HWS code stopped during the weekend because the disk ran out of space. I deleted some of the old data and the scripts are running again. I'm working on a script that will delete old data automatically.

Status / Work Permit review

SEI - nothing to report. Tues plans to examine the IMTY coild driver

SUS - No report

CDS - (for Tues)ITMY SEI coil driver investigation/ITM cameras. May restart baffle PD boxes

PSL - ongoing chiller flow sensor errors causing laser trips. 

VAC - BSC Ion pump repcaement scheduled for Tues

FAC - Divers on site to inspect fire water tank.

Software - revisions to be made to GDS programs. Additional framewriter to be added to collect data from concentrator.

A TV crew froim Hong Kong will be on site tomorrow

According to T1500556, current settings for test mass oplevs are:

ITMY oplev PIT noise is close to the DAQ noise floor at about 3Hz, and the DAQ noise dominates the RMS down to 0.7Hz or so. ITMX is OK for RMS due to double 1:10 whitening, but not much better at 3Hz. Not good for oplev damping.

Also it seems totally fine to use two stages of whitening filters for ETMX.

We can set things up like this (changes in bold font):

The filter gains for the high power oscillator monitoring diodes were switched back from 1 to their
old values that were recorded under
20599




Jason/Peter

The IOC for h1cam18 was not running properly, an old image was being displayed and centroid values were frozen.  Tried restarting the IOC, it didn't clear the problem.  Tried rebooting h1digivideo1, it came back OK, but the IOC for h1cam18 wouldn't run.  Tried deleting all of camera 18's log files and restarting, still wouldn't run.  Logged on to network switch to power cycle the h1cam18, then restarted the IOC and it appears to be behaving OK now.

Multiple LASER trips are evident in the trends. Also, apparently, H1:PSL-OSC_DB3_CUR is reporting 100A. This is inconsistent and virtually impossible. Something wrong with the channel. FRS# 5955 filed.

Came in to find that the laser had tripped.  Error messages were as before.  Found that although I could
reset the laser I could not turn it on without rebooting the Beckhoff computer.  All the TwinCAT channels
were live and so on.  When the command was issued to turn on the pump diodes, the pump diode current(s)
did not increase.

    The crystal chiller displays "Error Flow - sensor 1", as before, even though the laser is up and
running.

    One other observation is that the mouse on the Beckhoff computer appears to be dead.  Whilst its LED
is on, moving the mouse does not move the cursor.  Not sure that the two problems are related but it
certainly doesn't help.

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.

[Matt, Carl]

The phase lock loop is now installed as an optional tool in the PI armory. I have used the settings and method Matt demonstrated to me on the test stand to lock onto OMC PI signals in the last 50W lock. I tried locking onto QPD signals but was unable to at quiescent amplitudes. The phase locked loop in the locked state is shown in the first image. It is tracking a 15521Hz ITMX mode (sorry for the poor labeling in the figure, there's still a few bugs in medm screens).

The settings used were:
Filter I - 100Hz LP Gain 1
Filter Q - 100Hz LP Gain 1
Freq Filter 1 - gain 1
Freq Filter 2 – gain 0.02, 20mHz integrator + low pass see below
FC Count - 10mHz low pass (this was not low enough as the frequency estimate was still fluctuating by 20Hz
Ampl Filt er - 1Hz low pass gain 1
Lock Filter - 1Hz low pass gain 1

Lock was acquired by setting a set frequency close to the mode frequency observed in a spectrum of the OMC HF channels. The loop was engaged with a 100Hz low-pass in Freq Filter 2 then put in a narrow band mode by engaging a 1Hz low-pass in Freq Filter 2, the loop lost lock when I tried to further reduce its bandwidth by either reducing the gain of decreasing the frequency of the low-pass. The figure is in the high bandwidth mode.  The PLL and iwave can be accessed from the mode block for any mode and a matrix is used to select a control signal, see the second image.

We had a lockloss at 50W due to what looked like the ISS 3rd loop, so I re-measured with higher recycling gain.  It seems that when we recover recycling gain by moving the PRM, we get some loop interactions that reduce the gain of the 3rd loop right where we need it.  So far, just increasing the gain of the loop has been enough to keep things under control.

Attached is a set of measurements of the 3rd loop, with the state of the IFO noted in the magnitude legend on the upper left.  "g" refers to the gain H1:PSL-ISS_TR_GAIN. 

Once, while the 3rd loop gain was -1.5, it started to oscillate.  I put the gain to -2, then down to -1.  I think it liked -1 better at that time, and that's how I left it for the rest of that lock, but -2 could also have been okay perhaps.  I'm not totally sure.  Perhaps we need to give this thing a UGF servo?

Will make log entry when leaving.  

Also, BSC8 annulus ion pump railed again, same as back in May.  See also, https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=27325 and https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=27385 

Will likely replace pump during Tuesday Maintenance period

[Jenne, Carl, Terra]

To facilitate the damping of the 18kHz ETMX mode, we are currently locked at 50W using ETMY so that ETMX can be swapped to its low noise driver. SRM dither loop is open.

To do this, it's okay to (once IncreasePower is finished) go to Manual mode and select LowNoise_ESD_ETMY. Last week we lost lock trying to do this because this state also (used to) switch the L2 coil drivers to their low noise state, which we aren't ready for.  So, the noise is acceptable for the lownoise ESDs, but not the low noise L2 drivers.  On the to-do list is to decide where in the sequence to put the L2 switching.

