Remove Dust Monitors from LVEA

 Dave Barker, Jeff Bartlett  

   Dave removed dust monitors #2, #3, #4, and #30 from the LVEA dust monitor software. These monitors have been removed from the LVEA. Currently dust monitors #5, and #6 are running to support work in HAM5/6 and dust monitor #10 is the permanent LVEA monitor in the Biergarten. 

   I will be updating the "check monitors are working" script and AlarmHandler shortly.
 
Closing WP #7277.   

Post Pump down elevation Survey of HAMs 2 & 3

On Aug 29 & 30, while at vacuum, the elevations of the HEPI piers were measured with Optical Auto-Level--LHO aLog 38584.  On Sept 20 and 27, the HAM Piers were measured again--38776 & 38810, now with the Vertex was at atmosphere.  Today, after the Vertex (sans HAM6) is again under vacuum, the piers were sighted again.

The conclusion here is while there are some changes while vented and when back to vacuum, the most is a few tenths of a millimeter and amount to ~100urads of tilt in the worst case.  Not necessarily tiny but not horrible.  Attached are my surveying notes from today and the deltas from before, during and after.

 

LVEA transitioned to LASER SAFE

The LVEA has transitioned to LASER SAFE.

Increased DB1 diode current

This morning the main laser screen reported an output power of ~152 W.  This is significantly down from yesterday's value of
~180 W.  Decided to increase the diode current of DB1 to the maximum.  The reported power jumped up by ~20 W.

    Other fine tuning might prolong the inevitable.

I adjusted the diode temperatures for DB1 a little.  The power indicated on the MEDM screen went from 135.3 W to 141.3 W.
The Beckhoff main screen indicates a power of ~184 W.

D1 is 27.0 degC, was 24.5 degC
D2 is 27.7 degC, was 24.5 degC
D3 is 22.5 degC, was 21.5 degC
D4 is 23.5 degC, was 23.5 degC
D5 is 22.5 degC, was 23.0 degC
D6 is 27.5 degC, was 24.5 degC
D7 is 24.5 degC, was 24.5 degC

    Altering the temperature of D3 does not do much.  D3 is pretty much dead in my opinion.

PRMI flashes

T Vo, Sheila

We aligned PRMI a little bit.  We started with PRX and PRY, and saw that our PRM alignment for PRX and PRY fringes has shifted by about -300 urad in pitch since Jan 17th.  We used picomotors to center the IMC WFS because we saw that there was a shift on IM4 trans QPD today around the time that Cheryl would have been on IOT2L.  Centering only moved IM4 trans a small amount back to where it was before Cheryl's work.  We aren't sure if this is the reason for the shift in alingment of the input beam. 

I was able to see PRMI flashes, not well alinged, by moving PRM, PR2 and BS, the overall impact was to move PRM back towards the Jan 17th alignment.  We now have flashes on POP 90 of around 10 counts, (there is a 10 count offset, so flashes go up to 20 counts) with 1.2 Watts into the interferometer.   We should be getting something like 100 count flashes, but it might just be that we aren't well aligned yet.  I haven't adjusted anything on the table or adjusted teh demod phase, although the demod phase seems OK. 

The attached screenshot shows the alingment for which we get small sideband flashes in POP90.

OM sliders offloaded, beam centered on OMC input QPDs.

[Keita, TVo, Jenne]

With the OMC free-swinging with no alignment slider offsets, we closed the OMC ASC loops with OM2 and OM3 as actuators.  OM1 is at 0 slider offset in pitch, and a small 450urad in yaw.  This told us how we needed to offload the OM2 and OM3 sliders such that we're near the center of their range.

Much of the offloading needed was in pitch.  For OM2, we removed the front earthquake stop holders, loosened the setscrew for the pitch adjustment (it was already loose enough that it fell out, but Keita caught it and re-installed it).  We noted the OSEM Wit value when the pitch offset slider was at its large value, set the slider to zero, then adjusted pitch to set the OSEM Wit value back to what it needed to be. Keita tightened the setscrew and replaced the earthquake stop holders.  OM2 was then rotated a small amount to offload the yaw slider, and we re dogged the cage to the table.  The procedure was largely repeated for OM3, although we did set some dog clamps as references, then moved the OM3 cage a little closer to the door so we had access to the pitch adjustment screw.  OM3 was replaced after pitch offloading, yaw was offloaded, and OM3 was re dog clamped down to the table.

