Expect to start pump down of Y-end today after Dr. appt. 

I aligned the IMC to a marginal state but good enough to see centering behind MC3, and through the FI, and to get a REFL beam to HAM1.  The alignment is bad enough that the 0-0 mode is scarce so power is low most of the time.

I spent a great deal of time on soft covers, both when they were all closed, and then again when I needed to have one open.  When I had one soft cover open, it was necessary to redo all the doors and have all 4 doors on HAM2/3 open, to ensure that the fabric wasn't rubbing the ISI (which was floating).  

This situation came about because Hugo thought I was worried about the ISI locked vs unlocked position, which I'm not.  I am worried about there ISI locked after the vent, then payload change on the tables vs refloated and rebalanced position.  Somehow Hugo thought I was saying I needed to work on the tables while they are floating, and I thought he said he couldn't lock them for my work because he would have to redo all of his transfer functions.  We have got to get this kind of thing straight so here is my part, in bold letters:

*** ISI in HAM2/3 - LOCKED (no payload changes) VS UNLOCKED (no payload changes) CHANGES THE POSITION OF THE TABLES VERY LITTLE ***

Given the troubles I had with the IMC alignment tonight
*** ISI LOCKED, THEN PAYLOAD CHANGE VS REFLOATED AND REBALLANCED, AFTER A PAYLOAD CHANGE, SEEMS TO BE A PROBLEM ***

From my observations in chamber, clearly something happened somewhere in HAM2 or HAM3, or both.  PSL pointing seems OK in HAM2, but beam is low at MC2, so that's a possible issue too.  PRM needed max. drive in pitch to get REFL through the baffle just before beam goes to HAM1, which could indicate a problem with PRM, or that the PRM is just responding to a change in the HAM2 ISI.

Status:
- beam on PSL wall seems OK - evaluating the picture will give me more info 
- MC2 changed in pitch by 500 urad in pitch to get IMC to flash, though IMC clearly needs more alignment
- PRM is maxed out in pitch to get REFL through the baffle to HAM1
- beam is low at MC2
- beam height at MC3 EQ stop baffle is good when driving MC2 with the 500 urad pitch bias
- beam is going through FI chain to PRM and back to REFL

I read an alog from a few days ago, which suggests the HAM2 ISI rotated and shifted and tilted from it's locked position.  I think the numbers in the alog are in counts.  I'll look into it tomorrow (later today).

HAM3 may have also seen some big change when floated and rebalanced.

PSL beam on the PSL wall was roughly in the same position - I have a picture, and will compare more closely tomorrow. 

Beam at MC2 is low by about 4mm, which means an angle change of 250 urad coming from HAM2, which could be a change in the input beam or tilt of HAM2.

After the IMC was flashing, although still not well aligned, the beam was going through the FI and REFL was returning from PRM and making it into HAM1.  Sheila and I did see that PRM did not return to a consistent position when driving it around it's max. pitch, which means it's hitting an EQ stop.  This needs to be looked at after I understand what happened to HAM2 and HAM3.

Conclusion:
I was hoping to sign off on the IMC and HAM2 alignment, but there are multiple issues with the current state of the IMC/PRM/REFL beam.  Some sort of beam does make it through the IMC and FI and back to HAM1, even if it's ugly and clipped (Keita's alog), so we could just close up and deal with the alignment issues under vacuum.  I find it easier to diagnose these issues at air, and would suggest we might want to have the ISIs in HAM2 and HAM3 locked and flash the IMC again, after I've had some time to look at trends.

Keita, Sheila, Kiwamu

 We installed a high power beam dump in HAM1 this afternoon.
Then we attempted to align the interferometer REFL beam path in HAM1 to let it go through a viewport, but we gave up doing it this time.
We will try to align the REFL beam next time in near future when the IMC flashes.


Installation of high power beam dump:
 Since Cheryl recovered the alignment of the IMC this afternoon and made it flashing, we were able to see the interferometer REFL beam which is downstream of the IMC. The first thing we did was re-positioning of the first steering mirror such that the REFL beam lands on the center of the mirror. The second thing was the installation of the high power beam dump in the REFL path. By design most of the REFL beam is supposed to be dumped at this high power beam dump using a high-reflective BS. After the dump was placed and dog-clamped the beam splitter was aligned such that the reflected beam hits the center of the beam dump.

Alignment of the REFL path to viewport:
 We attempted to align the REFL path. The beam after the high-reflective BS is the one which is supposed to get out of HAM1 through a viewport to ISCT1. As the beam goes through the high-reflective BS the beam became weak and basically the beam power was too low to work with. First of all the sensor card wasn't useful any more due to the too low power. Alternatively we tried to see the beam from the outside using an IR viewer but it was quite hard to tell if we were really seeing the beam because the beam spot was a bit too far away (~ 2 m) to look from the outside and also simply too weak. So we gave up this time. If we can bring an IR viewer in the chamber, this might help us to see the spot. In any case we will come up with some alternative strategies for this issue. Another thing which prevented us from a smooth work was the PRM watchdog as described below.