PI and other work is ongoing.

Kiwamu, Carl, Terra

18041 Hz (ETMY) successfully damped through several locks. 15542 Hz (ETMX) unstable after about 1 hour at 50 W but we cannot damp without going to LOWNOISE_ESD_ETMY.

We had a few ~1 hour locks at 50 W today, with a bit of time at 60 W. 

18041: damped first with +30 phase, +30K gain but rang up in the second lock despite. Changing to zero phase damped it in the second lock and prevented any ring up during the third lock.

15542: rings up almost immediately at 60 W. Rings up after an hourish at 50 W. This mode belongs to ETMX but we've been sitting at INCREASE_POWER during locks so we cannot use the LNLV ETMX driver to damp. 

Executive summary: 

* Good news - as expected, the 16-Hz comb due to the OMC length dither is gone (at least at this sensitivity level)
* Bad news - low-frequency 1-Hz combs remain, and some new low-frequency combs & lines have appeared 

Some details:

 I initially looked at 15 hours of 30-minute FScan DELTAL_EXTERNAL SFTs (30 SFTs) generated during ER9 and was aghast at how bad the low-frequency spectrum looked, with a pervasive 0.485308-Hz comb ranging up to its 446th harmonic at 216.4 Hz, but when I exclude the three hours of SFTs when the 2-second ALS- glitches were present, things don't look quite so bad (see figure 1 for a sample without removal and figure 4 with removal). I dewhiten according to the new 6-pole / 6-zero, 0.3 / 30 Hz algorithm.
 The infamous 16-Hz comb due to the OMC length dither tracked down and killed here is gone (at least at this sensitivity level and these SFT statistics). As a result the high-frequency band (up to 2 kHz) is remarkably smooth with only violin modes and sporadic isolated artifacts.
 The 1-Hz comb with 0.5-Hz offset remains pervasive, but other prior 1-Hz or near-1-Hz combs with different offsets (e.g., 0.25 Hz) are not strong.
 On the other hand, there is a new near-1-Hz comb (0.996798-Hz spacing) visible to its 204th harmonic at ~203.3 Hz.
 There is also a new near-2-Hz comb (1.999951-Hz spacing) visible on approximate odd-integer-Hz frequencies, starting from ~9 Hz and visible up to ~175 Hz. This is likely the same 2-Hz comb reported in May by Bryn Pearlstone (which Ansel Neunzert kindly reminded me about today). 
 There is a "new" 56.8406-Hz comb visible to its 11th harmonic at ~625.25 Hz, which in hindsight I can see was buried in the O1 spectrum (I overlooked the pattern and indicated the teeth as isolated lines). This time the pattern was strong enough to jump out at me and to jog my memory that this comb was seen in  H2 1-arm data in 2012 in both the arm feedback channel and a quiet sensor-noise-dominated OSEM channel. This seemed to indicate a DAQ system problem at the time. I can see from O1 NoEMi line lists that this comb is pervasive in ISI, SUS and PEM channels at the corner station and both end stations.
 The old "K" comb-on-comb (0.088425-Hz fine comb attached to teeth of a coarse 76.3235-Hz comb) has more 11 more fine teeth visible on the lowest-frequency coarse-tooth comb.
 The old calibration line at 35.9 Hz has been moved to 35.3 Hz. The new excitation lines at 33.7 and 34.7 Hz are easily visible, but not as strong as the primary calibration lines. I found these changes documented here.
 There are sporadic new isolated lines here and there (indicated in line list - see below)
 There is a "crab-killer" broad bump centered at about 58.6 Hz which degrades sensitivity in the Crab Pulsar band of interest (~59.3 Hz). On the other hand, the whole noise floor is elevated w.r.t. O1, anyway. So it may be premature to worry about the bump.


Figure 1 - spectrum for 50-100 Hz when the 3-hour 2-second-glitches stretch is included (~0.5 Hz lines marked with 'h' for 'half')
Figure 2 - 0-2000 Hz (removing 3-hour bad stretch from here on)
Figure 3 - 20-50 Hz sub-band 
Figure 4 - 50-100 Hz sub-band 
Figure 5 - 100-200 Hz sub-band
Figure 6 - 1300-1400 Hz sub-band (illustration of how clean the high-frequency band is)

Also attached are a larger set of zipped sub-band spectra and a lines list (excluding the bad 3-hour stretch). Note that because the statistics here are two orders of magnitude smaller than used for the full O1 run report, I am not yet removing lines seen then that may yet re-emerge with more accumulated post-O1 data. So many of the line labels in these figures are buried in the noise fuzz for now.

Line label codes in figures:

b - Bounce mode (quad suspension)
r - Roll mode (quad suspension)
Q - Quad violin mode and harmonics
B - Beam splitter violin mode and harmonics
C - Calibration lines
M - Power mains (60 HZ)
O - 1-Hz comb (0.5-Hz offset)
o - weaker 1-Hz and near-1-Hz combs (various offsets, including zero)
H - 99.9989-Hz comb
J - 31.4127 and 31.4149-Hz combs
K - 0.088425-Hz comb-on-comb
t - 1.999951-Hz, 2.07412-Hz and 2.07423-Hz combs
D - 56.8406-Hz comb
x - single line (not all singlets in the vicinity of quad violin modes are marked, given the known upconversion)