While Jason and Fil were looking at the TCSY laser, Corey had left ISC_LOCK sitting at ENGAGE_SRC_ASC. We noticed that DIAG_MAIN and the ALSX guardian were both complaining about the X-arm fiber polarization. We thought we could ignore this because the arms were no longer "on ALS", but when ISC_LOCK got to the SHUTTER_ALS state, ISC_LOCK couldn't proceed because the ALSX guardian was in fault.

To move forward, I had to take the ALSX guardian to manual and put it in the SHUTTERED state. Buuttt... now ALSX wasn't monitored by ISC_LOCK. When I got to NLN, the TCSCS was in safe (from earlier work?) and it had a bunch of differences in SDF, TCS_ITMY_CO2_PWR guardian was also complaining (where is this screen? I had to use "guardctrl medm TCS_ITMY_CO2_PWR" to launch it, it recovered after INITing), and ALSX was controlled by USER. This last one I fixed by doing a caput  "caput H1:GRD-ALS_XARM_MANAGER ISC_LOCK" . Normally, that would be fixed by initing the parent node, but for ISC_LOCK that means going through down and breaking lock.

Of course, after fixing all of that and surviving an earthquake, I lost lock due to PIs that seem to have shifted because of the TCS outage.

STUDYING RF PHASE DRIFTS IN THE H1 RF SOURCE OSCILLATOR SYSTEM IN CER:  
WORK PERMIT 6453  Dick Gustafson
TUES MAINT 1/25  1700 UTA(0900pst) to 2000 (1200pst)   at CER ISC Racks C# and C4.
Maintenance period access...

This  was motivated by a search for a cause of a 1/2 and 1 Hz comb of lines seen in long CW GW searches,
multiday integrations,  and having noticed apparent OSC phase drifts in the commissioning/shakedown era.
The scenario is the 1 PPS (1Hz) basic correction interval modulates the RF in random but sharp interval way.
A second 1 Hz theory was power modulation associated with the 1Hz on/off of perhaps a 100 LEDS
switching perhaps 1 amp in the OSC SOURCE power system; reprogramming, ie removing this 1 Hz variable 
perhaps changed, but did not eliminate the 1/2 Hz comb effect.

Results:  so far... 
We verified the 10 MHz OSC-VCO phase drifts/swings (relative to 10.000...MHz ref)  +- ~ 5 to 25 ns, 
over randomly different swing periods of ~ 4 - 30 sec.
The phase swings back an forth relative to a freq tweeked reference osc signal as seen on a TEK 3032
Oscilloscope; the ref OSC triggers scope; observations are made with MK I Eyeball.

> The phase drift seems ~ constant in two drifts speeds for  +, and - directions; 
  and swings... ie drifts of varying periods  ~ < 4  to ~30 sec.
 
The 10 MHz OSC was selected first (today) as having a freq with a convenient reference stable 
tunable oscillator units available: << .1 ns sec drift: 
a "tuneable" SRS SC-10 very stable 10.000000 MHz VCO;   and an SRS FS725 Rb87 Rubidium frequency 
standard ("atomic clock ") 10.000 MHz.  This provides a stabilized 10.00000000000 MHz reference    
very slowly tunable over very limited range.  Used here first to verify the stability and
tunability of the ref oscillators and learn subtleties.

PLAN:  We hope to devise a practical scheme to test all or most of the OSCILLATORS in the LHO CER...
       are they the "same"?  or  what?
       ..next maintenance or opportunity....to come up with a plausible Drift model
       and understand consequences. 

I have started Conlog running on conlog-master and conlog-replica. conlog-3.0.0 is running on conlog-master. conlog-flask-3.2.0 is running on conlog-replica. There are 6,653 unmonitored channels (attached). Some of these I can connect to from a CDS workstation, but not from conlog-master. I'm not certain why yet.

TITLE: 02/01 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 68Mpc
INCOMING OPERATOR: Jim
SHIFT SUMMARY:

In OBSERVING for a good part of the shift and then at 21:18utc (1:18pmPST), where we had a lockloss AND we also had the TCSy laser trip (IR Sensor).  Rest of the shift was focused on the electronics box for the TCSy.

The End Station temperatures were increased due to current & upcoming cold weather.  We will want to keep an eye on the ETMs (There are StripTools looking at the vertical M0 sensors for the ETMs on the operator0 workstation.

Final Note:  ALS Xarm polarization alarmed High while we are in holding pattern for H1.  Jim, or future operator will need to minimize this after next lockloss.

LOG:

• 21:18 Lockloss (due to TCS?)
  • Diag Main:  TCS_LASER:  Y IR alarm
  • TCSy CO2 Laser tripped OFF
  • Jason contacted & marked this for CORRECTIVE MAINTENANCE
  • Fil & Jason ended up power cycling the little elec box
  • Tweaked ETMs, TMS, BS
• ~21:18 Verbal_Alarm also crashed around lockloss time!
• 21:25-21:50 Set addresses on beckhoff terminals at ISCTEX (WP6460), while H1 down (Richard, Fil)
• 22:38 Another TCSy laser trip.  Jason & Fil are addressing it now.
• Handing over H1 in a "Holding Pattern" at ENGAGE_SRC_ASC during TCSy work.

While heading to NLN, the TCSy laser tripped again.  Fil & Jason are working on this now (& Guardian is paused).

J. Oberling, F. Clara

At around the same time as our recent lockloss, the IR Sensor alarm popped up on TCSy and would not clear.  I went out and reset the laser chassis, no luck.  I then wiggled the cables to and from the IR Sensor comparator box to no avail.  Found Fil for assistance and we set about trying to get the alarm to clear.