PRM watchdog kept tripping :
 PRM wasn't in a great condition in the sense that it kept tripping every 2 minutes or so. Because the interferometer REFL beam relies on the alignment of PRM, we had to stop working and wait for it many times. After we carefully kept watching the MEDM screens, eventually we got a hypothesis --- due to a big bias applied on the top mass in pitch, enabling the control slowly brings the PRM alignment to a point where the OSEM readout hits the ADC watchdog threshold of 10,000 counts. Actually the pitch bias had been increased this evening by Cheryl and Sheila to get the beam retro-reflected and it is at the edge of the MEDM slider range.
 Another thing I would have to mention here is that I accidentally leaned on the HAM2 ISI when I was checking the beam around. This tripped the watchdogs of all the suspended optics on the HAM1 table at once. After we recovered all of them we found PRM behaving in that way.

RFEL beam seems clipped :
 Keita claimed that the beam looked clipped at its bottom and slightly its side. This was found after the PRM watchdog mambo jumbo. It is unclear what happened.
 

Went in to BSC6 while Apollo crews are hanging the door.

There were following things left in the chamber, and all of them were removed:

• In-chamber boots.
• A sock for SUS.
• TM protection plate for SUS cage (packed and bagged by Apollo).
• Metal step for in-chamber work.

I didn't see 1" witness mirror on the floor but I don't know if it's supposed to be there (it was not on Jody's check list either). Witness plates were there and of course they were left in.

One thing to note: Things are dirty. I was able to see lots of dust particulates on the witness plates on the floor as well as TMS mirrors (see pictures). ETM was better, but I was able to see some glints when I used a flash light.

I wiped the floor, about 1sqft in front of ETMY and maybe 2sqft right under TMS using Vectra wipes with alcohol, but it was not clear if I was removing dust so I stopped and told Apollo people to close the door. The wipes I used to wipe the floor was saved but I don't intend to do anything with it.

Anyway, as far as I'm concerned, BSC6 is ready to be pumped down.

Full pictures are available at resourcespace:

https://ligoimages.mit.edu/index.php?url=https%3A//ligoimages.mit.edu/pages/search.php%3Fsearch%3D%2521collection1307

Attached are plots of dust counts > .3 microns and > .5 microns in particles per cubic foot requested from 5 PM Apil 17 to 5 PM April 18. Also attached are plots of the modes to show when they were running/acquiring data.

Data was taken from h1nds1.
T0=13-04-18-00-00-00; Length=86400 (s)
1260 seconds worth of data was unavailable on this server
1440.0 minutes of trend displayed

I closed it -> How long had this been open?

Discussions regarding the preparedness of Y-end for pump-down revealed an uncertainty as to whether all of the non-Class A items had been removed from BSC6.  BSC6's North door had been "hung" with (4) bolts several days ago, as is typical during long periods of in-chamber non-activity, with the understanding that re-entry into BSC6 would occur.  Re-entry was not needed and, days later, Apollo was instructed to install the remaining door bolts to allow us to pump-down the Y-end station.  In order to be certain, BSC6's north door was removed today and, indeed, several non-Class A items were discovered inside.  These were removed.  The door was re-installed after a signed Chamber Exit Checklist was presented to Apollo.  

Apollo disassembling the clean room over BSC6, recurrent ADC overflows on H1IOPSEIB6, large motion on suspensions
Sheila transitioned the LVEA to laser safe
Filiberto pulling cables to HAM5
Jodi, Mitchel, moving soft covers on the doors of HAM2 to prevent interference with ISI
9:39 Dave restarted the DAQ to remove h1ecatc1 channels from the EDCU
2 take cover drill phone messages from Hanford
Dave working on alarm settings
Sheila transitioned the LVEA to laser hazard
12:45 Cheryl starting work in HAM2,3, flashing MC, checking beam paths. Soft covers eventually removed from both HAM2 and HAM3 due to interference with ISI
Washington Crane onsite for crane inspection
2:28 Vacuuming at end X begins sets off dust counter
3:27 Michael R., Pablo going into H2 PSL enclosure to work on PCAL
Door removed from BSC6 to remove items in preparation for vacuum pumpdown. Kyle to start pump, but not attach it to the chamber yet.

I have reconfigured the cds alarm handler to raise alarms on the IOP STATE_WORD (that which is shown on the new CDS OVERVIEW medm screen). The state word goes into red major alarms except if the OVERFLOW condition is set in which case it is a minor yellow alarm. I took the opportunity to bring all the safe.snap burt restore files for the IOP models up to date.

