Displaying reports 69061-69080 of 83192.Go to page Start 3450 3451 3452 3453 3454 3455 3456 3457 3458 End
Reports until 16:35, Monday 20 October 2014
H1 SEI (DetChar)
krishna.venkateswara@LIGO.ORG - posted 16:35, Monday 20 October 2014 - last comment - 17:56, Monday 20 October 2014(14526)
BRS output filter modified leading to better tilt-subtraction

J. Kissel, K. Venkateswara

The output filter for the BRS included two zeroes at 8.8 mHz and two poles at 1 mHz to compensate for the real pole of the beam-balance and a zero due to the gravitational spring (proportional to d, distance between CoM and pivot). Based on the data during windy periods (see 13563 and 14422), it looks like d is roughly -35 +/- 5 microns, which corresponds to an imaginary zero at ~7.3 mHz. Since Foton doesn't allow imaginary poles, I put in a complex pole with Q of 3 as an approximation but this means that the output is going to be incorrect between 5-10 mHz.

With this new output filter in place, the tilt-subtraction is working well above ~ 20 mHz. The attached pdf shows the ASD for the ground seismometer (blue), the tilt-subtracted super-sensor (red) and the tilt-correction output (green). Wind-speeds were in the range of 20-30 mph during this measurement. Note that while the super-sensor is lowered by a factor of ~5 at 50 mHz, the subtraction near 10 mHz is limited by the approximation I made above. If we could add the imaginary pole in Foton, the subtraction would be better.

Non-image files attached to this report
Comments related to this report
krishna.venkateswara@LIGO.ORG - 17:56, Monday 20 October 2014 (14527)

Another plot in displacement units and also showing Stage 1 motion. With sensor correction, the hope is to reduce the bump at 30-50 mHz by reducing tilt-reinjection and maintain performance at 0.5 Hz.

Non-image files attached to this comment
H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 15:00, Monday 20 October 2014 (14524)
frame size differences between L1 and H1

I investigated why the H1 frame is about 20% larger than the L1 frame. Using the set of INI files in the running configuration for both DAQs, I ran them through Jim's inicheck program. I removed the systems which are H1 only (PEM at midstations and SUS-QUADTST in LVEA). To remove the frame size compression ration, I am comparing raw data rates not size of frames on disk.

  num slow chans num fast chans total data rate
L1 177k 2,550 28.9MB/s
H1  178k 2,544 30.2MB/s

So H1 has 0.4% more slow and 0.25% LESS fast channels but 4% MORE data in the science frame.

I took the H1 and L1 science frame channels lists, removed all 16Hz channels, converted L1 to H1, sorted them alphabetically and compared for fast channels missing from L1 frames or having higher datarates in the H1 frame. The PEM system stood out with the biggest differences.

This summer Robert asked for many 2kHz channels to be increased to 8kHz and some added to the science frame. Looking at the PEM channels for EX, EY and CS, H1 has 1.8MB/s more data than L1. In the above table, 28.9 + 1.8 = 30.7, close to the H1 number of 30.2 (difference is most probably due to L1-only channels like CS-CAL).

As an aside, I was surprised that the science uncompressed rate was so high compared with the frame size. For H1 this ratio is 30.2 vs 12.5 which is a compression factor of 2.4. Greg confirmed that he is seeing compression rates around 2.7 using frcheck.

I also found that the compression rate and therefore the frame size depends on the state of the interferometer. As one would suspect, if ADC data has higher AC components, the compression factor will decrease. For example, I trended the frame size against the Guardian state of the DRMI locking system, there is a clear correlation (see attached plot). The size of the frame has varied by 6%.

Images attached to this report
H1 SYS
daniel.sigg@LIGO.ORG - posted 14:23, Monday 20 October 2014 (14523)
Commissioning calendar for next 2 weeks

Here is the list of commissioning task for the next 7-14 days:

Locking team:

  1. Measure recycling gain and try explaining low value.
  2. Measure power dependence of demod phase in DRMI.
  3. Check demod phase after the IMC as function of power.
  4. Change 1f/5f relative phase and look at DRMI stability.
  5. Common hand-off to transmitted power.
  6. Lock interferometer.

Alignment team:

  1. Revisit EY green WFS beam path and look for ghost beams.
  2. Make EY green WFS work again.
  3. Install EX green WFS auto-centering hardware.
  4. Commission an arm alignment controls topology which can be used for initial alignment.
  5. Integrate green WFS into initial alignment.
  6. Commission more WFS dofs in DRMI
  7. Improve stability of DRMI alignment.

SEI/SUS team:

  1. Install new models for violin mode damping.
  2. Commission violin mode damping.
  3. Install new ESD linearization code.
  4. Commission ESD linearization.
  5. Pump HAM1 to reduced periscope vibrations(?)