We have beam on both OMC QPDs, so should have no problem reclosing the ASC loops and then locking the OMC if we so desire.

N.b., beam height incident on OM1 was 104 mm, beam height incident on OM2 was 98 mm, beam height after reflection from OM3 was 102 mm.  

To do:

• Fast shutter position set (for refl to hit beam dump)
• Fast shutter wire dressing
• OMC shroud replacement on side nearest HAM5
• AS_C path check
• AS WFS path check
• OMC Trans path check
• OMC refl path check
• Replace glass beam dump with new silicon carbide version

ETMY PenRe mechanical issues

So, after I rebuilt the ETMY PenRe mass assembly D060341 late last week, this morning Travis went to exercise it's central Pitch adjusting bar to check for it's ease of slide, needed for in-situ alignment.  He found that it was extremely difficult to move.  (I hadn't thought it was so bad last week, but I used isopropanol to insert it and was able to have it slide around - probably finding the lucky and illusive "sweet spot" with these.  Now, the isopropanol wasn't even helping.  Once mated to the monolithic ETMy optic set we will not be able to use isopropanol to get it to slide anyways fo fear of dripping onto optic/fibers.)  We've had troubles with this fit in the past and believe there is an issue with tolerances in the drawings which we never reworked, instead just "making due".  Tried as we might, when dry we could not "make due" today.  We even tried filing down any miniscule burrs and even swapping with the 1 remaining spare, which seemed just as bad of a fit.  So, we've lost a day to this now and will need to consider something more drastic in the morning such as opening up the center hole in the main mass D060342 and rebaking the part or find a suitable spare in 3IFO inventory (not trivial because it means painfully relocating an pre-assembled lower QUAD unit into a clean space, opening it, disassembling it's PenRe and hoping for a better fit with the borrowed parts).  TBC...

EY PCAL Periscope Vibration Absorbers Installed

Today, Jim and I installed the 4 vibration absorbers on the EY PCAL Periscope. Since we only had the one type of D1600401, we had to mount them on the 45deg spokes as shown in D1200174 on the last page. See attached pictures, though kind of hard to get good shots due to access.

One issue we ran into is that the vibration absorber assembly drawing (D1002424) says to use 1/2" long 1/4-20s with a washer to mount D100895 to D1600401. We found that the screw would still poke out the back even with a thicker washer. We had to double or triple washer stacks to keep them from protruding.

Preparing 10" gate valve at CP4 for equipment installation

Tightened the (as found closed) 10" gate valve at CP4 and then vented the non-CP4 side.  There may have been a slight improvement in CP4's pressure as the result of this exercise (see attached graph).  I was working alone and wasn't able to observe the peak pressure on the connected pump cart when the unpumped "dead volume" of the gate valve was valved-in to the pump cart but I could tell that the gas load was enough to slow the pump cart's turbo.  

Tomorrow I will remove the 10" gate valve's zero-length reducer and install the turbo, gauge, valves and RGA components needed for the decommissioning of CP4 later in February.  

Testing EX HEPI pump control running on Beckhoff

Filiberto, Hugh, Patrick, Richard

This morning Hugh and I took the end X ISI guardian to ISI_DAMPED_HEPI_OFFLINE. Hugh and Filiberto then went to end X and Filiberto moved the wiring from the existing HEPI pump controller box over to the Beckhoff box. We found some minor issues with the Beckhoff PLC code that I corrected. Restarting the PLC code tripped off the power to the HEPI pump motor and I went to end X to reset it. We have since tuned the Beckhoff PID (actually just PI) and will leave it running overnight.

Filiberto, Richard, Patrick

Today we took it off of PID control and ramped down the VFD. Filiberto then went to end X and connected the VFD readback signals to the Beckhoff terminal. We then turned the PID back on. It is currently keeping the differential pressure at 70 psi.

Prepped IP4 for installation

Finished venting IP4 with bottled UHP N2 (started Friday afternoon then halted).  Also vented (with bottled UHP N2) non-VE side of closed 12.8" gate valve (new VAT valve) mounted on OMC tube and having 16.5"-2.75" CFF zero-length reducer flange with 1 1/2" pump port valve.  New valve doesn't leak!  

Chandra will be in early tomorrow to remove connected equipment and supervise installation of IP4 onto the OMC.  

