Fault Report 4683
WP 6211

One of the binary cards inside IO Chassis SEIEY was replaced this morning. This was to fix the remote auto-zero function for the STS-2 chassis. Hugh did a functionality check for the binary input/outputs for associated card. The h1seiey IO chassis and front end computer were restarted.

J. Batch, F. Clara, H. Radkins

WP 6214

Dave, Jim, Jamie

Added 24G of RAM to h1nds0 to bring a total of 72GB.  Increased daqd's memory buffer usage in the daqdrc from 50 to 100. Jamie tested his application that collects recent data, which now works properly.

This was actually done in two steps, the first try installed a total of 96GB.  We determined that was far more than was needed, so we backed that out to a total of 72GB, made up of 3-16GB DIMM in the first bank, 3-8GB DIMM in the second bank.

The LHO DMT machines were updated today with the gstlal-calibration-1.0.3 package.  The GDS pipeline was restrated to work from this package at 1159637032. 

For the record, the chiller controller software versions for both crystal chiller and diode chiller are:
  CCC-3
  Firmware-Vers. 0.82

    That does not necessarily imply that a controller for the diode chiller can be replaced with one from
a crystal chiller and vice versa.

TCS-X: Full, level at 29.0, 3.7 gpm, 20.5 deg. C

TCS-Y: found water level at 4.3, added 500 mL water, raised water level to 8.7, 4.0 gpm, 20.3 deg. C

Attached are what the signals from the Kobold vortex flow sensors look like as read across
a 240-ohm resistor.

TEK00001.png shows the signals corresponding to switching off and back on the chiller.
TEK00002.png shows the signal decay from the power meter circuit flow sensor when the
  chiller is switched off.
TEK00004.png both signals when the chiller is switched off.
TEK00005.png looking for glitches when one of the sensors drops
TEK00007.png both signals when the chiller is switched off, only this this both outputs
  fell to zero within the same oscilloscope sweep
TEK00008.png both flow sensors were physically disconnected to simulate a power failure or
  dramatic sensor failure.
TEK00010.png the power meter flow sensor output was switched off

    There are a couple of things of interest to note:
 1.  The signal from the sensors is much "cleaner" than what comes out of data acquisition,
most likely due to the digitisation of the readout Beckhoff terminal.
 2.  Using an AC mains powered oscilloscope introduces a large 60 Hz signal on top of whatever
is there.  A battery power oscilloscope was used for these measurements.

Time-dependent parameter ("kappas") trends calculated from two lock stretches on September are attached to this report.

It seems that the front-end produced fairly smooth kappas several hours after the most recent update of the front-end setttings (LHO alog 29992). See figures 1 and 2.

However, from later lock stretches on September 30 (after the Tuesday activites), it looks like the synchronized oscillators for SUS line were synched with an incorrect phase of 143.6 degress w.r.t. each other (see KAPPA_TST values in Fig. 3 and TF phase in Fig. 4). A similar issue was reported in the previous report (LHO alog 29992). I was able to fix the problem for this particular line by resetting the line frequency to 0 Hz (turning off the line) in the SUS-ETMY model and then setting it back to its nominal state 35.9 Hz (see Fig. 5). We probably need to check "FIXED_PHASE_OSC_WITH_CONTROL.c" for bugs.

A while ago we noticed that the auxillary loops have had increased noise compared to O1.  Here is a plot verry similar to what I posted in 30032, but with correct labels. 

Here is a more detailed timeline:

March 8th, the noise is pretty much the same as O1. 

March 12th: a 2W lock where the low frequency noise is similar to O1, but the shot noise is high. 

March 14th-20th, we were down for grouting work in which I think we lost the green camera references, alignment redone March 19th.

March 20th the exposure of the PR2 camera was increased from 500 to 1 million, then reset to 1000 March 21st.  Since the camera was saturated at 1000, I have now reset it to the old exposure of 500. 

I cannot seem to get data from late march until April 2nd, when the noise is already elevated.

April 4th the HPO is turned on, and we are down for several weeks, the noise stays around.  

So, this noise could be due to some clipping or other problem that was introduced when we lost our alingment references.  

TITLE: 10/04 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: PSL down.  Work continues in the morning.  Calling it a night due to no laser.
LOG:  None
 

For reasons best known to itself, the diode chiller is no longer cooling the diodes but heating them up.
This was the most likely reason why the laser tripped out when it was fired up this afternoon.

    Another report will follow later about the signals we observed from the front end flow meter and the
power meter circuit flow meter.

   The crystal chiller has been left running.  The diode chiller is off.  A new controller for it is
expected soon.




Jason/Peter

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).

2:30pm local

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

Next fill due Wednesday.

