Exhaust flow through piping is sustaining a mechanical vibratory resonance -> Increased flow by adjusting regulator 1 turn CCW -> this increase flow stopped the vibrations but will result in a lower dewar vapor pressure which will cause the nominal %open of the LLCV to increase -> trial and error should produce a happy medium -> if not, then piping will have to be clamped differently 

Randy, Mick, Mark, Chris & Zack
Pretty Straight forward here.  Flew Support Table Over Chamber, lowered into cleanroom.  Hovered over the Support Tubes, bolted up, dropped load, torqued bolts.  Jacked Support Tubes up into V-Blocks and clamped tubes to blocks.  Removed Support Table.  Apollo crew will conclude the job this afternoon with a bit of hardware removal.
Nice work guys--H

Couple photos, Zack & Mick.

Jim, Hugo,

HAM3-ISI was re-balanced for testing to start over today. It is now locked for IO work.

We will unlock after lunch. Measurements will be launched at the end of the afternoon.

Note: IO still needs to add a beam dump next week. Balancing will be re-adjusted then.

Mark B.

As mentioned in comment 4804 below, I'm going to do a set of DTT TFs for ITMy M0 and R0, starting now.

- Chris, Giacomo, Rodica, Cheryl

IO:
Input beam to MC was aligned to the irises in front of MC1 and MC2.  MC1/3 were aligned to get the MC flashing.  Remaining two HAM Aux's had FC pulled and surface issues handled (left over FC and possibly others that Rodica can comment on).  The two HAM Aux'es that were moved for MC alignment were reinstalled using their alignment templates.

I put in an alog earlier today that lists the 2" optics that are installed in HAM2 in the IO periscope and steering mirrors AROM RH1 and ROM RH1.

HAM2:
The day began with Chris putting in most of the effort to vacuum and wipe  surfaces in HAM2.  Betsy and I found particulate on MC1's cage and throughout the chamber yesterday, and Rodica saw that the HAM Aux optics were populated with particulate pretty much as soon as FC was pulled.  I vacuumed MC3 and found particulate everywhere, both black and white flecks, and shinny (clearly metallic) flecks.  

We have two silicon wafers on the HAM2 table to monitor particulate.  It's not clear to me now, that particulate that lands on these is necessarily particulate added to the chamber, because it seems possible that it could be particulate that's already there and just being moved around.

Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot from approximately 6 PM Nov. 28 to 6 PM Nov. 29. Also attached are plots of the modes to show when they were running/acquiring data.

List of 2"optics in HAM2 in the IO periscope and the steering mirrors to MC1:

M-38-UNP, SN-01, upper periscope mirror
- no defects on front face

M-38-UNP, SN-22, bottom periscope mirror
- no defects on front face

M-38-UNP, SN-65,
- looks good, effects on the back, but not the front
- installed as AROM RH1

M-38-UNP, SN-12
- defect 4mm from center
- installed as ROM RH1

CP6 overfilled following today's LN2 delivery -> This is uncharacteristic for this system (CP6) -> Investigation shows everything is nominal except that the dewar 25 psi < vapor pressure < 30 psi which is ~10 psi greater than normal for this system -> I observed that the manual blow down circuit was frosted which indicates that it was used to vent the displaced vapor during the fill (as expected).  It may be that the fill rate is too high resulting in the larger than normal head pressure increase for a fill(?) -> PID response too slow for rapid change(?) -> I decreased the time between PID samples from 50 sec to 20 sec -> Today's driver is associated with past irregularities -> I'll investigate if this driver is doing something different from the other drivers

During the quiet lunch hour Mark ran 3 of the 6 DOF TFs on the ITMy main chain.  The TFs indicated the ITMy looked healthy with resonance peaks in appropriate places.  At 4pm, Vincent reported that he could not run ISI measurements because he ITMy watchdog was tripped.  A quick investigation by Mark, Vicent, Hugh and I on DV indicates that indeed the ITMy seems rung up in Transverse (a motion only driven by the single side BOSEM).  As well, while we can enable the damping loops and watchdaogs such that signals wiggle out the far right of the ITMy MEDM, we aren't convinced damping is actually happening on the ITMy as seen by BOSEM channels on DV, and a quick noisy TF of longitudinal motion.  No mechanical work was undertaken on the ITMy today.  Possible culprits:

SEI work up top in the morning and afternoon could have jarred the ITMy into an EQ stop - will check in the morning, but doubtful as the BOSEM (sensors) postions look unchanged from the morning.

IOP work to remove BS which was hindering measurements, including frontend and model reboots/restarts to everything related to the IOP - Maybe we need a fresh reboot/restart? Will press on with troubleshooting tomorrow.

WP#3582: The h1susb123 IOP model (h1iopsusb123) was modified to disconnect the Beam Splitter Suspension from the trip circuit. Now only ITMY can trigger the DACKILL on this front end. 

BS tripping the DACKILL was severely disrupting the ITMY commissioning, it was accidentally left in my model when I first built it last week, sorry.

While working on floating BSC1, I noticed that the St1V1 actuator looked misaligned. I used some shims to measure, and while the gaps between the magnets on each side of the coil were different (.130 on one side, .060 on the other, the spec is .090 +/- .015), the parallelism wasn't too bad. The alignment of the actuators is checked out as part of the early testing, so the misalignment was likely not due to improper assembly. It's possible this actuator was whacked at some point, but it seems improbable that would result in a purely horizontal move (the coil is only supported at one end and would probably rotate instead of translate, and not be parallel anymore). I checked all the other actuators on St1 and St2, and they all pass, so I'm kind of at a loss. Pictures forthcoming.

Forgot to add: the alignment of this actuator has been fixed.

Large swings in CP8 control following yesterdays changes -> Looks like I had mistakenly restored 0.10 as the PID integral parameter last night instead of the nominal 0.01 -> re-entered 0.01 this morning

The AC units and HEPAs in the laser room have been turned off, and the make up air reduced to 25% to maintain an overpressure in that room. The anteroom HEPAs were turned to Standby, which is 55%, also done to maintain an overpressure. The lights in both rooms have been turned off, but the monitors and computers are left on, since I couldn't get those from outside. I'll set the fans back to their original values at the end of the day and post the results. This is to see how the temperature of the room stabilizes in "science mode" conditions.

Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot from approximately 6 PM Nov. 27 to 6 PM Nov. 28. Also attached are plots of the modes to show when they were running/acquiring data.

As found clearance between stop screw and stroke-factor lever was about the thickness of a sheet of paper, i.e. not in contact for 0% open PID output -> Confirmed that needle closed for 0% open PID output after change -> effect of adjustment on stroke (range) ignored for now

At the request of Dave and Besty, I've used Joe and Adam's Instructions to building SUS infrastructure from scratch (supplemented by more stuff by me) to fill in everything* needed for H1 SUS ITMY, including all filters and EPICs values, using H1 SUS ETMY as my starter QUAD. Note that I've changed EPICs values that are not common to each QUAD, namely:
- Zeroed out alignment offsets
- Installed correct ISI<->SUS projection matrices for H1 SUS ITMY
- Zeroed out non-diagonal DRIVEALIGN matrix elements.
After which I've saved a safe.snap, which lives here:
/opt/rtcds/userapps/release/sus/h1/burtfiles/itmy/h1susitmy_safe.snap

Attached is a detailed log of my actions, such that they might be turned into a script one day, if not at least used to fill out the wiki instructions...

* "Everything" excludes correct optical lever calibration gains, and OSEMINF open light offsets and gains, which need to be measured and installed when possible.