG - 19:38, Monday 27 June 2016 (27991)

I have restarted both X and Y HWS codes this evening.

nutsinee.kijbunchoo@LIGO.ORG - 20:20, Tuesday 28 June 2016 (28038)

The disk was full again today. I deleted Jan-Feb 2015 data from ITMX folder. Freed up 194GB. HWS code now runs again.

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