The ITM ESD HV power supplies were powered on this afternoon ~4:15 PM. I believe the units have been off since the HAM6 vent.

• mostly opportunistic maintenance
• LASER back on. revovery/alignment process begun

This was done using JIm W's new script! (More on that another time)

All OpLevs look good, except ITMX Pit. Seems to be slowly drifting off, current value at 13.

FAMIS#4689

Kyle, Chandra

Isolated turbo on top of HAM 6 and spun it down, turned off scroll pump, decoupled foreline piping. Left turbo energized until bearing if fully de-levitated. 

NOTE: climbed on top of HAM 6 to do this work. 

Will de-energize turbo by Monday.

P. King, J. Oberling

Short Version:  The PSL is now up and running following the HPO water leak (first reported here, repairs reported here).

Long Version:  This morning, after giving the HPO ~48 hours to completely dry, we inspected the HPO optical surfaces.  The only thing found was some water spots on the head 1 4f lens (this was drag wiped clean); all other optical surfaces look good.  We then slowly brought up each head individually to ensure no contamination was causing the optical surfaces to glow; all good here as well.  The HPO was then successfully powered up an allowed to warm up for several minutes.  The front end came on without issue and the injection locking locked immediately.  After allowing the system to warm up for ~1 hour, I attempted to lock the PSL subsystems (PMC, FSS, ISS).  The PMC did not want to lock; according to Peter this was likely due to a slight horizontal misalignment (this is seen in a trend of the QPD that lives in the ISS box.  I unfortunately don't have a copy of it).  I returned to the enclosure and tweaked the beam alignment into the PMC and it locked without issue.  I then tweaked the PMC alignment further to maximize the power throughput.  PMC now has a visibility of ~80% with ~122W transmitted (with ISS on).  The FSS and ISS both locked without issue.  The PSL is now operational and fully recovered from the water leak.

The RTD module in the Beckhoff Link chassis what replaced this morning.  This module was showing problems since installation and was low on the list for replacement.  This morning we took advantage of PSL outage to take down the end station Beckhoff chassis to swap out this module. (EL3202)
The glitching is gone.

Last week HAM6's vacuum gauges were upgraded from the original pirani-coldcathode pair to the new Beckhoff Infinicon BPG-402. The new gauge has two channels (MOD1 and MOD2) which both record the vacuum over the full range of atmospheric (760 Torr) down to 1.e-09 Torr

I have renamed the archived Cold-Cathode minute trend files to match the new MOD1 name. In other words, if you ask for minute trend data prior to 8/10 for channel H0:VAC-LX_Y0_PT110_MOD1_PRESS_TORR you will be given data for the CC channel H0:VAC-LX_Y0_PT110B_PRESS_TORR. Note the archvied Pirani data is not accessible from NDS. I will write code to obtain data directly from the raw minute trend files if this is needed.

I will make the same changes for the other gauges which have been upgraded (PT170 and PT180)

Peter, Dave:

we modified h1pslfss under WP6100 to fix two bugs:

temperature channel inputs to DINCO for OOL and Ambient were swapped in the model

DINCO DAC outputs drive chans 08-11 and not 12-15

model was restarted, no DAQ restart was required.

Kyle, Chandra

Valved in IP and valved out TP. Pressure fell from 1.1e-6 Torr to 9e-7 Torr when IP was valved in and now is slowly rising with TP valved out (currently at 1.2e-6 Torr). After IP reaches thermal equilibrium we expect pressure to fall again. After that is observed we will shut down turbo + scroll (hopefully this afternoon).

Note: verified the MPC controller was ON and programmed for 500 L/s pump prior to valving back in. Read -5700 V. Now reads -5000 V with load.

LLO site was generally unaffected by the major flooding in Livingston and Baton Rouge area.

However, access to the site was difficult and hazardous so the site was closed Friday thru Wednesday.

Many staff had their homes inundated with river flood water.

All staff and visitors were either directly or indirectly affected by this event and many are still helping with the clean up and the recovery efforts underway.

The site is now fully open and has returned to regular operation.

Thanks to all of the LIGO family who have reached out to help those in need.

Note: The monthly Science Saturday event scheduled for tomorrow (08/20/2016) has been canceled.

Manual temp control via multiple variacs -> 10% decrease every few hours

SEI - progress made to miigate tripping of HAM6 ISI when fast shutter is activated

SUS -  no report

CDS - hopeful to close out gust meter work today; PEM AA chassis repaired; TCS AA chassis repaired. Both AA chassis suffered buffer chip damage most likely due to 'hot-swapping'.

CDS SW - continuing worl to address Frame Writer instability issues. Also, formulate a plan for '02

PSL - water leak is repaired. Optics have been wiped. Further inspection of collateral water issues will be performed. Power up of LASER hopeful for this afternoon. TCSY is back up and fully functional at full power. No hard evidence of BS OpLev glitching noted. If said glitchiness persists there will be a plan to swap out the laser.

VAC - will transition HAM6 to ION pump. RGA bakeout work between HAMs 4 and 5 will continue into tomorrow. Length of time most likely will depend on commissioners being able to return to their tasks.

FAC - Bubba will inish eyewash station inspections. DI skid will be re-plumbed'

• PSL still down

Attached is a plot of the cooling water flow rate for the 4 laser heads after replacement of the
burst hose (over head 3) and replacement of the head 4 flow sensor.  Also attached is a 30-day
trend plot of the same signals.  The large jump in flow rates about 6 days into the plot coincides
with replacement of the water manifold located under the table.