RF:

  1. Make an assessment of RF cross talk into the IMC AOM.
  2. Investigate EMI radiation by the VCOs and the fixed frequency OCXO.

TCS:

  1. Finish commissioning  ring heaters and CO2 lasers.
  2. Optimize mode matching and Michelson contrast defect.
H1 DAQ (DAQ, SYS)
shivaraj.kandhasamy@LIGO.ORG - posted 11:50, Monday 20 October 2014 (14522)
Pcal Beckhoff software installed

Daniel, Thomas and shivaraj

This morning we installed Beckhoff software for the PCal at the X-end station. During the installation we restarted the Beckhoff system a couple of times. Since the PCal setup is not connected yet, we didn't test the singals. One thing that came up during the software installtion was the naming of PCal channels. Previoulsy it was decided that the PCal channels would come under CAL subsytem and would read such as H1:CAL-PCALX_SHUTTERSTATUS. However 'CAL' is a restricted word and hence we couldn't use it in the channel name as we wanted. For time being we have used 'PCL' instead of 'CAL' and the channels now read such as  H1:PCL-PCALX_SHUTTERSTATUS.

H1 SEI (DetChar, PEM)
jeffrey.kissel@LIGO.ORG - posted 11:44, Monday 20 October 2014 (14521)
Update to H1 EX GND BRS Screen
J. Kissel, K. Venkateswara

After the ground super-sensor sensor correction filter model changes to the H1ISIETMX models (see LHO aLOGs 14408 and 14452), these changes needed reflecting on the BRS overview screen.

In doing so, I identified a few bugs in the implementation that we'll fix tomorrow when we add sending the GND super sensor to HEPI to try out sensor correction there. The bugs to fix:
- The gravitational gradient damping mechanism's control output signal is monitored in the front end. That control signal's channel name has a spurious copy-and-paste "1" at the end of it, i.e.
H1:ISI-GND_BRS_ETMX_DAMPCTRLMON1
We'll correct it to be
H1:ISI-GND_BRS_ETMX_DAMPCTRLMON
- The newer filters in the GND_SENCOR block needs to have the chamber name in its filter banks, like the filters in the GND_BRS block. In addition, if we do get more of these BRSs, it'll be essential to keep clear which sensor is getting corrected and in which direction. So, the channels should change from 
H1:ISI-GND_SENSCOR_ROTVELCORR
H1:ISI-GND_SENSCOR_TORQUECORR
to
H1:ISI-GND_ETMX_SENSCOR_ROTVEL_STS_X
H1:ISI-GND_ETMX_SENSCOR_TORQUE_STS_X
(where the "CORR" after "ROTVEL" and "TORQUE" are redundant with the "COR" in "SENSCOR," so we'll remove that as well).
Images attached to this report
H1 CDS
james.batch@LIGO.ORG - posted 10:19, Monday 20 October 2014 (14520)
Rebooted projector0
Rebooted the projector0 computer, it appears that dmtviewer has a memory leak. Dmtviewer had been running for a bit over a month.  After reboot, restarted the dmtviewer with the seismic FOMs.
H1 SEI
hugh.radkins@LIGO.ORG - posted 10:18, Monday 20 October 2014 (14519)
BSC-ISI HEPI L4C Cal filter compared to BSC-HEPI L4C Cal+Sym filter

On the BSC HEPI L4C input bank there are two filters, one calibrates the raw signal to nm (Cal) and the second contains the sensor symmetrization feature around at 1hz (Sym.)

On the BSC-ISI HEPI L4C, there is only a Cal filter but this also contains the resonance notch.  Attached is the foton comparison, they are close but not exactly the same.  I'm waiting for confirmation from MIT but I think these should be the same.  Along the same lines I'm correcting the BSC-ISI HEPI L4Cto Cart matrix which I think too should be the same as the BSC-HEPI L4C to Cart matrix.

The BSC-ISI HEPI L4C filters should be the same as the BSC-HEPI L4Cs.

Images attached to this report
H1 General
jim.warner@LIGO.ORG - posted 09:32, Monday 20 October 2014 (14517)
Morning meeting summary

Beckhoff work at EX, othe Pcal work, tomorrow taking hardware to EY
HAM4&5 oplev work tomorrow
Oplev calibration on-going
ESD linearization algorithm
A number of SEI fixes, mostly software. Hugh will be working on ITMX HEPI tomorrow during maintenance, will probably require turning HEPI off.
 

H1 SEI
hugh.radkins@LIGO.ORG - posted 08:21, Monday 20 October 2014 (14516)
WHAM6 HA ISI Matrices all Correct--Safe.snap & SVN

Took HAM6 off line to correct the matrix that was wrong.  Made safe.snap & uploaded it to the SVN.  HAM6 SEI back under guardian control.

