On Friday Daniel disconnected the 45MHz cable from the patch panel in the CER.  While reconnecting we notice that the barrel would spin as we tightened the cable.  The 45MHz had excess noise come and go.  Today we replaced the barrel in the hopes of fixing this problem.  Only time will tell.

State of H1:  locked and got beyond CARM_5PM, lost lock around engaging ASC

Activities: (no times, list was on OPS which froze, so I had to restart)

• Christina to EX
• ChrisS to EY
• Gerardo to MY, EY
• ChrisS to LVEA
• Gerardo to LVEA
• Betsy to LVEA
• Fil, Richard, to ECR
• Peter to PSL racks
• Jason to PSL racks
• PSL laser restarted
• Peter gave the ok on the PSL
• relocking started around 18:30UTC

Current:

• Roll modes rung up, changing gains to damp, waiting in ROLE MODE DAMPING

Today:  

• PSL work
• other parasitic work that requires access to buildings
• WP6230 - fil, richard - replace bulkhead N connector for 45MHz RF - done
• WP6233 - CDS - jonathan - reconfig epics

Tomrrow's Maintenance:

• SEI - model updates - WP6227, WP6217
• TCS - model update, DAQ restart - WP 6229
• Site - septic tank maintenance - WP6226
• Pcal - measurements - EY - EY will be laser hazard - WP6228
• GDS - updates - WP6231
• CDS - new daqd frame writer - WP6232

In addition to the BruCo scans for SRCL/MICH/PRCL error signals, the attached plot shows the coherence of the three auxiliary longitudinal error signals with the DBB jitter signals. There is some coherence, mostly below 30 Hz, but not much.

I have increased the heat by 1 stage in Zone 2B in the LVEA. 

State of H1: laser is off

Summary of Weekend issues:

• alog 30328 - locking but can't get past DRMI to ENGAGE_ASC
• alog 30335 - something happened to the PMC
• alog 30347 - plot showing drop in all signals coming from the PMC, but not PMC REFL
• alog 30348 - signals in DBB are changing - deviations of 0-8, though not sure if that's power in Watts
• alog 30349 - laser trip data
• alog 30351 - Beckhoff issues?
• alog 30353 - electronic "dummy" installed on PSL plumbing
• alog 30356 - PSL servos - some ok, some not
• alog 30360 - laser trips - diagnostics on chiller flow
• Saturday, laser trips 3 times during day shift, and during the night after swing shift
• Sunday, laser trips at least 3 times

The weekend has not been good for the laser and I didn’t get to investigate the coupling at HAM2 more, complete the PEM injections I wanted to make, or even look through the viewport. I attach a plot from Friday’s work showing that shaking by about a factor of 10 at HAM2 produces a couple of features 3 or 4 times above the DARM noise floor. The second figure shows the results of heavy shaking.

03:35 UTC Connecting to ~100,000 channels from conlog-test-master.

Corey has cancelled Ed's owl shift and the rest of mine.

23:04 UTC reset HAM2 HEPI watchdog
23:08 UTC reset HAM2 ISI watchdog
23:12 UTC MC locked. Leaving in down state for Robert.
23:19 UTC PSL tripped off.
23:20 UTC Peter to LVEA to remove PSL test equipment
23:27 UTC Peter back
23:30 UTC Peter back to LVEA
23:32 UTC Peter back
23:40 UTC reset noise eater
23:47 UTC taking power to 50W with just IMC locked for Robert.
23:53 UTC Taking power back to 2W
23:54 UTC Attempting to lock
00:23 UTC PRMI not locking. Starting initial alignment.
00:50 UTC Initial alignment done.
00:53 UTC ETMs are misaligned. Taking input power to 50W for Robert.
01:12 UTC Back to 2W. Attempting to lock.
01:28 UTC reset noise eater
01:39 UTC reset noise eater, back to CHECK_IR
01:51 UTC locked on PRMI, adjusted BS and PRM. PRMI to DRMI transition held, but signals in striptool very ratty. Lost lock on TURN_ON_BS_STAGE2.
Not making it through DRMI locked. I'm suspecting the ISS is oscillating.
02:38 UTC PSL tripped off. Just when I got the ISS and FSS relocked (had to turn random knobs and reset the noise eater a number of times).

