Displaying reports 53861-53880 of 83228.Go to page Start 2690 2691 2692 2693 2694 2695 2696 2697 2698 End
Reports until 16:31, Monday 03 October 2016
LHO VE
chandra.romel@LIGO.ORG - posted 16:31, Monday 03 October 2016 (30191)
CP4 experiment
Last week (Sept. 30th) I set CP4 in manual mode and doubled the LLCV to double nominal value (up to 66% open). Fill from 92% to 100% full took about 17 min. and another hour to see LN2 spew out the exhaust. Then I set LLCV back to nominal 32% open (actually slightly less than nominal probably given the level of the Dewar) to see how long it would take to boil back to 92% full. Answer is ~ 26 hrs. 

Today I remembered to set the CP4 PI lower limit setting back to 20% (important when Dewar gets filled).
LHO VE
chandra.romel@LIGO.ORG - posted 16:19, Monday 03 October 2016 (30190)
CP3 overfill
2:30pm local

20 sec. to overfill CP3. Left bypass exhaust valve open.

Next fill due Wednesday.

LHO General
patrick.thomas@LIGO.ORG - posted 16:02, Monday 03 October 2016 (30188)
Ops Day Summary
* PSL down all shift for troubleshooting *

15:09 UTC Jeff B. opening rollup door between cleaning and receiving area
15:48 UTC Jim B. taking down h1lsc0 frontend to allow Filiberto to turn off IO chassis. (WP 6197)
16:13 UTC Ed starting WP 6198
16:24 UTC Filiberto done
16:33 UTC Filiberto to end Y EE room to look at remote reset for STS2 seismometer. (Hugh reports it is not working)
16:40 UTC Jeff B. starting check of dust monitors in LVEA
16:42 UTC Cheryl to TCSY table to check for water leaks
16:43 UTC Betsy starting ESD charging measurements on both ETMs
16:51 UTC Peter to PSL rack to look at connectors and signals related to chiller
16:59 UTC Hugh going to ITMX for CPS work (WP 6207)
17:05 UTC Jeff B. moving to end Y (compressor room and VEA)
17:15 UTC Gerardo to LVEA to check TCS chiller pipes for water leaks
17:16 UTC Richard transitioning LVEA to laser safe
17:19 UTC Filiberto's work on STS seismometer at end Y tripped ISI. Jim W. turned off sensor correction. Betsy restarting ESD charge measurements.
17:29 UTC LVEA transitioned to laser safe
17:29 UTC Jeff B. moving to end X (compressor room and VEA)
17:37 UTC Hugh back to ITMX
17:37 UTC Cheryl done, checked both TCS tables, no signs of water.
17:47 UTC Betsy turning TCS laser back on (tripped, cause unknown). Holding off on charge measurements due to multiples ISI trips at both end stations
17:53 UTC Jamie starting guardian update (WP 6208)
17:54 UTC Gerardo done
17:59 UTC Ed done
18:06 UTC Jeff B. done
18:12 UTC Hugh to end Y to look at CPS
18:22 UTC Chandra going for jog on X arm
18:28 UTC Filiberto done
19:04 UTC Peter and Jason breaking for lunch
19:52 UTC Betsy restarting charge measurements
20:19 UTC Peter and Jason back to LVEA PSL racks
20:34 UTC Hugh to LVEA to check CPS for BS
20:52 UTC ETM charge measurements done
20:55 UTC Chandra to mid Y to fill CP3
22:00 UTC Betsy to optics lab
22:05 UTC Vern to LVEA to check on Peter and Jason
22:50 UTC Photographer for Science magazine through gate

Forgot to log time: Karen and Christina to LVEA to swift
H1 SUS
betsy.weaver@LIGO.ORG - posted 14:39, Monday 03 October 2016 - last comment - 16:13, Monday 03 October 2016(30187)
Weekly ~TUES ETM charge measurements taken

Since the PSL was being worked on this morning, I took the opportunity to take the ETM charge measurements so that we don't have to take up time tomorrow.  The coherence data looks good, however NDS is whining about something and won't let me produce the long trend.  Show me the money!

Soooo, TBC...

 

(Note, I had to restart the measurements a few times this morning since the ISIs kept tripping unexpectedly with expected SEI work.)

Comments related to this report
jeffrey.kissel@LIGO.ORG - 16:13, Monday 03 October 2016 (30189)
NDS likes me more than Betsy. 

