Activities:

• EY: reboot, cleaning
• CS: SQZ, PSL, HAM6, cleanroom move, leak checks
• EX: optic pictures, prep for welding, field meter

Details:

• 16-04-18 16:31 JeffB to LVEA to transition to laser safe
• 16-04-18 16:33 MarkD and Tyler to EX - staging for EX work
• 16-04-18 16:51 Chandra to LVEA to leak check
• 16-04-18 16:56 Shiela to optics lab
• 16-04-18 16:59 Nutsinee to SQR table
• 16-04-18 17:00 Kyle turning on cleanroom at EX
• 16-04-18 17:01 APS starting at LSB, then to Staging Building
• 16-04-18 17:01 Terry to SQR-HAM6 tables
• 16-04-18 17:06 JeffK and TJ to HAM6 in-chamber work
• 16-04-18 17:23 Jason and JeffB to PSL
• 16-04-18 17:29 Shiela done in optics lab
• 16-04-18 17:33 PeterK to PSL
• 16-04-18 17:38 Ed to the PSL
• 16-04-18 17:51 Rick to the PSL for PMC swap
• 16-04-18 17:56 Karen leaving EY
• 16-04-18 18:04 Travis and Betsy to EX to take pictures
• 16-04-18 18:22 Tyler and MarkD done at EX - heading into LVEA to prep for cleanroom move
• 16-04-18 19:02 DaveB to EY to reset SEI
• 16-04-18 19:09 Olivia, Craig, Niko, EX to work with the field meter
• 16-04-18 19:27 Ed out of PSL
• 16-04-18 19:56 Terry out of LVEA
• 16-04-18 19:57 MarkD and Tyler out of the LVEA
• 16-04-18 19:57 JeffK and TJ out of the LVEA
• 16-04-18 19:58 Bubba and Gerardo to LVEA to move cleanroom

J. Kissel, T. Shaffer

Replacing S/N 551 (bad) with S/N 553 (hopefully good).

New open light current value:
29106

OSEMINF OFFSET = -14553
OSEMINF GAIN = 1.0307

Daniel changed some internal wiring in h1sqz. Model was restarted, no DAQ restart needed.

F. Clara, J. Kissel, T. Shaffer

We're back at the SUS OPO, trying to solve the last problem -- that the V2 OSEM shows a poor frequency response above its resonances (41256) that appeared between Feb 2018-02-27 and 2018-03-29. Because the poor frequency response has the same shape as the well-known sensor-to-actuator electronics coupling -- high-Q zero at 10-20 Hz -- (a.k.a. high frequency turn-ups a. la IIET Ticket 478040536 and 40613).

The below set of tests has convinced us that the H1 SUS OPO V2 AOSEM needs to be replaced, so we'll do that this afternoon.

We've therefore conducted several electronics tests this morning:
    - Ran the standard "ground loop" checks for shorting of the readout-chain's shield to ground: disconnected the H1V1H2V2 DB25 pin cable on the back of the US satamp, plugged a DB25 pin breakout board into the cable, then
        - Check for any short of pins to chamber ground: 
             - run a lead from the closest chamber (in this we clipped to a bolt on one of the viewport blanks on the HAM5 side of the MCB Output Beam Tube between HAM4 / HAM5) into the Return (black) of the DVM
             - and check for continuity between any of the 25 pins and chamber ground. 
             - There shouldn't be any continuity, and we found none.
        - Restoring the standard (black) lead into the Return of the DVM, check that pin 13 is continuous with the shield of the cable, and no other pin is continuous with ground. Only pin 13 should be continuous with the cable shield, that was true.
        - Check that no pin is unintentionally/unexpected continuous with any other pin. For this OSEM cable fed into a US Satellite Amplifier (D1002818), we expect pins 1 & 14, 4 & 17, 7 & 20, 10 & 23 to have low resistance because these connect the positive to negative legs of the OSEM coil (namely ~19 ohms). However, no other pins should be continuous with each other. We found all this to be true.

    - Scoured the in-chamber readout cabling, looking for potential electrical grounding between the readout cable and the ISI or chamber walls. We found nothing obviously suspicious, and no change in frequency response after several moves.

    - TJ physically disconnected the micro-D connector of the Quadropus (D1000239) from V2 OSEM at the OSEM, then re-seated and re-tightened the connection. No change in response.