H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 08:33, Sunday 19 October 2014 (14514)
CDS model and DAQ restart report, Saturday 18th October 2014

model restarts logged for Sat 18/Oct/2014
2014_10_18 05:45 h1fw0
2014_10_18 13:27 h1fw1

both unexpected restarts.

H1 CDS (DAQ)
david.barker@LIGO.ORG - posted 12:30, Saturday 18 October 2014 - last comment - 07:36, Monday 20 October 2014(14513)
CDS model and DAQ restart report, Friday 17th October 2014

model restarts logged for Fri 17/Oct/2014
2014_10_17 07:32 h1fw1

unexpected restart of fw1, looks like additional memory did not fix this. Time will tell if frequency of restarts has been improved.

Comments related to this report
keith.thorne@LIGO.ORG - 07:36, Monday 20 October 2014 (14515)CDS, COC
We are not seeing these restarts at LLO.  I suspect it is because the H1 DAQ is writing 20% more data to disk

From the DAQ screen captures, I get the following stats
 IFO     Channels       KB/s      Comm Frame       SciFrame
L1       160,950     60,094     1,091,814,337    638,650,407
H1      165,959     65,069     1,296,128,583    790,420,874  
                              + 8%           + 19%           + 23%
So the H1 frame-writers are ingesting 8% more data and writing out ~20% more data to disk. Since L1 is right at the limit, I am not surprised that H1 is having issues. Possible solutions are (maybe) faster DAQ computers and (definitely) less data to frames. I note the L1 science frames (64s long) are just at the 10Mb/s limit while the H1 science frames are 23% over that limit. L1 may consider not adding the full suite of fast PCAL channels (when that install occurs) to ensure DAQ stability.
H1 ISC
sheila.dwyer@LIGO.ORG - posted 20:24, Friday 17 October 2014 - last comment - 10:18, Saturday 18 October 2014(14508)
DRMI is fine at 1 Watt, again.

Alexa, Sheila, Dan, Kiwamu

I was about to post the alog below, when we decided to go back to 1 Watt since everything else we have tried to get DRMI stable at 10 Watts has failed.  At 1 Watt we had no mode hopping issues, we aquire lock within 10 minutes or less, and it is stable once we lock.   This sounds like a familiar story.....

Right now we are trying to transition to 3F, we didn't suceed at 1 Watt so we are now trying at 2.9 Watts. 

The old, sad alog:

Today we tried to get PRMI to be stable again. Our working theory is that we are having these mode hopping problems beause of some bad alignment.  Our intial alingment scheme right now doesn't fix the alingment of PR3, so we have tried various methods to recover this alingment to a time when we had more stable locking.

We also got a DRMI lock, which lasted only a few minutes, and dropped at 1:53:07 october 18 UTC, that is the second video attached.   Our big victory today was that Alexa killed the fly that has been hanging out in the control room.

Non-image files attached to this report
Comments related to this report
alexan.staley@LIGO.ORG - 20:39, Friday 17 October 2014 (14510)

We tried increasing the input power to 4W; at this point DRMI was already unstable.

kiwamu.izumi@LIGO.ORG - 22:43, Friday 17 October 2014 (14511)

Alexa, Dan, Kiwamu

Tried several times of the 3f locking, but was not so successful because the SRCL loop did not like to be locked with the 3fs. Only once, we were able to transition to all the 3fs at 2.7 W. At this ponint the input element was 1, 2, 5 for PRCL, MICH and SRCL loops.

We started checking the demod phases. Surprisingly, it seems that the good demod phase for RF135 has changed from that of 10 W by more than 45 deg. MICH and SRCL show up mostly in the opposite quadrature. We should do more precise and careful adjustment for this

alexan.staley@LIGO.ORG - 10:18, Saturday 18 October 2014 (14512)

When we were at 2.7W and locked on 3f with MICH and PRCL, I measured the open loop transfer functions. The UGF and phase margin for PRCL has been the same as before (UGF of ~70Hz, with 40 deg phase margin). However, the UGF for MICH was too low, ~ 2.5 Hz.

H1 ISC
keita.kawabe@LIGO.ORG - posted 17:09, Friday 17 October 2014 (14507)
Bogus offset in POP QPD sled output

As of now there are some bogus offsets on POP QPD sled output:

H1:ASC-POP_A_PIT_OFFSET = -0.03

H1:ASC-POP_A_YAW_OFFSET = +0.66

H1:ASC-POP_B_PIT_OFFSET = -0.72

H1:ASC-POP_B_PIT_OFFSET = +0.57

 

Turns out that people set these to remember the good alignment and then forgot.

