From R. Abbott's log in LLO's alog:

Ok, this sort of thing is hard to describe, but I'll try:

1.  I assume the problem you are describing is associated with the flange end vacuum side cable interface
2.  This PEEK body of this type of connector is held together by several screws that are only visible with the connector unplugged from the flange
3.  The body screws I just mentioned thread directly into the metal backshell.  Here's the point of badness.
4.  If the heads of the screws stick out whatsoever, they will contact the inside metal surface of the vacuum flange.  This is probably where you are getting your grounding problem.

As for the OSEM ground, armed with the understanding of loose screws and grounding problems, I would look carefully for a similar mechanism.

See his full log in response to ground hunting at LLO:
https://alog.ligo-la.caltech.edu/aLOG/index.php?callRep=9810

The environment was still not correct for the burt scripts.  Fixed, the latest one run automatically appears to have worked.

Replaced the Ham-A Coil Drivers in SUS C4 (U7, U8, U13, U14) with ones modified as requested in E1201027.

Stefan, Sheila

This morning Stefan and I returned to the PSL.  First we adjusted the AOM alingment to improve the diffraction efficency.  In the end we measured (with the filter on the power meter) 

33mW before AOM 
27.4mW after (single pass)
24.35mW after double pass

at around 74% double pass efficency, this is pretty good now.  Stefan adjusted the efficiency of the first pass by moving the AOM (mostly in pitch) and the second pass efficiency by aligning the retro reflecting mirror.  

After this the beam looked low in the apperatures of the EOM, so we moved it down, effectively undoing what Kiwamu and I did yesterday to keep the beam centered in the apperatures.  Once we had realinged the ref cav, the beam spot on the reflected camera was again in approximately the center, but now the beam spot clearly has 2 lobes when the cavity is unlocked.  Stefan removed the ND filter on the camera to make sure this wasn't an artifact, and the lobed shape remained.  

We then double checked the ref cav power budget, now making all measurements with the filter off:

23mW incident
refl (after PBS for circulator) 21.1mW (130mV on refl PD when unlocked)
locked cavity refl PD 29mV (this means 4.7mW refl unlocked)
the dark offset on this PD is 0.8mV (measured yesterday)
transmitted: 12.2mW (trans PD voltage 1.21V)

This is a visibility of 78%, but we are still lossing 25% of the power, as we were yesterday.  

We found one gost beam, which seems to be coming from the veiwport.  This light gets onto the refl PD, and causes an offset of about 1.6mV, not really significant in our power budget.

Once we were done I moved the razor blade dump that is behind the retroreflecting mirror for the AOM back about an inch so that there was room to add an iris on the leakage beam through that AOM.  
Cheryl suggested this as a way of monitoring if the beam position there drifts.  I left the iris opened so that the beam is normally dumped on the razor blade, but when the iris is closed the beam 
is right on the center. 

I also looked with the beam leveler (the aluminum one inside the PSL that Doug Cook had made, with lines scribed on it and small pin holes.)  
The path between the PMC and the ref cav is consistently silghtly below 4 inches on that leveler, but this is probably just because a different reference was used when leveling the beam. 

[Jeff K Arnaud P]

Following the DTT round of transfer functions ran during monday on the 5 HSTS suspensions of HAM2 and HAM3 chambers, we processed the data today, and the results are plotted in the attached doc. Those measurements have been taken after the optics were cleaned up and the doors were put on. ISIs were damped, HAM3 HEPI unlocked, HAM2 HEPI locked. The first attachment shows a comparison between MC1 MC2 MC3 PRM PR2 of LHO and MC3 of LLO. The second attachement is a zoomed version of the first between 0.1 and 10Hz.

Most of the results look very good and consistent with the model, and there are only a few things to notice :

* MC1 and MC3 have an extra resonance at 0.85Hz in the roll DOF which corresponds to the first vertical mode. This feature will certainly disappear with the vertical DOF damped (to try)

* MC2 has successive poles (1.516Hz and 2.07Hz) and successive zeros (1Hz and 1.094Hz) in the L DOF, which is not something we are used to see in our TFs with collocated actuation and sensing. Though, the feature is very small, and shouldn't raise concerns.