    - TJ physically disconnected the DB25 connector of the Quadropus from the Table Cable Bracket (D1001346), then re-seated and re-tighted the connection. 
    - TJ found that one of the screws securing the flexi-circuit (D0901252) to the V2 AOSEM assembly (D0901065) was loose, so he tightened it.
        After these two changes test, we saw a significant increase in the zero frequency
    - Further tightening and loosening of the AOSEM's flexi-circuit screws continued to have an effect on the zero frequency, namely tighter made it *better* but not perfect like all other OSEMs.

    - As a final nail on the coffin of the flexi-circuit of the V2 OSEM, we swapped micro-D connectors of the Quadropus cables between H2 and V2, and readout each the OSEM with the opposing signal chain -- taking a transfer function of V2 with the H2 electronics chain, and of H2 OSEM with the V2 electronics chain. 
        V2's electronics chain reading out H2 showed an entirely normal high-frequency response [first attachment]. H2's electronics reading out V2 showed a similar bad response [second attachment].
        
Attachment Key:
[first attachment]   
    - black : Perfect (in-vacuum), fully functional reference from L1 SUS OPO
    - magenta : Before today, clearly identified badness (high-frequency zero) with V2 electronics reading out V2 OSEM.
    - red : Fully functional, today, with V2 electronics reading out H2 OSEM. final nail in the coffin

[second attachment]
    - black : Perfect (in vacuum), fully functional reference from L1 SUS OPO 
    - blue :  H2 electronics reading out V2 OSEM Still bad, final nail in the coffin
    - magenta : Before today, clearly identified badness (high-frequency zero) with V2 electronics reading out V2 OSEM.
    - red : During today, after tightening flexi-circuit screw.

A significant roll of the ETM optic is apparent in the attached photos, which corresponds to the fibers breaking on one side of the optic.  We used the welding mass jack to lift the mass off of the compressed viton EQ stops and to unload the remaining two fibers such that if they are compromised they would not catastrophically break.  I would estimate that not more than 1-2 mm was required to fully unload and slacken the remaining fibers, indicating that they were already almost completely unloaded after the break. 

The photo of the wipe shows a piece of metal particulate found on the lower structure and gives you an idea of the size and nature of particulate commonly found around the Quad as a result of the assembly/disassembly procedure.  

To get h1seiey running again I rebooted it using the front-panel-reset button. This in turn caused a dolphin glitch of h1susey and h1iscey. I rebooted h1iscey because it had an uptime of 211 days, I just restarted all the models on h1susey (it has an uptime of 38 days).

Laser Status:
SysStat is good
Front End Power is 0.0003016W (should be around 30 W)
HPO Output Power is 0.7154W
Front End Watch is GREEN
HPO Watch is RED

PMC:
It has been locked 2 days, 18 hr 26 minutes (should be days/weeks)
Reflected power = 20.46Watts
Transmitted power = 42.4Watts
PowerSum = 62.87Watts.

FSS:
It has been locked for 2 days 23 hr and 39 min (should be days/weeks)
TPD[V] = 2.293V (min 0.9V)

ISS:
The diffracted power is around 0.13% (should be 3-5%)
Last saturation event was 0 days 3 hours and 43 minutes ago (should be days/weeks)

Possible Issues: (all accounted for, due to PSL commissioning)
Front End Power is Low
PMC reflected power is high
ISS diffracted power is Low
LRA out of range, see SYSSTAT.adl

Comparing to past plots, signals at EY are consistent with it being unlocked, signals at EX are consistent with it being locked, and Corner Station HEPIs pressures are consistent with being unlocked, which matches the information from the medms, so no  issues.

Morning Meeting:

• Jeff Jones started today
• APS contractor for access system starts install today, any questions, call Richard
• a considerable number of Front Ends require rebooting, which is planned for this week

CS:

• HAM6: JeffK and TJ on VOPO alignment
• SQZ: Terry, Sheila, Nutsinee, activities around HAM6
• HAM6/SQZ: TVo, Sheila, OMC alignment loops closed yesterday
• VAC: Chandra, Bubba, crew, moving IMC cleanroom, requires craning, laser safe
• SR2 CO2 laser: still residing in the SQR bay, no im
• PSL: Jason, Peter, mode matching to the PMC
• PSL: Jason, Peter, Rick, PMC swap planned for sometime in the next 1-2 weeks
• EOM: Sigg, Sheila, RF needs attention, unknown timeframe
• LVEA: transitioning to Laser Safe in the AM, back to laser hazard later today

EY:

• ALS:  Richard, Fil, work continues
• SUS: JeffK has measured bounce and roll
• ALS and PCAL: plan to turn green and pcal beams on, sometime next couple weeks

EX:

• SUS: Travis, Tyler, MarkD, staging for EX repairs
• PEM: Olivia, others, field measurements continue, instrument is in the chamber, access into the chamber is periodic
• VAC: Chandra, crew, turbo pump valve and IP12 valve swap, requires some craning

• IMC is unlocked
• PSL FSS and ISS are locked
• front end issues, see Dave's alog, Jaimie's alog
• VerbalAlarms will not run without connecting to channels at EY that are currently unavailable
• wind has bee over 40mph for the last 3 hours, and currently the wind is between 15mph and 45mpg

As has been reported in previous alogs, the 2.6.34 kernel has a timer counter overflow bug with makes the machines susceptible to freeze-up if they have been running in excess of 208.5 days. Last week h1build froze, and this weekend h1seiey, h1susauxb123 and h1susauxh34 did the same. The machines marked with an asterix in the list below have an uptime which exceeds 208.5 and could freeze at any time.  We should work on verfifying their SDF settings are up to date and then reboot them at our earliest convenience.

* h1psl0 up 211 days

* h1seih16 up 211 days

* h1seih23 up 211 days

* h1seih45 up 211 days

* h1seib1 up 211 days

* h1seib2 up 211 days

* h1seib3 up 211 days

  h1sush2a up 58 days

  h1sush2b up 201 days

* h1sush34 up 211 days

  h1sush56 up 192 days

* h1susb123 up 211 days

* h1susauxh2 up 211 days

  h1susauxh34 up  7:01

  h1susauxh56 up 191 days

  h1susauxb123 up 7:03

  h1oaf0 up 61 days

  h1lsc0 up 58 days

  h1asc0 up 202 days

* h1pemmx up 209 days

* h1susauxey up 211 days

  h1susey up 38 days

* h1iscey up 211 days

* h1susauxex up 211 days

* h1susex up 211 days

  h1seiex up 95 days

  h1iscex up 163 days

On Friday afternoon Terry McRae and I crashed several of the ZOTAC workstations in the control room by dragging and dropping channel names from the INMONs of the OMC QPDs into the terminal.  Dave Barker tried this on his workstation and it was fine for him. 

In this situation the workstation completely froze and the solution was to ssh in from another workstation and pkill medm.  

Now I am trying to redo the dark offsets for the AS WFS, and having a similar problem.  When I try to middle click on an medm screen and drag it into the terminal, sometimes it works but it seems like about 50% of the time medm crashes.  The workstation doesn't freeze, although my dataviewer did freeze.  I cannot reopen the sitemap.  Again this is a ZOTAC workstation.

I just noticed that four front end machines are offline: h1susauxb123, h1susauxh34, h1seiey, and h1pemmy.

All models on all these machines are dead, and the machiens themselves are inaccessible via ssh.

I was hoping to do an OMC scan today and it's tantalizingly close with the angular loops closed but it seems like the both OMC_DC are saturating even though I've turned off the all the gains and whitening(de-whitening).   The attachment shows the scans going negative at 2 Watts into the IMC.

So I turned down the power into the IMC to about .1 watts and things got better but it was still very unclean scan data so I'm a little confused because Dan Hoak's OMC scan was able to handle about 4 miliamps on OMC_DCPD Sum.

I've misaligned SR2 so that the OMC isn't flashing and returned the DCPD whitening filters to their nominal observe state (1 whitening + 1 dewhitening).  Also I've turned off the OMC ASC and the AS WFS DC loop so that if the IMC loses lock the optics don't go crazy.

Today, we performed a few iterations of weld annealing with the goal of reducing the differential pitch offset of the PUM-to-ETM from the initial welded value of ~3mRad.  After 2 iterations, we had the pitch down to ~1.6 mRad.  As we were preparing to break for lunch, I noticed that the PUM prism crack (referenced in aLog 41111) seemed to have grown from what I recalled.  During the break, I looked at Betsy's pictures that were taken shortly after removal from chamber which confirmed my suspicions that the crack had increased in length.  We decided this warranted a discussion with several of the decision making staff (Dennis, Peter, Calum, Fred, and Garilynn).  Together we concluded that it was probably fine to carry on since the crack only seemed to lengthen when exposed to heat from welding (the initial cause of the crack and the cause of this case of extension) and that this side of the PUM would not need to see any more heat for the annealing that was continuing.  (Note that the copper prism shield that was designed to protect this from happening again after the first instance WAS installed, but apparently enough radiative heat was present to affect the crack anyways.)  We continued on with another iteration of annealing which resulted in a final differential pitch of ~350 µRad.  This concludes the final post-O2 monolithic welding session.  Check.