Conclusion: We can wait another week or so before flipping the biases again. ETMY is close to needing it than ETMX, but ETMY has one quadrant that's got ~20V more negative charge than the rest, so we'll let it accumulate more positive ions and flip them both at the same time again.

Images attached to this comment
H1 GRD
jameson.rollins@LIGO.ORG - posted 14:31, Monday 03 October 2016 (30186)
lockloss tool update

I updated the lockloss tool to take advantages of some features of the new guardian release.  It can now find lockloss times over the last two days faster by using NDS instead of guardlog to look for the times.  The log display is also fixed.

H1 PSL
edmond.merilh@LIGO.ORG - posted 14:11, Monday 03 October 2016 (30184)
PSL Weekly Report - 10 Day Trends FAMIS #6116

Also included is a zoomed view of the OSC-DCHILTEMP channel which shows periods of oscillations. THought this may be of interest. Not much out of the ordinary otherwise, barring the excessive trips.

Images attached to this report
H1 GRD
jameson.rollins@LIGO.ORG - posted 11:53, Monday 03 October 2016 (30180)
minor guardian upgrade

I upgraded guardian to v1.0.2, which is a minor upgrade to fix a couple of small issues and make some small UI improvements:

H1 AOS
jeffrey.bartlett@LIGO.ORG - posted 11:37, Monday 03 October 2016 (30178)
Dust Monitor Quaterly Testing FAMIS #7312
   Did quarterly Zero Count and Flow Testings for the vacuum connected dust monitors. NOTE: Did not go into the PSL enclosure. Will check these dust monitors on next PSL entry.

   All monitors were Zero Count. Had to run the Zero Test a couple of times to clean and zero the dust monitor at HAM6. 

   All monitors are with in flow range (2.8l/m +- 5%). The flows on the dust monitor at HAM6 and in the Biergarten are a bit on the low side. Will check the trend on the next inspection, and adjust the flows as necessary. 

   All vacuum pumps checked out: temperatures all <150f and vacuum readings with in range (19inHg +-5%). Made minor by-pass flow adjustments on the CS and End-X vacuum pumps.     
H1 SEI
hugh.radkins@LIGO.ORG - posted 11:06, Monday 03 October 2016 - last comment - 14:01, Monday 03 October 2016(30174)
WBSC3 ITMX CPS Noise Fixed--cycle plugging of probe & card

WP 6207

Nutsinnee plotted the CPS sensor noise and we see there are a few with elevated levels. So this morning we unplugged the probes and unseated/reseated all the corner3 cards several times.  The St1 noise on H3 cleared up but the Stage2 H3 was still noisy.  So, returned to the floor and reseated St2H3 card several times.  Now it seems much better--see attached.  The low frequency noise (below 20 Hz) is from the stages not being isolated.

Images attached to this report
Comments related to this report
hugh.radkins@LIGO.ORG - 13:10, Monday 03 October 2016 (30182)

Repeated exercise on ETMY--un- and re-seated the V2 card several times.  Now the noise level looks like the others, see attached.

Images attached to this comment
hugh.radkins@LIGO.ORG - 14:01, Monday 03 October 2016 (30185)

Ditto for the BS (BSC2)--Un and re seated the St1 H1 satellite card several times and now the noise looks like the others and below the NOISE curve.

Images attached to this comment
H1 TCS (TCS)
vernon.sandberg@LIGO.ORG - posted 10:29, Monday 03 October 2016 - last comment - 12:13, Monday 03 October 2016(30170)
TCS Chiller Status and Fill Report

Gerardo and Vern

TCS-X: Full no water added, 3.9 gal/min, 20.0 deg C.

TCS-Y: found water level to be 6.6, added 750 mL to raise gauge to 8.6, 4.0 gal/min, 19.8 deg. C.  Unusual fill pattern, first 500 mL showed no sign on gauge then suddenly the gauge ball droped to 5.0 and climbed with the addition of the last 250 mL of water.

Noticed the icons on the two chiller control panels were different. TCS-X displayed horizontal bars. TCS-Y displayed chevrons pointing up. 

