it seems like the ref cav alignment is still bad.  Trend attached, there was a power glitch 9/30, ever since the ref cav trans power has been dropping although the PMC trans has been steady.  

This is sheila, Sorry I'm logged in as Joesph areeda

Trying to adjust for the misalignment that Jason saw RichM and myself tried to move ETM-X to correct.

Initial Dial Indicator readings:

We tried to make a move 3mm W and 1mm Down. As well as a 940μr rotation CCW, as per Jason. 8126 8116

This may not be as much of a swing west as we need, and the rotation amount was a bit of a guess. Getting another IAS shot at this point will help us to fine tune the alignment. 

Started M0 and R0 undamped ETMX transfer functions

This is an entry that I was supposed to write some time ago but I never did..here it is, "Kissel style".

Problem : Keita  found  a couple of weeks ago that the mode as measured after the REFL WFS telescope in HAM1 was not what expected, and that mode, propagated through the REFL WFS sled, would give 35 degrees Gouy phase separation between the sensors, and even less between the tip-tilts actuators. Very bad. Sheila had to move the tip-tilts to compensate for that. We were puzzled because the mode as reaching HAM1 from HAM2 was not very far off from what expected (Paul's calculations, same entry), the telescope lengths were close to nominal, the sled was built according to the "nominal" design..everything was close to nominal, but somehow we ended up very far from the 90° Gouy phase separation we wanted.

Short version of the story: My best guess, based on the alamode model attached, is that all these "small" variations from nominal are indeed relatively small, but they all add up together to create the badness that we saw. My alamode file is attached.

Long version of the story

*All "nominal" parameters as designed:

Gouy separation between RM1 and RM2 is 66.5778
Gouy separation between WFS is 89.7558°

*Adding as built REFL WFS sled

Gouy separation between RM1 and RM2 is 66.5778°
Gouy separation between WFS is 68.0585°


* Adding as built REFL WFS telescope

Gouy separation between RM1 and RM2 is 56.7438°
Gouy separation between WFS is 66.3777°

*Adding as measured input beam parameters in HAM1, before the REFL telescope

- Horizontal

Gouy separation between RM1 and RM2 is 55.6327°
Gouy separation between WFS is 56.3534°

- Vertical

Gouy separation between RM1 and RM2 is 49.9092°
Gouy separation between WFS is 50.4782°

*This is still not quite as bad as Keita measured, but between the uncertainty on the mode measurement after the TTs and the tolerances on the ROC
of the curved mirrors (it looks like we are indeed sensitive to variations from nominal of the +1.7m mirrors), we might be quite close to explain what we saw.


The message : No major problem, small things add together to make big things, need to measure the beam before and after the telescope to (hope to) get this right. 
 
Additional message : The current REFL WFS telescope gives us 90° Gouy phase separation by having one of the WFS at the waist. I don't think this is really what we want: the beam size on the WFSs is different by a factor of 3, and having one of the WFS at the waist makes us more sensitive to errors in our measurements/calculations. Not a problem in the near future, but we might want to keep this in mind for when HAM1 is open again. I will see if I can find another solution similar to the "design" one.
 

Over the last few days I've been taking some passive noise spectra of the ISI-CPS on HAM6 to try and determine what the best grounding strategy is (Jeff made a nice cartoon of the options in T1300871).

Along the way I found out a few things

  1) The HAM 6 CPSs had two problems that canceled each other out

                 There as a master in each crate  (the box near the chamber that hold the CPS controllers)

                 and the cable which brings the sync signal from the power board was either bad or plugged in backwards (it isn't keyed)

                I tunred one of the masters into a slave and replaced the cable

  2)  All of the racks that I have tested have there chasis grounded, so placing them on a cable tray creates a ground and possible ground loop.

  3) Currently it is pretty likely that ALL of the CPS that are installed have grounds in the electroncs room rack AND at the chamber (Ground Loop Gaore)

  4) The resistance to ground from the power cable ground to the chamber is 0.6ohms

  5) the sync cable carries a ground from one rack to the next

 After fixing the problems I took spectra under three conditions

   Multiple grounds (electroncs room and chamber) these were bad

  Single ground in the electronics room, red and green lines in the attached png (clean room on/off are the differences)

  Single ground at the chamber, blue lines in the attached png

   Given that set of data i think that we should plan on converting to a single ground at the chamber.

