I put together this  T1400371 procedure for aligning the 90/10 BS in HAM3. It describes the way they did the alignment at Livingston (Option 1, green beam from HAM1, IOTR table would need to move) and the way that Keita would like to do it here (IR beam from HAM3, no need to move IOTR).


All the parts needed are "mostly" ready. Here is a summary:

- BS 90/10, post, clamp (mirror is cleaned and installed in mirror mount)
- V-shaped dump, post, clamp (ready)
- IR laser diode source (in optics lab)
- spare clean sled (in optics lab, can be used to mount the laser source and collimator in HAM3, if needed)
- 2 spare 2" HR 1064 clean optics (on optics table in OSB optics lab - I left there also a clean 2" HR 532)
- Missing: IO style posts for mounting the steering optics (Corey and Cheryl working on it)

Operators Log 05/30/2014
Day Shift Summary
LVEA Laser Hazard 

08:49 Filiberto – To End-Y working on cable repairs
09:00 Kyle - Moving RGA cart to BSC7 area
09:00 Hugh – Working on external cabling at HMA5/6
09:35 Dave & Thomas – Working on TSC-X and Hartman tables
09:45 Rite Choice on site to pick up pallets and scrap wood 
10:04 Keita & Sheila – Going to End-X
10:06 Kyle – Going to End-Y to recover test equipment
10:45 Betsy & Travis – Working in the West Bay cleanroom
12:49 Karen – Going to End-Y
13:08 Betsy & Travis – Working in the West Bay cleanroom
13:17 Dave – Working on TCS-X and Hartman tables
14:18 Karen – Back from End-Y
15:22 Betsy & Travis – Out of the LVEA

Arnaud may run some measurements on the SUS in HAM5 so I delayed these to start later today.  Running on OPSWS8

When the septum was removed, the cabling between HAMs 5 & 6 were disconnected so the crew could deal with all the bolts.  I asked FClara to reconnect the cables to the WHAM6 NW feedthru, SUS & ISC I think.  I'm not familiar enough to distinguish these so I left those to him.  When they are sorted out I will complete the cable/feedthru protecting.
Meanwhile, HAM5 ISI sensors are live, don't disconnect any cabling, you'll have to cut zip ties to do so.

In preparation for the vent, I centered POP QPDs so that we can use it as an alignment reference when we will install HAM3 beam splitter.

Right now both POPA and POPB PIT and YAW are all within +-0.015.

QPDA sum is 56.3, QPDB 51.7 using straight shot.

POPA picomotor counts are: X -331, Y -28257.

POPB picomotor counts are: X 4151, Y 20661.

Not unlike TMS picomotors, these are sort of degenerate. You can use pico B to center QPDA, then pico A to center QPDB, and repeat thousands of times to eventually have a good centering. You can also overshoot repeatedly to make it quicker. For example, when QPDB is too low while QPDA is centered, you use pico A to bring QPDB up, then pico B to bring QPDA down, and repeat.

The sled is sensitive to even 1 step of the picos. Medium step (100 steps) is safe to use without worrying too much about losing the beam, but if you want to use Large (1000 steps), be prepared to lose the beam on both of the QPDs.

Travis, Betsy

Over the last few days, we assembled an upper structure which will eventually attach to one of the ITM lower structure that is currently trapped in chamber.  We finished assembling the 4 top stage blade cartridges and 2 top masses for this unit.  We then mounted all of them plus top wire segments and parts of the table cloth to the upper structure.  We will mount the whole cube to the test stand on Monday and then it will wait for it's other 2/3.

Thomas, Jim, David and Dave

We were able to establish serial communications between the h1hwsmsr computer in the MSR with the HWS  Teledyne Dalsa Pantera 1M60 camera on the X-arm TCS table in the LVEA. We suspect communications were not working earlier due to serial synchronization problems, which were cleared when the remote transceiver (RCX CLink) and camera were power cycled. We discovered several MEDM/Beckhoff/Wiring issues with the power control of these devices which Thomas is going to resolve over the next few days.