Comments related to this report
betsy.weaver@LIGO.ORG - 10:40, Monday 03 October 2016 (30171)

I'm guessing that the TCS-Y symbols are related to the fact that this laser tripped right when you guys were refilling the water for some reason (9:45am).

matthew.heintze@LIGO.ORG - 10:47, Monday 03 October 2016 (30172)

Yes this is normal. Means that the chiller is heating with the arrows pointing up (or cooling when pointing down) so that the water is at the setpoint of the chiller

cheryl.vorvick@LIGO.ORG - 11:03, Monday 03 October 2016 (30173)TCS

At Richard's request, I inspected the inside of both TCS tables, and found nothing, no drips and no sign of water, the tables are dry.

I inspected TCSY first, then TCSX.

betsy.weaver@LIGO.ORG - 11:06, Monday 03 October 2016 (30175)

Also, apparently both Gerardo and I, separately, walked the length of the piping and found no leaks.

 

Attached is this morning's story of laser power.

Images attached to this comment
alastair.heptonstall@LIGO.ORG - 11:36, Monday 03 October 2016 (30177)

It looks like there is a small increase in temperature on the laser which causes a power output increase from the laser.  Following that the laser trips off, and the Guardian code then starts trying to relock the laser.  

We'll need to  think about the right way to get Guardian to "see" that the laser has tripped off - we should get it to check the laser error channels.  Anyway that's why the temperature of the chiller has those steps in it.

I'm not sure how sensibly Guardian will react if you just restart the laser without restarting Guardian.  The reason I say this is because it typically takes ~30mins for the laser to come into thermal equilibrium during which time Guardian won't be able to lock it.  Also while Guardian is hunting for a locking point it will occasionally be stepping the chiller temperature (as shown in the chart) which may in turn increase the time taken for the laser to reach an equilibrium temperature.  This logic isn't well baked in to the current Guardian code which at the moment locks the laser when it is reasonably stable (ie after 30mins of running unlocked).

betsy.weaver@LIGO.ORG - 11:58, Monday 03 October 2016 (30179)

I'm thinking the anomolous note Vern mentions in the first post on this thread is the culprit for the laser trip:  The indicator float bobbled way low and then rose while they were filling.  So, I think an air bubble pushed out from under the filter and dropped the level briefly, thus triggering a low water level trip.

 

This adds to my thought that maybe the mystery water "loss" issue is actually not a water loss at all, but an air loss.  Maybe we didn't fill the chiller all the way up when we found the chiller dry on Wed, and we are still "topping it off'.  as I pointed out last week, the indicator goes/stays low after you push air out from under the filter.  Today, I played with this more and was again able to bleed more air out from under the puffy filter fabric which then left the indicator low.  I had to fill another 225mL just in playing with it.  Attached are pix of the X and Y filter while water is running thru.  Note how the Y filter fabric is being pushed up towards the surface of the water, while the X one has more of a trough down the middle?  (Use your imagination, it is much more obvious when standing over it and pushing it around with a gloved hand or hose tool). 

 

They added 1.3gal (5L) on Wed when they found it dry.  We've added ~a gallon (3800mL) since then, in small ~500mL batches.  I'm looking up the capacity of the chiller...

Images attached to this comment
betsy.weaver@LIGO.ORG - 12:13, Monday 03 October 2016 (30181)

The chiller reservoir volume is listed as 7.2L (1.9 gal).

We've added ~5L plus ~3L since Wed - given some error bar on these plus a little reasonable amount of bubble bleeding, we might find that the indicator reading settles out at "full".  That's one theory anyways...

We have inspected the tables, the piping and the chillers 3 times since last Tues and cannot find any loss of water.

H1 ISC
kiwamu.izumi@LIGO.ORG - posted 16:55, Friday 30 September 2016 - last comment - 11:15, Monday 03 October 2016(30115)
Spectral shape of the noise we are tyring to hunt

I have done a cross correlation analysis of the two OMC DCPDs in order to study the spectral shape of the broad band noise that has been limiting the sensitivity in 200-1000 Hz band. Here are some results.

The red curve is cross-correlated noise of the two DCPDs in terms of the DCPD current in mA (with DARM loop effect removed).The data I used is a lock stretch from Sep. 26th which lasted for 6 hours in undisturbed. The frequency resolution or bandwidth is set to 0.1 Hz. The data length is 3 hours starting at 9:00:00 UTC of the day. The DARM suppression is taken out from OMC DCPD SUM. I have used the latest PreER10 DARM model (29931) to obtain a reasonable DARM suppression function. As we all know, there is high noise in 200-1000 Hz whose level is as high as shot noise (or null stream shown in green) in this frequency band.