LHO General
edmond.merilh@LIGO.ORG - posted 15:58, Friday 17 October 2014 (14496)
Ops Daily Summary

08:00 LVEA is LASER HAZARD

08:15 ISS diffracted power was adjusted to 9.5% from 10.5%. refsignal=-2.06V

08:47 Aaron to X-end to re-terminate P-cal cables

08:48 Jeff B  out to LVEA to take measurements in W Bay

09:06 Commisioning Reservation System is showing "Do Not Disturb the IFO" for another day, yet the Observation Intent Bit is not set to undisturbed.

09:15 Jeff B out of LVEA

09:30 Jeff B back in the LVEA

09:57 Travis to End-Y to take pictures around P-Cal viewports. Not touching anything.

09:57 Jim and Dave to end station(s) electronics rooms

10:00 Bubba working on coms from front gate

10:29 Karen goin to midY and End Y to clean

10:49 Travis is back from Y end and going to retrieve a viewport can from the LVEA to bring back to the Y End.

10:54 Dave an Jim have returned

11:24 Karen finished cleaning duties on Y Arm.

14:30 Richard out to the LVEA for a "minute"

14:36 Richard out of LVEA

H1 ISC (ISC, TCS)
sheila.dwyer@LIGO.ORG - posted 20:54, Thursday 16 October 2014 - last comment - 20:39, Friday 17 October 2014(14492)
CO2 X laser off

We just turned off the CO2 laser.  We had seen our contrast improve from 99.1% to 99.8% (after about 7 hours at 192 mW CO2 power), and finally after about 19 hours we measured the contrast at 99.6%.  Dan has also measured the OMC mode matching, which seems to have gotten worse for ITMX (measured around 17 hours).  In the few minutes since we turned it off, the contrast has improved again.

Today we have had considerable difficulty locking DRMI, beause of the mode hopping problems.  There are many examples of short locks where the mode hopping seems to have killed the lock, some times are (all UTC, october 16th) 23:50, 23:23:50, 22:48,  22:26:27, 22:10, 20:44:20, 20:41:30, 20:36:04 and 20:34.....

Our difficulty today may or may not have been related to the TCS, it may just have been that our alingment was bad.  We did have 2 longer locks, each about 20 minutes. 

We decided to try locking PRMI, to see if we could get a better handle on alignment.  I edited the PRMI guardian (in LSC configs) so now it is using the refl air PDs, and the gains are correct now that we are using the power scaling. (110 for MICH, 22 for PRCL) The distressing news is that now PRMI has a similar mode hopping behavoir to what we see in DRMI. 

The first attached screen shot shows the way that our as camera has looked when mich was on a dark fringe most of the day today.  The second one shows it about 7 minutes after we turned the laser off.

Images attached to this report
Comments related to this report
sheila.dwyer@LIGO.ORG - 20:39, Friday 17 October 2014 (14509)

To sumarize the TCS story,

we turned on the CO2 laser for about 40 minutes at 1 Watt, realized we had overshot with the power, turned it off for about a half hour, durring which time our contrast improved.  We then turned the laser on with about 0.15 Watt (according to Greg's rotation stage calibration) or 0.19 Watt (according to Alistair's power meter calibration).  This should have been approximately right, and indeed after about 7 hours of this it seemed like our contrast had improved (from 99.1% with no TCS) to 99.8%.  After about 19 hours of TCS we measured the contrast again, and it was about 99.6%.  Dan also measured the mode matching from ITMX to the OMC.  (since ITMY has better mode matching than ITMX with no TCS, we expected that the mode matching would improve if the contrast was improved.)  Dan measurent indicated that the mode matching had gotten worse.  We turned off the TCS after about 20 hours.  This morning (about 10 hours after turning it off) Keita and I measured the contrast again; we got 99.6%.  It seems like there is a lot of variablility in our measurements of the contrast. 

The attached screen shot is an image of the as port with mich locked on the dark fringe, after TCS had been off 10 hours or so.  This is what it normally looks like, for comparison to the pictures above.

The conculsion is that we don't really understand what happened when we turned on the TCS, and we are going to wait until we have hartmann sensors and a calibration to try it again.

Images attached to this comment
H1 ISC (ISC)
aaron.sevigny@LIGO.ORG - posted 12:39, Thursday 16 October 2014 - last comment - 09:51, Monday 20 October 2014(14485)
Whitening Chassis Replacement
Replaced non functioning whitening chassis S1101631 with S1101602 on 10/15
Comments related to this report
keita.kawabe@LIGO.ORG - 08:32, Friday 17 October 2014 (14499)

Is this X end or something else?

edmond.merilh@LIGO.ORG - 09:51, Monday 20 October 2014 (14518)

It's X-End Keita.

Displaying reports 69061-69080 of 83192.Go to page Start 3450 3451 3452 3453 3454 3455 3456 3457 3458 End