I will clear this when we are not in Observing, as we currently are and with double coincidence.

Kyle, Gerardo 

Today we applied Ultratape against the spool and both sides of the stiffener around the entire periphery, in effect, bagging the inaccessible space between the stiffener ring and the spool.  Next, we made a small incision and inserted a 1/4" poly tube to allow us to pump the inside of this "tape bag".  The overall seal wasn't very effective due to the lack of access in the area of interest - between the spool and the support gusset which is also the area of the leak - but we were able to achieve < 300 torr inside the tape bag.  As expected, the Y-mid pressure responded accordingly.  

So, at this point we have the leak location narrowed down to approx. 1" x 3" at the overlap of the spool seam weld and stiffener stitch weld (poor fabrication technique!)  We have some ideas of how to better access this area which we will need to do before applying epoxy or equivalent to seal the leak.  

Laser Status:
SysStat is good
Front End power is 32.13W (should be around 30 W)
Frontend Watch is GREEN
HPO Watch is RED

PMC:
It has been locked 11.0 days, 20.0 hr 27.0 minutes (should be days/weeks)
Reflected power is 1.917Watts and PowerSum = 25.65Watts.

FSS:
It has been locked for 0.0 days 3.0 h and 30.0 min (should be days/weeks)
TPD[V] = 1.512V (min 0.9V)

ISS:
The diffracted power is around 9.125% (should be 5-9%)
Last saturation event was 0.0 days 3.0 hours and 30.0 minutes ago (should be days/weeks)

Things to note:

The usual LRA out of range andVB program online warngins are red on SYSSTAT.adl
 

O1 days 29, 30, 31

model restarts logged for Sun 18/Oct/2015 No restarts reported

model restarts logged for Sat 17/Oct/2015 No restarts reported

model restarts logged for Fri 16/Oct/2015 No restarts reported

TITLE: 10/19 [DAY Shift]: 15:00-23:00 UTC (08:00-16:00 PDT), all times posted in UTC
STATE Of H1: Locked. Observing @ ~76 MPc.
SHIFT SUMMARY: Recovered easily from single lock loss. No apparent corresponding seismic cause. Evan and Sheila took time after recovery to work on measurements at ISCT6. Kyle and Gerardo working on leak checking at mid Y. Joe and Chris working on sealing concrete enclosure over X arm. Kiwamu fixed SDF value for H1:PSL-ISS_SECONDLOOP_SIGNAL. 
INCOMING OPERATOR: TJ
ACTIVITY LOG:

15:02 UTC Jeff B. checking TCS chillers in mechanical building
15:16 UTC Jeff B. back
15:20 UTC Crew heading out to work on X arm concrete enclosure approximately four doors past mid X.
17:10 - 17:17 UTC Stepped out of control room
~18:39 UTC Corey in control room giving tour to two people
19:28 - 19:48 UTC Stepped out of control room
20:11 UTC Kyle getting part out of LVEA
20:21 UTC Kyle back, reports light is on in room immediately after card reader
20:25 Evan and Sheila moving computer from PSL racks to ISTC 6
20:33 UTC Joe driving up X arm to work on beam tube sealing
20:54 UTC Betsy to LVEA to turn on CDS wifi for Evan and Sheila
20:55 UTC Kyle and Gerardo to mid Y for leak checking
21:11 UTC Betsy to LVEA to check on wifi/issue logging into computer
21:18 UTC Betsy back
21:29 UTC Evan and Sheila done
~21:52 UTC Kyle and Gerardo back
22:02 UTC Kyle and Gerardo heading back to mid Y
22:15 UTC Joe back from beam tube enclosure, Chris still there.
22:31 UTC John to mid Y to join Kyle and Gerardo

Attached is the whiteboard plan for tomorrow's Tuesday Maintenance period.  Basically, we'll drop the lock first thing in order to misalign ETMs for an SRY characterization study, then roll through some ISS 2nd loop characterization.  As shown on the whiteboard, people needing to go to the end stations should do so which the SRY study is going such that End station charge measurements can go on unadultured.  After all of this, relocking will resume and commissioners will spend some time on jitter and upconversion studies.  See picture for additional scheduled tasks.

• Title: 10/19 OWL Shift: 23:00-7:00UTC (16:00-0:00PDT), all times posted in UTC
  

• State of H1: Observation Mode at 75Mpc for the last 2+ hrs
  

• Outgoing Operator:  Patrick

• Quick Summary: He had one lockloss, but brought it up right after that and has ben locked since. CW inj are on, wind is 15mph or below, useism ~0.1um/s.

Summary--Looks like both HAM2 and the ITMY STSs (STSA & B) have problems with their Y and X dofs respectively.  The HAM5 unit is the one solid sensor but I wonder what it will look like if we moved it.  Of course it would be that Robert believes the ITMY location in the BierGarten is the ideal place most free from tilt affects.  The End sensors look okay but this is not a great way to compare.  We need a good unit to move closer for comparison.  We still have a unit at quanterra.  Further, I'll seek out Robert's review for better scrutiny.

More detail:

Looking at the upper left graph, ASD of the Y dofs: Ham2 Y has elevated noise (WRT other units) from 3 down to 0.4 hz.  It is also noisier below 90 mhz, I don't think that is tilt, others would suffer as well I'd think if it was.

At the lower left graph, the Y dof coherences further suggest Ham2 is under performing.  The end station units coherence gets above 0.8 below 100mhz and thereafter follows the like coherence between ITMY & Ham5.  That seems reasonable.