I also made another plot, which is an overlay of 11 cross correlated spectra each of which is from different time but from the same lock stretch. See below.

This time, the frequency resolution is set to 1 Hz, so that we can get several FFTs out of the same lock stretch. Each spectrum is produced by an 18 minutes integration. As shown in the plot, there was one spectrum which is polluted by some kind of glitch. Otherwise, the shape of noise stayed almost unchanged over 3 hours. Also fig files are available.

Images attached to this report
Non-image files attached to this report
Comments related to this report
kiwamu.izumi@LIGO.ORG - 11:15, Monday 03 October 2016 (30176)

There was a question of whether the cross-spectrum noise was from readout electronics or not. I have checked it by looking at dark noise from this past weekend in which laser happened to be off.

I conclude that the excess noise we see at around 400 Hz is not from dark noise or similar readout noise. In fact the dark noise level above 100 Hz was found to be consistent with a measurement a year ago (20526). Things look good to me. The attached is a plot of the dark noise spectra.

DCPD settings:

  • First stage of the whitenings is engaged.
  • High-Z (400 Ohms)
Images attached to this comment
H1 ISC
evan.hall@LIGO.ORG - posted 18:44, Wednesday 21 September 2016 - last comment - 17:13, Monday 03 October 2016(29893)
Frequency noise coupling looks OK

Here is a frequency noise coupling transfer function during tonight's lock.

I calibrated REFL9 into watts using a the factor 2900 V/W (from the diode to the output of the demodulator) and 12 dB, −21 dB, and 2 V/V for the analog and digital signal gains.

If the loop is shot-noise-limited (with 4.6 mW on the diode), this implies a noise of about 40 pW/Hz1/2. This would imply a noise in DARM that is more than a factor of 10 below DARM shot noise.

Images attached to this report
Non-image files attached to this report
Comments related to this report
evan.hall@LIGO.ORG - 17:13, Monday 03 October 2016 (30192)

Daniel and I spent some time looking at the various CARM error and control signals we have on hand.

Here we have referred the fast (ao) control signal back to the error point in watts. The horizontal line is the shot noise for 5 mW.

The slow control signal (LSC-REFL_SERVO_SLOW) would also probably work as a proxy for the error point, once properly referred. The error readback (LSC-REFL_SERVO_ERR) is heavily contaminated by some kind of white noise. Ditto LSC-REFL_A_RF9_I_ERR.

Images attached to this comment
H1 CAL
madeline.wade@LIGO.ORG - posted 08:56, Tuesday 13 September 2016 - last comment - 13:12, Monday 03 October 2016(29651)
New GDS calibration filters

I have created a new GDS calibration FIR filters file.  The included filters are designed to correct output of the front-end CALCS calibration, improving accuracy at high frequencies on ~10% level.  This new filters file contains more aggressive high-pass filters with a cutoff of 9 Hz and contains accurate values for EP1-9 for use in the kappa calculations.  The new filters file can be found in the calibraiton SVN:

aligocalibration/trunk/Runs/PreER10/GDSFilters/H1GDS_1156183417.npz

This filter was created using calibration SVN version #3295 and following instructions outlined here.

Attached are plots of the corrections applied to DELTAL_RESIDUAL and each of the DELTAL_CTRL_PUM/UIM/TST/ channels (all DELTAL_CTRL_* channels receive the same corrections).  Attached are also plots comparing the h(t) spectrum for some ER9 data (1152076416-1152076544) calibrated using this filters file with output of the front-end CALCS model.  The agreement is at the expected level given the corrections include in the GDS filters.

Images attached to this report
Non-image files attached to this report
Comments related to this report
madeline.wade@LIGO.ORG - 10:25, Tuesday 13 September 2016 (29653)

The GDS calibration pipeline was restarted at 1157822672 with the above new filters file.

madeline.wade@LIGO.ORG - 13:12, Monday 03 October 2016 (30183)

These filters include the use of a tukey window around the final time domain filter.  This seemed to fix the spectral leakage issues seen by downstream tools.  I believe the previous filters were not falling off smoothly enough and were adding low-frequency features to the h(t) data.  This become noticable after switching to double precision channels, because the old dewhitening filters in use with the (whitened) single precision channels included the tukey window.  Since these dewhitening filters were no longer in use when we switched to double precision channels without whitening, the issues with the residual and control correction filters became obvious.

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