   The attached pdf shows one spectra converted to m/rthz and the expected noise (we have measured something close to the expected noise on the bench for every unit in use)

  I don't really know what to say about this except yuck

(Stefan, on Jeff's computer)

The FSS wasn't locking anymore, because H1:PSL-FSS_TPD_DC_OUTPUT fell below the threshold value of 0.5V. Attached is a 90day trend of the  H1:PSL-FSS_TPD_DC_OUTPUT and H1:ALS-C_FIBR_INTERNAL_DC_POWER. Both channels thow the same trend, i.e. the power loss is real.

For now I lowered the threshold to 0.4V.

• Pitch: 635 µrad down
  • Target: 360 µrad down (actual req. pitch is 8 µrad down but we have to correct for the First Contact on the optic to the order of 352 µrad down, leaving a total desired pitch of 360 µrad down)
  • Tolerance: ± 10 µrad
• Yaw: 940 µrad CW
  • Target: 0.0 µrad
  • Tolerance: ± 10 µrad

With the pitch only off by ~300 µrad after simply releasing the optic, no rough alignment is needed.  Now I need to correct the position errors from alog 8116 (no change with the suspension being free) along with the above yaw with the SEI crew.  Once this is done and SEI can finish final ISI payload and balancing we will fine align the ETMx pitch.

The REFL(AIR)_A_RF9 I&Q readback cables which are pacthed into the whitening chassis were installed.

Jeff B will take the ops chair this afternoon.

** We've started strip tools on a TV screen and on an ops workstation screen to monitor the pair of vacuum gauge readouts on both ends of the X1 arm section (between the CS and MX) where insulation is coming off.  These are the PT-343 and PT-144 cold cathodes. 
** Hugo will make remote measurements on HAM3 this afternoon.  We're not aware of other HAM3 work that would conflict with this.
** Filiberto worked on ISC cabling in the racks near H1 PSL this morning.
** Gerardo and Thomas have been working on the ACB at the LVEA test stand.
** The ETMX and TMS speedometer needles noticed Betsy's entry into the chamber at EX.
** Intermittent dust alarms in the low hundreds (3um) have occurred on the vac prep and diode room dust monitors through the morning although it seemed that people were not in these spaces.

Last night at about 7:45, Rich and I moved the beer garden dust monitor into the BSC3 clean room, which had no dust monitor.

[Betsy Travis Arnaud]

Today, since BSC2 chamber was accessible, we checked the polarity of the four magnets located on the second mass (M2) of the beamsplitter with the electronic polarity tester.
As we were expecting (see 7693), three of them were flipped (UL UR LR), so Betsy reversed them as in E1100108.

Also, we took the serial numbers of the 10 bosems. They are referenced in the updated chart in E1200343

Attached are some nice pictures of ITMX ETMX BeamSplitter and the baffles

To reproduce the 2.8 problems seen on H1 today, we reconfigured the /etc/init.d/mx_stream startup script to only use card0 10GE card on x1dc0. Front ends still have unique end-point identifiers (line number in rtsystab file), but are now not split over the two 10GE cards. Once this was done the DAQ data problem seen on H1 was reproduced on the DTS.

We (Cheryl, Corey, Keita) have been cleaning HAM6 in-chamber optics for a while and finally we've pulled first contact today. Most of them were beautiful but one of 2" high reflectors, E1100048 SN 1042, was rejected because it had two major defects at about maybe half diameter.  The first picture shows the entire mirror surface in which the ring structure is apparent. The second is just a zoomed-in view that shows both the ring and scratch/dig next to it.

Right after pulling the first contact the ring and scratch/dig were both visible without any special lighting. Since I wasn't able to move them by a gentle pushing using a wipe, and since they were close to center, a second coat of first contact was applied, but nothing changed. After pulling the second coat, methanol wipe was attempted, which removed  some residual first contact and made the scratch/dig thing less visible. The picture was taken after wiping.

Prior to this inspection, nothing touched the mirror surface in the cleaning process except for barrel wiping and first contact application, and it's not clear if the defects existed prior to cleaning.

As ETMX comes to life it is timely to remind everyone that the IOP Sus Watchdog on that system is AC triggered only. The DC component has been removed. I've attached a snapshot of the h1iopsusex model 

Insulation Removal crew at X-arm
Work on PSL rack (DC power distribution) – Filiberto
 H1 RCG upgrade – Dave B.
Cable work at TMSX and End X - Corey
ACB work ( ITMX pacing item )  at LVEA – Thomas/Gerardo
Witness plates work in BSC1/2/3 at LVEA - Betsy
BSC9 mostly rebalanced – Jim W.