Hugh - Working on external cabling at HAM5 and possibly HAM6
Dave - Working on the TCSX table and prepping for ring heater test
Richard - Working on end stations ESD
Kyle - Moving RGA cart to BSC7 area
Lisa & Sheila - Setting fiducials at HAM2  

no restarts reported.

David / Greg / Thomas

TCSX:
- QPDs tested and appear to be working correctly. Need to locate different translation stage to calibrate.
- laser will be running overnight. (TCSY laser, power supplies and chiller are all OFF).
- FLIR camera mount drawing added to DCC ( https://dcc.ligo.org/LIGO-D1400168 )

HWS End-X:
- mounts and optics have been staged

Corner HWS clamping plate: modifications to be made by Apollo

Polarisers:
- guys at Caltech looking at a way to bond these so that nylon screw not required to secure to the mount.

The idea is to wrap up commissioning by Saturday night. The ring heater stress test can proceed on Sunday. The vent can start Monday.

• IMC/PRCL adjustment: Prepare to move MC2: 1.95 mm towards HAM1 (IMC needs to get shorter).
• EY ESD fix: No in-vacuum work planned. Do we need to discharge?
• Conflat for mirror discharging: Need to refit in EX.
• Camera ports: Put new viewports in (need ECR, Corey).
• EY QPD centering: nothing to do.
• EX QPD centering: Friday morning (Keita, Daniel)
• POP beam path beamsplitter: procedure by Lisa (Thursday)
  POP QPD sled was centered in the past (Keita lead)
• Change mode of ALS/POP periscope in HAM1: Tighten screws (next HAM1 vent)
• Are all in-vacuum picos working? yes.
• Test photodetector pods for leaking? No.
• Alignment fiducials:
  Mark IMC REFL on the wall, on ISCT (Sheila, Friday)
  REFL beam on WFS (write down TT bias)
  REFL beam parking position(?)
  Oplev readbacks
• AS port alignment: still need procedure (Lisa)
• TCS ring heater test: Sunday
• EY ALS WFS: Saturday
• Interferometer REFL beam dump?
• IMC trans beam clipping? no

I asked EE to make/fix the whitening cables and/or install temporary new cables that are shorter than nominal, whichever is quicker. The shorter ones are to be replaced in the future.

Two cables were fixed, and the two new short ones were put in place. After this, I still saw that one of the two fixed cables (H1:ISC-Y-65, this is the first cable for WFSB) still had a short circuit for one pin. Since they didn't have enough short new ones, and since the broken bit was only for one of the whitening stages which I can leave off, I decided to keep the defective cable for now and live with it.

I also asked them to swap both of the whitening chassis, as the whitening gain was all over the place even though the BIO readback looked good, which didn't make sense, and we were getting suspicious about the whitening. The new ones were put in place.

I measured the dark noise, and both of WFSs had some problem.

For WFSA, one of the 8 channels (WFSA-Q4) would suddenly rail when the whitening gain is 24dB or larger. Up to 21dB it looks completely normal, DC output increases as I increase the gain, but when the gain reaches 24dB it suddenly jumps from a few hundred counts to 32k. Disconnected the analog, repeated it, the same result. Swapped the BIO cable, the same result. Since this seemed like a problem of the whitening chassis itself, I put one of the old whitening chassis (S1101600, which is one of the two units pulled out this morning) back and it behaved good. The problematic one is S1101636.

For WFSB, one of the channels (WFSB-I2) had much larger low frequency noise (f<1Hz) than everything else. You can kind of see that in the plot I posted yesterday, but today the noise looked larger. Disconnecting the demod didn't do anything as far as the low frequency noise is concerned, disconnecting the analog out DB9 on the whitening chassis didn't do anything, but when I went to the remote rack I immediately noiticed that the DB9 cable connector on the AA chassis was loose. I disconnected it and the noise was gone. I reseated everything, and things look good.