Kyle 

Should be on Turbo at some point tomorrow 

Kyle

Gerardo 

Replacing (4) each OE check valves

Added a line to source the epics-user-env.sh file for the proper version of epics in the burt backup scripts running on script0.  The environment was incorrect and the burt backup was failing.

Here is the current status of the aLIGO SEI work at Hanford. The main updates of this week are:

- ITMX, HAM2 and HAM3 have been tested (chambers are closed)

- HEPI generic and local models have been updated, installed and tested

·         BSC1 - ITMY

o    ISI + HEPI - Unlocked, Previously commissioned.

·         BSC2 - BS

o    ISI + HEPI - Unlocked, Previously commissioned.
 

·         BSC3 - ITMX

o    ISI : Testing complete, in chamber. Report validated.

o    HEPI : Unlocked.

·         BSC9 - ETMX

o    ISI : Unlocked. Testing complete.       

o    HEPI : Unlocked, ongoing initial alignment.

         HAM 1

o    HEPI: Locked and vented.
      Low priority testing 

·         HAM2

o   ISI: previously commissioned with HEPI locked, currently unlocked, in vacuum

o   HEPI - IPS position loops and alignment offsets installed
     Locked

·         HAM 3

o   ISI: previously commissioned with HEPI locked, currently unlocked, in vacuum

o   HEPI - IPS position loops and alignment offsets installed
     Unlocked

·         HAM 4 

o   ISI: In chamber, Previously tested during assembly validation, currently locked, no suspension installed, in-vac cables not connected.
     Electronics ready, in field cables ready, in-rack cables ready. Temporary STS cables
     Model is running, and MEDM screens are available in the Sitemap.

o   HEPI: Currently locked, to be commissioned
     Electronics ready, in field cables ready, in-rack cables ready. Temporary STS cables
     Model is running, and MEDM screens are available in the Sitemap.

·         HAM 5

o   ISI: In Chamber, Previously tested during assembly validation, currently locked, no suspension installed, in-vac cables not connected,
     Chamber temporarily closed.         
     Electronics ready, in field cables ready, in-rack cables ready. Temporary STS cables
     Model is running, and MEDM screens are available in the Sitemap.

o   HEPI: Currently locked, to be commissioned     
     Electronics ready, in field cables ready, in-rack cables ready. Temporary STS cables
     Model is running, and MEDM screens are available in the Sitemap.

·         HAM 6

o   ISI: 
     in chamber.
     Unlocked, no SUS
     Mechanical adjustments complete
     Initial in-chamber testing complete, but not validated yet

o   HEPI: Locked

This falls under WP 4303.

The dust monitor code tested under WP 4287 survived the weekend. The difference seems to be running it with 'procServ' instead of 'screen'.

I made tagged releases of the tested code and updated the target directories in /ligo/lho/h0/target. The support module was tagged as met_one_227b_comp_ctrl-1.2.0 and the IOC directory was tagged as dust_met_one_227b_comp_ctrl-1.2.0. I changed the startup scripts in the target directories to use 'procServ'.

I restarted the IOCs from the target directories on h0epics.

- EX feadthrough work

- dust monitor code change

- close GV19

- install spool X in LVEA

- reinstall cryopump EX

- test stand reinstall/level EY

- X arm spool oplev piers - drilled anchor bolts

- replace  SUS and ISC HAM-A coil drivers, which are actually IO optics

- pull cables HAM6 to electronics room

Coil drivers were changed for IM1, IM2, IM3, IM4, and all offsets required changes.  This was complicated by choosing to do this change on the day we started pumping down the vertex, i.e. optics are moving due to pumpdown - choose comparisson times wisely.  Spreadsheet attached shows times used and old and new offsets.