The ALS SHG is now producing 0.57 mW of 532 light. One thing that I noticed while optimizing things is that the performance of the dichroics depends quite a bit on the polarization of the IR beam, so I had to add a second dichroic so that I could optimize the polarization.  I also moved the DC PD into the main green path to have a better monitor of the green power than the pick off beam.  

Some power measurements in the doubling path:
Infared powers:  240mW coming onto table
Pick off for IR DC PD: 9.85mW
remeasured main beam after pick off: 247mW (measured at waist)
The first dichroic rejects 239mW of IR
IR through first dichroic varies with polarization from 200uW to 66uW, I need to remeasure the value now that I optimized the polarization
After the second dichroic I don't see any light when the SHG temp is far from phase matching (not more than 2uW), which is independent of polarization.  

A partial phase matching curve is attached.  The thermistor calibration is only rough, so the temperature read out is not really linear with the actually temperature over 10s of derees C, so the measured curve is not exactly a sinc function.  

Last night I left the SHG running overnight, the second plot attached is the effective nonlinearity (green over IR^2), conversion efficiency (green/IR), green power and IR power each normalized to their means.  You can see that over 15 hours, the power from the PSL slowly drifted up, which the green power also did.  All the fluctuations except for one glitch at 13.5 hours are well within the 5% requirement from T1300174.  

The last plot is a histogram of these normalized values, the standard deviation of the green power is 0.67%.  

The data and m file are also attached.  

• Longitudinal: -0.4 mm (South, -X)
  • Tolerance: ±3 mm
• Lateral: +0.1 mm (West, +Y)
  • Tolerance: ±1 mm
• Vertical: +0.4 mm (high, +Z)
  • Tolerance: ±1 mm
• Pitch: 7 µrad down
  • Tolerance: ±55 µrad
• Yaw: 52 µrad CCW
  • Tolerance: ±190 µrad

The ITMy elliptical baffle was also aligned in lateral and vertical position.  Its final aligment errors are:

• Lateral: +2.2 mm (North, +X)
  • Tolerance: ±7 mm
• Vertical: -2.4 mm (low, -Z)
  • Tolerance: ±7 mm

The ITMx elliptical baffle was not aligned due to a mounting issue described in aLOG 6104 and its comments.  This baffle was left in the chamber so as not to hold up progress on chamber close out for the HIFO-y test.

  Andres R. & Jeff B.  

   We completed taking the Transfer Functions and Power Spectra data for I1-PRM. The data files are attached below. There is a small peek at 0.85Hz, which is suppressed under damping. All scripts and data files have been committed to the SVN repository. We will wait for the testing group to review the results data before taking additional action on I1-PRM.     

The EDCU had problems with the ECATC1 ini file giving false connection status numbers. I removed this ini file from the DAQ and restarted at 09:39

Attached are plots of dust counts requested from 5 PM April 15 to 5 PM April 16.

I have not included plots of the counts in the optics labs, because of the 'nan' in the data when I rebooted the IOC to test a new version of the code. I did this starting at 3:06 PM April 16. The modified code should fix this bug and is scheduled to be installed next Tuesday.

Door covers are so tight the touch the ISI on both sides of HAM2.

IO closeout still to do::
- check beam on psl wall 
- flash IMC
- align REFL to HAM1 - needs coordination with ISC crew
- align HAM2 QPD
- check all baffles
- check POP/ALS path in HAM3
- align West side of HAM2 beams with viewport simulator.

Viewport simulater was crammed in the HAM2 clean room across the steps, so had to be moved, and will need to be wiped again before hanging on an open HAM2 door.

Gerardo finished up the optical lever periscope for the BS.
The  Y-arm baffle is aligned. 
The  Y-arm baffle needs to have the brackets removed to fully suspend it...do not forget this
The  X-arm is not aligned due to the mounting bolt pattern issue he encountered
The platform remains inside under the X baffle
IAS needs to finish breaking down our equipment and stowing it

Mitch, Jim, Hugo,

HAM2-ISI was repayloaded, rebalanced, and its lockers (all) were adjusted. We gave HAM2 back to SUS so they can proceed with testing.

 CPS readouts (counts) with the ISI locked, and unlocked, are displayed below.

Even though they are a bit mis-centered (away from 0cts), CPS Targets are far from contacting the sensor. We will leave the CPSs un-zeroed and use a bias in the control loop, as we have done so far.   

Cables rubbing against the chamber/support tubes could be an issue for HEPI commissioning. We took care of dressing the cables away from the chamber and the support tubes, as we could without unplugging anyone (See attached Pictures). It is good practice to always adjust installed cables so they are cleanly dressed, away from the chamber and the support tubes, before connecting them to a feedthrough.

Looking at PR2 transfer functions ran yesterday night, an extra resonnance appears at 2.8 Hz for M1 pitch to pitch transfer function when comparing it to the model and phase 3a testing transfer functions ran on december 2012.

Betsy and Travis are investigating to find its source.