To summarize,

1. Whitening chain is in a workable state after fixing some nonsense problems.
2. Two short cables should be replaced, one bad cable (H1:LSC-Y-65) should be fixed/replaced, after this commissioning window.
3. Whitening chassis S1101636 seems to have a problem for Q4 channel (that's the last channel of 8-ch chassis).
4. It's not clear if S1101601 (which was pulled out this morning) has a problem or not, but we have some suspicion.
5. S1101600 for WFSA and S1101602 for WFSB are in use now.

doors being craned for HAM5 and rigged such that closing the gate valve is not required

08:40 Kyle to start pump for RGA on BSC8 (WP 4647)
08:46 Aaron and Filiberto to end Y to fix short in WFS cables
08:47 Jeff B. to HAM5 to take PET swipe
09:07 Hugh to HAM5 to move equipment out of the way for door installation
09:08 Arnaud to HAM5 to take hammer measurements
09:22 Richard to end Y to drop components off for Aaron and Filiberto
09:30 Travis to LVEA test stand area to retrieve documents
10:05 Praxair driver approximately 15 minutes away
10:31 Luis Z. to end Y to install grounding wrist strap connectors on the electronics racks
10:50 Jeff B. and Andres done at HAM5
11:27 Corey to LVEA to put away equipment
12:13 Praxair truck leaving
13:11 Jodi, Travis and Betsy to the LVEA west bay
13:22 Kingsoft water to take water samples
13:27 Hugh to LVEA test stand to work on sub-assemblies for 3rd IFO ISIs
15:21 Keita to end Y to work on WFS
15:48 The septum has been installed between HAM5 and HAM6. The doors are tacked on HAM5. Sheila is transitioning the LVEA to laser hazard.

The doors are tacked on (4 bolts ea.) at ham 5. The septum is installed between ham 5 & 6 and bolts torqued.

Dan H. completed setting up of the HAM6 QPD sled yesterday.  With he & Keita both happy with the Dan's mode matching measurements, the Sled wrapped up and bagged.  Before doing this, positions of optics were measured (with a ruler +/- 1mm).  Here are distances measured:

• 133mm:  Edge of Sled -> L201 (center of lens mount)
• 223mm:  L201 -> L202
• 41mm:  L202 -> M203 (front surface)
• 88mm:  M203 -> QPD1
• 111mm:  M203 -> M202
• 63mm:  M202 -> M201
• 282mm:  M201 -> QPD2

Photos of the HAM6 QPD Sled are located here.

The WFS Sled, QPD Sled, Fast Shutter Beam Dump, and a bag of hardware/dog clamps are all in totes in the Optics Lab and ready to be payloaded on HAM6 (most likely early next week?). 

NOTE:  Still missing the Fast Shutter!  Still being designed/manufactured??

From a trend of the wind speed it appears to have gone invalid around 4:45 PM yesterday. A log of the error messages on the IOC is attached.
I restarted the IOC and set the alarm limits on the wind speed.

SLED work held off
doors to be installed on HAM5 after confirmation from SEI
septum to be installed between HAM5 and HAM6
HEPI is locked

Thomas V. installing software for HWS camera

Richard fixing cables for WFS at end Y

Peter NOT working in H2 PSL enclosure, waiting on missing screws

Field trip expected in control room around 11:00

model restarts logged for Wed 28/May/2014
2014_05_28 08:19 h1pemmx
2014_05_28 23:53 h1nds1

pemmx was not actually restarted, I was testing the reporting system. h1nds1 is a mysterious restart.

Sheila, Lisa 


Since we had lost good alignment references, and the sub-optimal IR alignment was what limited the build up in the  last full lock attempts , we decided to invest sometime working on the initial alignment procedure.