* 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

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.)

In an attempt to bring some clarity into the beam jitter discussion I looked at the Gouy phase evolution of the input beam. I collected distance and focal length information from a variety of sources, notably T1200470 and E1200616.

The biggest uncertainty I had was the PSL persicope to HAM1 viewport distance - if someone knows that, let me know.

The MATLAB script with all the numbers is in ~controls/sballmer/20160930/inputBeamCalc.m. It creates a structure of the following form, fully describing the beam and optical mode:

IMC =
    lambda: 1.0640e-06               % The wavelength in m
         q: 0.2325 +13.3832i          % The input Gaussian beam parameter q=z+izR in m
         N: 4                                 % number of optics
      dist: [16.2406 16.2406 0.2325 0.2325 0] % Distances between the optics (one more than N)
      ifoc: [0.0731 0 0 0]               % inverse focal length for all lenses and mirrors (f=R/2 for mirror)
     label: {'MC2'  'MC3'  'Waist'  'MC1'} % optic names
 

The attached .mat file contains the following structures of that form::

IMP:    Input beam: From PSL periscope to MC3
IMC:    Input Mode Cleaner
IMCp:  Input Mode Cleaner from MC1 to MC3 only (output path inside IMC)
IM:      Input Mirros: from IMC to PRM
PRC:  Power Recycling Cavity forward path
PRCr: Power Recycling Cavity return path
PRCrt:Power Recycling Cavity round trip

Below are plots and data for the different beam segments.

This is a plot of the jitter measured by the IMC WFS DC PIT/YAW sensors during last nights lock. The 280 Hz periscope peak reaches about 1x10^-4/√Hz in relative pointing noise, or about 3x10^-4 rms. The relative pointing noise out of the HPO is about 2x10^-5/√Hz at 300 Hz. After the attenuation through the PMC this would correspond to a level below 10^-6/√Hz. The jitter peaks show up in DARM, if they are high enough. This is clearly visible in the coherence spectra.

The ISS second loop control signal is an indication of the intensity noise after the mode cleaner with only the first loop on. The flat noise level above 200 Hz is around 3x10^-6/√Hz in RIN, with peaks around 240 Hz, 430 Hz, 580 Hz and 700 Hz. Comparing this to the free-running noise in alog 29778 shows this RIN level at 10^^-5/√Hz. We can also compare this with the DBB measurements, such as in alog 29754: the intensity noise after the HPO shows a 1/f behaviour and no peaks. Looking at the numbers it explains the noise below 300 Hz. It looks like a flat noise at the 10^-5 level including the above peaks gets added to the free-running intensity noise after the PMC. The peaks in the controls signal of the second loop ISS line up with peaks visible in the pointing noise. But, neither the numbers nor the spectral shape matches. These peaks have coherence with DARM.

Kiwamu, Sudarshan, Jenne, Darkhan

Overview

EPICS records that are used for calculating DARM time-dependent parameters ("kappas"), were updated using corrected DARM model (with the correct sign of the ETMY_L3_DRIVEALIGN_L2L gain). These EPICS values result in reasonable kappa values (see details).

"512 Hz DAQ downsampling" filter was installed into CAL-CS synched oscillator that replicates 35.9 Hz cal. line (ESD).

Investigations showed that the synched oscillators for 35.9 Hz cal. line were running at 180 degrees out of phase w.r.t. each other. They got synched to the same phase after I played some with the oscillator settings in CAL-CS model.

Jenne noticed that today f_C was oscillating between 320 and 360 Hz at the time-scale of ~20s. This issue was resolved by turning on low-pass filters in the CAL-CS model.

Details

Sudarshan confirmed that kappas calculated from SLM tool data using these EPICS values are within reasonable ranges. After updating EPICS records one of the issues was that κ_TST calculated in the front-end was around -1.0. Further investigations showed that the synched oscillators for 35.9 Hz cal. line in SUS-ETMY and CAL-CS models were running at 180 degrees out of phase w.r.t. each other. We could get rid of the discrepancy by setting the phase of the CAL-CS oscillator to 180 degrees (see attached plot).

After changing settings on the synchronized oscillators their phases somehow got synchronized. So, I removed 180 degrees of an additional phase in the CAL-CS oscillator. It is still not clear what was the cause for the phase of two synched oscillators being exactly 180 degrees off. Now the oscillator outputs (after the 512 Hz DAQ downsampling) are pretty much the same (TF measurement at 35.9 Hz is attached).

New EPICS values and corresponding logs were commited to calibration SVN. The values were accepted in SDF_OVERVIEW.

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/Hz^1/2. This would imply a noise in DARM that is more than a factor of 10 below DARM shot noise.