This is when things got a little odd.  Fil picked up the little comparator box (sits on top of the TCSy enclosure) and the alarm instantly cleared.  He set it back down again and the alarm returned.  He unplugged and reseated the cable that goes from the comparator box to the TCSy laser chassis; the alarm cleared, but then returned before we could restart the laser.  He then unplugged and reseated both connectors for the comparator box and the alarm did not come back.  We wiggled the cables and Fil tapped on the comparator box, both connectors, and the cables with a small screw driver; we could not get the alarm to return.  As it now appears to be working we decided to leave it as is; we will monitor this.  Regardless, something appears to not be quite right with this comparator box...

The CO2 laser was restarted without issue.

Owing to the colder temperatures last night and expected the next several nights, I have increased the heat at both end stations by 1ma.

John and I started up HU-2 yesterday at Y End to add some humidity to the VEA. 
In the process of starting this unit up we removed the lid on the reservoir and found that a large piece (~9" square) of bubble wrap had been left in the water discharge area of the reservoir. We removed the bubble wrap and started the humidifier. It is set at ~50% (5V on a 0-10V scale). 
The 5 day plot shows an increase in the humidity.   



Note:The 14 KW heater is powered from a electrical panel located in the VEA and was cycling several times a minute.

Starting CP3 fill. LLCV enabled. LLCV set to manual control. LLCV set to 50% open. Fill completed in 15 seconds. LLCV set back to 12.0% open.
Starting CP4 fill. LLCV enabled. LLCV set to manual control. LLCV set to 70% open. Fill completed in 106 seconds. TC A did not register fill. LLCV set back to 37.0% open.

Jason, Betsy

Yesterday during the maintenance period, Jason and I took a look at the beams coming from the ITMY and CPY in order to "map" where beams are there relative to their back scatter into the chamber in other places.  This is similar to what LLO did when they repointed their CPY mechanically in-chamber in an attempt to mitigate scatter (alog 28417).  Attached is our "map" which will eventually tie into a larger picture of scatter and "correct" pointing of CPY... TBD.  A few facts that I dug up for the record:

LHO CPY CP05 has the thin side to the +X side

LLO CPY CP03 has the thin side to the +X side

The original installation of CPY and ITMY IAS pointing (with 0,0 OSEM alignment offsets) match ~roughly were we find them now (with 0,0 OSEM alignment offset), namely the CPY pit was offset from ITMY-AR by a couple mRad.  No major drift over 2 years in alignment, although it is further out from this now by a factor of 2, not sure why.  ITMY alignment has changed though, due to commissioning/locking work over 2 years.  Recall, the original large pointing spec of the CP of "within ~1.4mRad" was for other factors such as ESD capability, and not necessarily for scatter.  We may be refining this spec now for scatter mitigation.

Our map as shown in the attached:

CPY-HR is 2.2mRad away from ITMY-AR in PITCH, while not too far off in YAW (well under a mRad).  IAS spec was ~1.4mRad, we insatlled it at ~0.9mRad.

The CPY pitch pointing could be repointed to match the ITMY-AR better which may improve scattering, although we do not currently have enough electronic range.  So this will need to be done mechanically during a vent.  We could point the CPY as far as electronically possible and re-evaluate for scatter.

(Thought I posted this earlier!)

TITLE: 02/01 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Observing at 65Mpc
OUTGOING OPERATOR: Cheryl
CURRENT ENVIRONMENT:
    Wind: 10mph Gusts, 9mph 5min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.45 μm/s

Beginning of the shift saw clear skies with a balmy 17degF temperature
QUICK SUMMARY:
Observing H1 was handed off & it has been in Observing since 15:15utc (7:15amPST).

Video3 died & was rebooted.

Ran the weekly SEI CPS checks.

BSC:

No major changes here.  Note some lines around ~50Hz for ETMy Stage1 (& took measurements at multiple times and saw it there); just a feature I wanted to note, but not a huge high frequency change---which we are supposed to watch out for according to the procedure.

HAM:

No major changes---high frequency looks mostly flat for al HAM ISIs.

Modified the output of HAM6 ion pump controller to -7.0 kV from -5.6 kV, did a re-configuration/calibration after via the front panel.

Work done under WP#6461.

PyCBC analysts, Thomas Dent, Andrew Lundgren

Investigation of some unusual and loud CBC triggers led to identifying a new set of glitches which occur a few times a day, looking like one or two cycles of extremely high-frequency scattering arches in the strain channel.  One very clear example is this omega scan (26th Jan) - see particularly LSC-REFL_A_LF_OUT_DQ and IMC-IM4_TRANS_YAW spectrograms for the scattering structure.  (Hence the possible name SPINOSAURUS, for which try Googling.)

The cause is a really strong transient excitation at around 30Hz (aka 'thud') hitting the central station, seen in many accelerometer, seismometer, HEPI, ISI and SUS channels.  We made some sound files from a selection of these channels :

• PEM-CS_SEIS_LVEA_VERTEX_Z (sped up by factor 4)
• PEM-CS_ACC_OPLEV_ITMY_X (sped up by factor 4)
• PEM-CS_ACC_BEAMTUBE_MCTUBE_Y (sped up by factor 2)

PEM microphones, interestingly, don't pick up the disturbance in most cases - so probably it is coming through the ground.

Note that the OPLEV accelerometer shows ringing at ~60-something Hz. 

Working hypothesis is that the thud is exciting some resonance/relative motion of the input optics which is causing light to be reflected off places where it shouldn't be ..

The frequency of the arches (~34 per second) would indicate that whatever is causing scattering has a motion frequency of about 17Hz (see eg https://ldvw.ligo.caltech.edu/ldvw/view?act=getImg&imgId=154054 as well as the omega scan above).

Maybe someone at the site could recognize what this is from listening to the .wav files?