Tyler G. Greg G.
Fabbed up some sheet metal covers for the BSC 1 and 3 viewports. These were installed to make the viewports compliant with our laser safe standards. They don't have warning labels on them saying not to be removed, so try and avoid removing them.

J. Kissel

I've gathered full sets of close out transfer functions for H1SUSPR3 (and HLTS) and H1SUSITMX (a wire-suspended QUAD). The results look good enough to proceed with pump down!

Yellow Flags:
H1SUSPR3 -- The Q of the 1st first vertical mode appears to be reduced from previous measurements of the free in-air suspension. I attach the .pdf of the raw DTT results for this DOF as well, to show that the coherence is still good for this resonance, implying a real loss mechanism. This is also noticeable on the R and T degrees of freedom as well, again only on the first resonance. But all resonant frequencies are in the same place, so the dynamics are as expected and well-behaved. In the end, we want these modes damped anyways, right? However if it is a real source of loss, then it's a source of noise. However, given that these are all the lowest frequency resonance, and it's the V/R DOFs it means that the loss is most likely on the top blade springs -- well away from the optic, so what ever excess noise is present will be filtered by the otherwise free SUS.

H1SUSITMX -- The only thing awry here is that the R0 V and R DOFs show much higher response (an overall DC scale factor) than expected. However, it was immediately obvious that this is a result of calibration filters not turned on. Taking a look, we immediately discovered this to be the case -- the "to_um" filters has been turned off for ONLY the R0 LF and RT OSEMs. They're now turned on, and we will be sure to capture a new safe.snap so this problem doesn't arise again.


All data and common scripts (with updated meas:ists) are committed to the SusSVN as of this entry.

• Lateral Error: +0.19 mm
  • Tolerance: ±2.0 mm
• Vertical Error: +1.88 mm
  • Tolerance: ±2.0 mm

Patrick, Kiwamu

This is a follow-up work of the PSL power control rotation stage (see #8606). The punch line is that:

• The rotation stage is now functional and controllable through Beckoff.
• It is ready for the installation.

This morning, we installed a +/- 24V power supply cable to enable the relay circuits for the interlock. This power cable connects the interface box, which is currently sitting on the PSL table next to the periscope (see #8606), and a LIGO-standard power strip underneath the PSL table. I confirmed that it lighted up an LED on the front panel of the interface box. Then I connected the two-pin motor power and DB15 cables at the Beckoff chasis which had been disconnected 10 days ago (see #8593) for a safety purpose. To plug them back in, I powered off the chasis for approximately a minute. Then, I powered it up again after I plugged them.

We tested the rotation stage to see if it is functional. At the beginning, because the interlock was at the disable position (the mechanical switch was in its down position), the rotation stage didn't move at all regardless of what kind of command I sent. This is good as this is how it is supposed to be. Then we switched the interlock to the enable position by toggling the switch. This then allowed the rotation stage to move. So it is working fine and ready to go.

Note that, at the moment, the rotational stage doesn't have a waveplate in it. Plus, the stage is sitting aside the main path, so it is not going to do anything for the main beam.

Attached are pictures of witness plates I installed in HAM2 before pumpdown.  There are 4" silicon wafers and 1" optics in the chamber, and most are on stage-0 of the ISI or in the beam tube, one 4" wafer is on the HAM2 table surface, near the North edge of the table.

#62 = NW corner of stage-0, showing three 1" optics and one 4" silicon wafer
#63 = beam tube North of HAM2 ISI, showing one 4" silicon wafer
#67 = W side of stage-0, showing one 4" silicon wafer
#70 = beam tube South of HAM2 ISI, showing one 4" silicon wafer
#71 = SW corner of stage-0, showing one 4" silicon wafer
#74 = HAM2 floor, under stage-0, showing two 4" silicon wafers

Not shown, one 4" wafer on the HAM2 table.


- Total number of 1" optics in chamber = 3.

- Total number of 4" wafers in chamber = 8.