The laser tripped out again.  Attached are two plots of the flow rate signals around the time of the trip.
Bear in mind that the minimum head flow rate was set to 0.5 lpm.  The flow rate for head 4 had a small
excursion close to 0.5 lpm.  Zooming in on the low point shows the flow rate to be above this limit.
It might be that the flow rate may have dipped below this level faster than the sampling time between
TwinCAT/OPC and EPICS.

    Assuming that the flow rate in head 4 did not trip the laser out, then the problem lies with the
crystal chiller.  Not sure why at this stage.  One thing to try the next time is to swap where the
chiller(s) get their 3-phase power, ie interchange where the crystal chiller plugs in to where the
diode chiller plugs in and vice versa.  The chiller is relatively new, so it's hard to believe that there's
something wrong with it but at this point everything points in that direction - in my opinion.

    Most of the laser trips have been associated with the crystal chiller.  Even with the previous two
chillers that were used.  The only thing we did not change was where the crystal chiller was plugged in.
Swapping its power socket with the diode chiller might fix the problem or switch the problem over to the
diode chiller.

    The "electronic" flow sensors have been removed and the flow rate values have been forced within
TwinCAT.

    Should the laser trip out again, please do not bring it back.

Attached are the head flows for the past 2 hours.

state of H1:  IMC was lockednow unlocked

Help: Jason, Peter

Ditails:

• laser tripped last night
• I restarted with Jason's help
• I filled both chillers with about 100ml
• Peter was on site when I returned to the CR
• the laser tripped out again
• Peter restarted and went into the PSL to realign
• IMC locked about 30 minutes ago and has stayed locked
• NPRO_NoiseEater is complaining that it's out of range
• diffracted power is coming up on DIAG_MAIN as HIGH at 6%
• Peter is going out to fix
• Robert tripped MC3 with shaking, IMC is out of lock

Should the laser trip off later on this evening, please do not attempt to bring it back.
There are a couple of things that are cobbled in that I would like removed before the laser is
restored.

The pre-modecleaner had some problems re-acquiring after the last laser trip.  The symptoms were that one could
see resonant flashes but the servo never really grabbed.  The pre-modecleaner high voltage signal instead of
looking like a ramp signal, looked like three parallel lines which is probably indicative of the high voltage
oscillating.  This is also an indication that the beam is not well centred on the locking photodiode.

    I re-aligned the beam both into the pre-modecleaner and onto the locking photodiode.  Unlocked the DC output
was ~1V.  Locked, ~0.26V.  Crudely that's a visibility of 74% with the ISS off.  That is consistent with the
power throughput of the pre-modecleaner as calculated from the values displayed on the MEDM screen.

    In bring the FSS back up using the autolocker, I noticed that the common gain kept going between 0, 2 and
16 dB even though the autolocker status did not indicate the gain was being ramped.  I assume this was guardian
doing its thing.

    The ISS however seems to be exhibiting signs of one of the switches being touchy because turning the loop
on/off at times seems to have no effect.  Unless, of course, the corresponding DAC channel is intermittent.

  Hamlet 1.4

Something happened early in the morning today (about 2016-10-08 12:50 UTC +- 10 min) and the transmission is only 78W as of now while the reflection is 38W or so.

Evan, Daniel

17:12:30 UTC Oct 7 2016:

• RF modulation off for 9 and 45 MHz
• 45 dB whitening gain compensated by a filter gain of 0.0056
• 1 stage of whitening, compensated
• V/ct filter engaged, referred to TNC ouptut of 2-chn demod board
• Dark

17:16:30 UTC Oct 7 2016:

• same input configuration
• 29 mA of photocurrent

17:18:30 UTC Oct 7 2016:

• turn DC centering of REFL WFS on

17:24:30 UTC Oct 7 2016:

• turn DC centering off again
• 14.8 mA of photocurrent

17:32:00 UTC Oct 7 2016:

• 9 MHz modulation on
• 14.8 mA of photocurrent
• DC values: 9I = 3.7 mV; 9Q = 9.5mV

17:34:30 UTC Oct 7 2016:

• 9 MHz modulation on
• 29 mA of photocurrent
• DC values: 9I = +7.2 mV; 9Q = +18.1mV

18:06:30 UTC Oct 7 2016:

• 9 MHz and 45 MHz modulation on
• 29 mA of photocurrent
• DC values: 45I = –14.3 mV; 45Q = +62 mV