The middle column of plots for the X dofs suggests that the ITMY unit is not as healthy as the HAM2 or HAM5 around 100 to 300mhz.  HAM2 looks much better for the X dof than the Y dof.  The Ends X dof behaves much like the Y dof.

For the Z dof in the third column, while nothing jumps out in the spectra, the reduced coherence for the red & blue relative to the green trace suggests the ITMY Z is mildly ill.  For the end stations in Z, it looks like tilt is plaguing things below 40mhz but this data is from 2am this morning and was not subject to much wind...So I'm not sure what to suggest there...

Evan and Sheila done
Ran a2l script again

Adjusted ETMX in pitch and yaw to lock X arm on green
Adjusted PSL diffracted power from 5.8% to 8.5% by changing REFSIGNAL from -2.00 V to -1.98 V.
Ran a2l script.

Holding off on going to observing mode to allow Sheila and Evan to perform scattering measurements on ISTC6. (WP 5566)
Also tracking down SDF diff for H1:PSL-ISS_SECONDLOOP_SIGNAL. The setpoint has F10 ON and it is OFF.

Cause yet unknown.

SUS I_T_M_Y saturating (Oct 19 20:07:54 UTC)
SUS M_C_2 saturating (Oct 19 20:07:54 UTC)
SUS S_R_M saturating (Oct 19 20:07:54 UTC)
DRMI Unlocked (Oct 19 20:07:54 UTC)
Intention Bit: Commissioning (Oct 19 20:07:54 UTC)
ISC_LOCK state: DOWN (Oct 19 20:08:05 UTC)
SUS OMC SW watch dog tripped (Oct 19 20:08:16 UTC)

Still locked in observing at ~ 77 MPc. No changes in state.

15:02 UTC Jeff B. checking TCS chillers in mechanical building
15:16 UTC Jeff B. back
15:20 UTC Crew heading out to work on X arm concrete enclosure approximately four doors past mid X.
17:10 - 17:17 UTC Stepped out of control room
~18:39 UTC Corey in control room giving tour to two people

SudarshanK, TravisS

Travis and Darkhan took Pcal calibration measurements at the end station last week (alog 22489). Using the gps time information from that alog we have calculated the new pcal calibration factors. The summary is that the calibration at Y-End is pretty close to what we measure last time (Aug 27) however, the calibration at X-end, atleast for RxPD, has changed significantly due to clipping of one of the pcal beam. The clipping issue at X-end is discussed in detail on another recent alog by Rick (alog 22529).

Attached is the calibration factors from each endstation compared to the most recent calibration. This report includes the parameters used and relevant intermediate numbers as well. A summarized report of the final calibration numbers is uploaded to the DCC document (T1500252). The calculation of TxPD factor and its uncertainty on X-end will have to be done little differently in light of the clipping issue. For now, I just reported what is calculated by the old code but I will work on implementing a more accurate representation.

As part of Wednesday's commissioning excercises, we looked at the coupling of input jitter into DARM.

I injected band-limited white noise into IM3 pitch (and then IM3 yaw) until I saw a rise in the noise floor of DARM.

We can use the IM4 QPD as an estimate of the amount of jitter on the interferometer's S port. On the AS port side, we can use the OMC QPDs as an estimate of the AS port jitter, and DCPD sum indicates the amount of S port jitter coupling into DARM.

One thing of note is that the jitter coupling from IM3 to DARM is mostly linear, and more or less flat from 30 to 200 Hz:

• For the pitch excitation, at 100 Hz the IM4 pitch ASD was 3.1×10⁻⁷ ct/rtHz, the measured TF was 1.0 mA/ct, and the observed IM3-induced DARM noise was sqrt[3.7² − 1.7²]×10⁻⁷ mA/rtHz = 3.3×10⁻⁷ mA/rtHz. Numbers hang together.
• For the yaw excitation, at 100 Hz the IM4 yaw ASD was 1.6×10⁻⁷ ct/rtHz, the measured TF was 5 mA/ct, and the observed IM3-induced DARM noise was sqrt[8.2² − 1.7²]×10⁻⁷ mA/rtHz = 8.0×10⁻⁷ mA/rtHz. Numbers hang together.

The upper limit on IM3 jitter that one can place using the IM4 QPD seems to be weak. At 40 Hz, projecting the quiescent level of the IM4 yaw signal to the DCPD sum suggests a jitter noise of 2×10⁻⁷ mA/rtHz, but this is obviously not supported by the (essentially zero) coherence between IM4 yaw and DCPD sum during low-noise lock. Of course, this does not rule out a nonlinear coupling.

As for AS port jitter, the coupling is seen more strongly in OMC QPD B than OMC QPD A.

The LHO SEI team has known about a .6-ish hz peak on the HAM3 ISI for a long time (see my alog 15565, December of last year for the start, Hugh has a summary of LHO alogs in the SEI log for more). I was working with Ed on a DTT template for the operators when I noticed it was now gone. Very strange. Looking a little closer, it seems to have been decreasing over the last couple of days to a week, and disappeared completely this morning about 7-8:00 UTC. Attached spectra are from ~0:00 UTC (red) and ~16:00 UTC (blue, when I found it was missing). Looking at random times over the last week, it looks like it may have been trending down.

Could someone in Detchar look at this peaks longish term BLRMS, say over the last month, or even over the last year since we found it? Pretty much every sensor in that chamber saw this, but the GS-13s are the best witness.