    At this stage it is too early to tell if replacing the head 4 flow sensor fixes the problem
with the all over the place signal seen in the 30-day trend plot.

Evan G., Jeff K.

Summary:
We measured the transfer functions of the OMC DCPD anti-aliasing (AA) module paths of ch13-16 for chassis S1102788. We measure this because the filter board was modified for these channels (LHO aLOG 28010). This is similar to the measurement Kiwamu made in LHO aLOG 21123. The OMC DCPD AA channels are 13 and 14 for DCPD A and B, respectively. The OMC PI AA channels are 15 and 16. We find that the notch behaviour of channel 13 matches what Kiwamu found in LHO aLOG 21123, but the notch of channel 14 is distorted (broken?). Channels 15 and 16 do not have the same notch behaviour (as to be expected for the PI paths, matching LHO aLOG 28085). These differences--compared to the calibration model reference AA filter--are below 1% in magnitude and less than 1 degree in phase below 7 kHz. While the calibration group is unaffected by the broken channel 14, noise from 65 kHz will be aliased down into the detection band. We should consider fixing this.

Details:
The setup for the measurements is shown in the first attachment, and the reference measurement (to remove the gain of the single ended to differential box) is shown in attachment 2. Each transfer function measurement is normalized by the reference measurement transfer function.

Data is saved in /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O2/H1/Measurements/OMCAAChassis

Analysis script is saved as /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O2/H1/Measurements/OMCAAChassis/process_aachassis_data_20160818.m

Plots are shown in the third attachment. Of particular note is to compare the new measurements to the AA filter model. Channel 14 (OMC DCPD B) now has a different behaviour near the notch. The difference is below 1% in magnitude and 1 degree in phase below 7 kHz, and does not force a revision in the calibration model reference AA filter.

I have been taking spectra from the SR785 (WP6005) whenever I get a chance over the last week to see if there is any evidence of three mode interactions in the 60kHz to 70kHz region that we will not be sensitive to with the aliased OMC DCPD HF channels that we normally analyze.
There is a consistent peak at 62935Hz, this peak is present with no optical power in the arm cavities.
There are several other more transient peaks, one of the times several had large amplitudes is shown in the first figure.
The largest peak is at 63776Hz  The maximum amplitude seen was 5E-6  This is about the same as the 18040Hz mode when it is 2 orders of magnitude above thermal noise and 2 orders of magnitude under unlocking the cavity.
The second largest is at 70160Hz and the third largest at 62336.

There is no evidence of peaks in DARM at this time at the expected aliased frequencies 1760Hz,  3200Hz or 4624Hz and the peaks that appear in the HF channels that do not appear in the normal DCPD channels do not coincide in frequency, see the second image.

Summary:

The high freqency calibration lines injected at the end of O1 (alog 24843) were analyzed to estimate the sensing function at those frequencies and compare it to the matlab DARM model. The calibration at frequencies above few kHz shows deviation from the model. The upward trend in the residual, as shown in the plot below, looks like the effect of the bulk elastic deformation of the testmass due to the misalignment of the pcal beams. However, this is not a definitive conclusion because the phase doesnot seems to suffer so much and also the error bars are too large to make a definitive statement. A set of measurement might be necessary to see if this effect is in fact reproducible.

Details:

The SLM tool was used to estimate the line amplitude with FFT duration listed below for each individual lines. The mean of the several data points was taken as the central value and the coherence of the measurement was estimated using magnitude squared coherence:

Coh = (A.B*)² / A² * B²

where A  and B are amplitude of DARM_ERR and PCAL_PD channels readout.

Freq    Amplitude    Start Time           Stop Time        Duration     FFT       Data points   Optical Gain
(Hz)           (ct)        (mm-dd UTC)     (mm-dd UTC)    (hh:mm)    (mins)      (#'s)             (kappa_C)
------------------------------------------------------------------------------------------------------------------------------------------
1001.3       35k         01-09 22:45     01-10 00:05         01:20         10           8                   0.995 

1501.3       35k         01-09 21:12     01-09 22:42         01:30         10           9                   0.995

2001.3       35k         01-09 18:38     01-09 21:03        02:25          10          13                  1.00

2501.3       40k         01-09 12:13     01-09 18:31        06:18          30          12                  0.995
 
3001.3       35k         01-10 00:09     01-10 04:38        04:29          30           8                   0.99-0.96 (Fluctuating)

3501.3       35k         01-10 04:41     01-10 12:07        05:26          30          10                  0.99               

4001.3       40k         01-09 04:11     01-09 12:04        07:55          60           5                   1.00

4501.3       40k         01-10 17:38     01-11 06:02        12:24          60          11                   0.99

5001.3       40k         01-11 06:18     01-11 15:00        ~9:00          60           9                    -----

These additional data points were added to one of the Pcal sweep done earlier during the run. In this case I picked the data from 2015-10-28. The optical gain during this sweep measurement was around 0.985 compared to 0.99-1.00 (from table above) during the high frequency injections. These optical gains were eye-balled from the detchar summary pages so I considered them within the margin of error and thus didnot do any correction.  A new parameter file is created to run this as a new set of measurement. The parameter file is stored at the following location:

ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O1/H1/Scripts/DARMOLGTFs/H1DARMparams_20151028E.m 

A script used make the plot attached above and save the output as a mat file is located here:

ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O1/H1/Scripts/DARMOLGTFs/make_sensing_HF.m 

The result of the the above script is saved at the following location and is also attached to this alog.

ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O1/H1/Resulta/DARMOLGTFs/2015-10-28E_H1DARM_HF_sensing.mat