Shift Summary - Day

TITLE: 01/29 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC

STATE of H1: Planned Engineering

INCOMING OPERATOR: None

SHIFT SUMMARY:

LOG:

16:00 (8:00) Start of shift

16:15 (8:15) Hugh to End-Y -- HEPI filter change

16:22 (8:22) Ken to End-X -- Piping work

16:48 (8:48) Hugh out of End-Y

17:47 (9:47) Bartlett to termination slabs -- ITM camera work

17:57 (9:57) Phil to End-X -- Looking at cabling for HEPI

18:36 (10:36) Cheryl to IOT2L -- Align cameras

18:45 (10:45) Ed to HAM6 -- Inspect wire

18:58 (10:58) Jenne, Keita and TVo to HAM6

18:59 (10:59) Phil out of End-X

19:00 (11:00) TJ and Jim to End-Y -- PCal baffle work

19:03 (11:03) Hugh to LVEA -- Retrieve hardware

19:12 (11:12) Phil to End-X

19:15 (11:15) Hugh out of LVEA

19:45 (11:45) Cheryl out from IOT2L

20:01 (12:01) Bartlett out for lunch

20:08 (12:08) TJ and Jim out of End-Y

20:10 (12:10) Phil and Hugh out of End-X

20:20 (12:20) Jenne, TVo, Keita out of LVEA

20:59 (12:59) Bartlett to termination slabs -- ITM camera work

21:05 (13:05) TJ and Jim to End-Y -- PCal baffle work

21:10 (13:11) Kyle to HAM4 -- climb up OMC tube

21:13 (13:13) Travis and Betsy to End-Y -- Putting ETMY back together

21:29 (13:29) Ed to CER -- Terminate cables

21:35 (13:35) Kyle out from HAM4

21:53 (13:53) Peter and Gerardo to Optics Lab

22:06 (14:06) Bubba and Mark to LVEA -- Work on snorkel lift

22:27 (14:27) Elizabeth to HAM6 -- Scan components

22:36 (14:36) Patrick to End-X -- Reset power to HEPI pump control

22:40 (14:40) Nutsinee to ISC Rack

22:40 (14:40) Bubba and Mark out of LVEA

22:50 (14:50) Nutsinee out from ISC Rack

22:53 (14:53) Patrick out of End-X

23:13 (15:13) Bartlett out from termination slabs

23:26 (15:26) Jenne, Keita, and TVo to HAM6

23:30 (15:30) Peter and Gerardo out of Optics Lab

23:47 (15:47) Elizabeth out from HAM6

23:49 (15:49) Terry to SQZ bay

23:54 (15:54) Ed out of CER

0:00 (16:00) End of shift

EX ALS fiber path might need realignment

We need to restore ALSX for peeking down the X arm.

We have OK fiber power (though RefCav trans is smaller than it used to in O2), and polarization at EX is not bad either, but there's no beat note.

Left: O2, Right: Now.

Could be that the frequency is too far off or the alignment is somehow bad.

aligned REFL path on IOT2L

The beam on top periscope mirror is roughly centered (this is a change from a few weeks ago), so the beam coming off of the bottom periscope mirror was too high. Adjustments made to clear iris/HWP/CW and beam dumps, and REFL, WFS1, WFS2, and camera recentered.

State of the CDS computing system

I'm emerging from sick leave, so this would be a good time to give a CDS computing summary:

Timing is in error. At around 3am PST Thursday 25th the MCA atomic clock time distribution system went into alarm. Trends suggest its time was varying for about an hour, and then settled to a static large offset. All three comparators in CS, EX and EY see bad times and are reporting the error.

h1oaf model is now consistently running long and reporting timing errors. This started Tue 16th Jan, presumably due to filter changes. I am investigating.

New filters need to be loaded for h1sqz, h1ascimc. If we don't get to this today, we'll cover it tomorrow during maintenance.

Vent Meeting Minutes

Commissioning:

• HAM6 OM alignment next two days
• Make sure ALS is working
• ISCT1 alignment
• IR-only glasses no longer okay
• PSL deferred
• Flange needs final torquing at HAM6
• HAM6 South door off as prep for VOPO
• During X-arm Feb 6th comm work-No entry to HAM6, no VP work
• ZM1 install on hold
• ITM camera install, images on both, need to lock them down
• Tuesday Feb 30th-Laser Safe 7-10AM

CDS:

• ITM work
• Take CS Beckhoff down, scan for hardware

End-Y:

• PCal install vibration absorber
• Later this week NGG pump commissioning
• HEPI end station filter change ongoing

Mid-Y:

• Expect alarms for vacuum work

End-X:

• Conduit work
• Take ion pump off