As already known, achieving a good alignment for both IR and green is easy for the X arm, but kind of tricky for the Y arm.

So, after Sheila aligned both green and IR to the X arm, we decided to commission the IR lock to the Y arm (feeding back the REFL IR signal to the MC length) with the idea that this step will become part of a future automatic alignment procedure to ensure the IR is well aligned to Y. As observed for the X arm, because of the  27 Hz and 41 Hz MC2 resonances , achieving a stable IR lock feeding back to the MC is indeed painful. We eventually succeeded by re-designing the loop so that we could keep the 41 Hz notch in the MC path always on. Phase and gain margins are not great, but this worked well enough that we could keep the cavity stably locked while optimizing BS, ITMY and ETMY so as to reach maximum build-up for IR (1 in LSC-TRY). 

At that point we used TMSY and the green QPDs offsets to recover some green build up, and we could relock the cavity on green; with both cavities locked at the same time we could find a way to keep maximum build-up for IR, and achieve 0.7 for green. Not fantastic, but probably not too bad; Keita's green WFSs will hopefully make the green alignment better.

Happy with the IR in the arms we went back to PRMI. The PRM alignment was totally off (about 15 urad both PIT and YAW); Sheila patiently brought it back, and we could relock the PRMI stably on 1f sidebands. 

We leave the IFO with the green arms locked for Keita tomorrow.

First, yesterday we had a WFS interface cable that would short circuit -100V bias to the ground. A new cable was put in (or maybe the old one was fixed), and today I restarted WFSY-ing.

I immediately noticed that WFS whitening binary IO readback doesn't agree with the output I intended to send, for all four BIO cables.

Upon looking at the whitening chassis, I've noticed that +15V power indicator LED was really dim for WFSA whitening (first picture), but when I removed the second BIO cable from the WFSA whitening chassis the LED got bright again (second picture). But that didn't solve the readback problem for that specific cable.

I and Daniel started disconnecting cables from the binary IO output chassis, and immediately the readback got sane again, and we confirmed that BIO chassis is working fine by connecting a BIO tester. As soon as we connected the cables (that connect the BIO chassis to the field rack whitening interfaces) back to the BIO chassis (the othe end of the cable is still disconnected) the readback got mad again, and the madness is somehow dependent on how we strained and wiggled the cables.

We opened the shell of the cables, and were disappointed to find that it seemed to be really easy for the exposed conductor of the flat cable to be pressed against the shell to cause short circuit (third picture).

By removing all 8 shells (four cables both ends), and then connecting the cable back to the BIO output chassis and the whitening chassis, we were able to eliminate the readback problems for most (but not all) of the requested states. This means that most of the short circuits were gone but there are still some that is not related to the short circuiting to the shell.

And the +15V LED of WFSA whitening isn't dim any more.

Anyway, for the moment, short-circuiting between high and low is a problem but not for high-high and low-low, so we decided to find a seemingly good state where the readback don't complain. For both of the WFSs, this is +33dB whitening gain, first two filters on, third filter off.

And then I connected H1:LSC-Y_EXTRA_AO_1_EXC output to the B input of the PDH CM board, locked Y arm on green, injected a sine wave to the CM board and started measuring the demod phase of WFSs. And I noticed that there are huge differences in signal levels for quadrants, and for some quadrants I couldn't make a decent job of minimizing the injected signal in one demod quadrature.

I got suspicious about whitening and measured the dark noise coming into the ADC (4th attachment, bottom), and sure enough, whitening gains seem to be all over the place, and it seems like two channels for WFSB have only one stage of whitening filter engaged. I then found that the readback wouldn't complain at 45dB too, so I repeated the same thing with 45dB whitening gain (top), and it got better for WFSA but not for WFSB. Maybe there's still some cable-related problem though I don't know how, or maybe this is the whitening chassis problem.

The next step would be to go to the floor and look at the whitening chassis. It would also make sense to see if the whitening gain for X arm is OK.