More work on the floating layer of drywall. Several of the interior roof drywall panels were attached as well.
The H2 PSL is back up and essentially where it was before the power outage. PMC and ISS are both locked, FSS is turned off due to work on servo board. We are getting 150W downstream of the PMC.
We had some issues getting the HV power supply working, it was determined that a zener diode on the PMC locking board blew, I have replaced that board with a spare.
List of relavent settings:
Note that the phase on the PMC LO will be reset to a different value when the function generator loses power. To set the phase, sweep the cavity by turning on the ramp in the medm screen. Look at the locking PD with a scope and adjust the phase until the sidebands disappear (there are LEMO cables labeled “SPARE” which run from inside the laser room to the racks outside). Then add 180 degrees to get the optimized phase.
For future reference:
Oscillator settings
Frontend settings
Pretty exciting day today. Hanford Fire Department came due to the power outage at approximately 8:40 AM It's taking a while for the system to come back to functioning status, the medm screens are not booting and neither is data viewer, the cameras work though. Full system restored at approximately 12:30 PM Waste Disposal came for cardboard Kingsoft water Contractors from Rebel Construction 3 contracting companies came for a walk-around with John W.
Mark and I just finished setting all of the face and side BOSEMs on the ITMy and FMy to nominal 50% OLV (+/- 200 counts). We also set the top BOSEMs (Left and Right) for both suspensions to account for buoyancy, as per Mark's T1100616 document. https://dcc.ligo.org/cgi-bin/private/DocDB/ShowDocument?docid=77041 The suspensions have been left suspended.
This week, we tested the damping components recently added on ISI-BSC8. These components are:
- The vibration absorbers on stage 1
- The Tuned mass dampers on the blades that go from stage 0 to stage 1
- The Viton pads under the stack mass on top of stage 2
Links to plots are at the end of the aLOG.
Vibration Absorbers (217Hz resonance)
We performed test with different thicknesses of Vitton Pads with and without the lids. These configurations (S=0.25”x0.25”) are:
- Thickness: 0.0625”, 0.125”, 0.25” without lid
- Thickness: 0.0625” with lids and pads of 0.0625” and 0.125”
The best configuration:
- Bottom pads with a thickness of 0.0625”
- The top pads thickness doesn’t seem to affect the performance.
Performance on the 217Hz resonance (the only resonance affected by the vibration absorbers):
- X, Y directions reduction by a factor of 7.4 on ST1 L4C
- RX, RY directions reduction by a factor of 7 on ST1 L4C
- the resonance is not visible on GS13
TMDs on Blades 0-1 (252 Hz resonance)
HAM-ISI TMDs were retuned at 252Hz for BSC-ISI stage 0-1 blades. Details are given in E1100963-v1. The TMDs (base) are installed at 11 inches from the post.
Performance on the 252Hz resonance (mainly visible on X, Y, RX)
- Direction X: 252 Hz resonance not visible and the new resonances created by the TMDs are not visible
- Direction Y: 252 Hz resonance not visible. One of the new resonances is at 238 Hz and 5 times lower (Corner 2 is the main contributor of the resonance in the Y direction). The amplitude reduction in corner 2 is similar to those observed in the other corners. (TF in the local basis).
- Direction RX: 252 Hz resonance not visible and the new resonances created by the TMDs are not visible
Viton pads (1"x1"x0.25") under the stack of masses on top of stage 2
- Effective on resonances at 162Hz, 180Hz and 227Hz. Measurements stop at 500Hz. More measurements are coming for higher frequencies.
Next Step:
- Full set of transfer functions (10mHz to 1KHz)
- TFs evolution with the payload (to evaluate stage 2 new resonances created by SUS)
The plots:
2012 01 06: No TMD - No vibration absorbers - No Viton pads
2012 01 25: TMDs - 3x 2 vibration absorbers (Bottom pads - 0.0625" - top pads 0.125") - Viton pads (1"x1"x0.25") 8 per stack
https://svn.ligo.caltech.edu/svn/seismic/BSC-ISI/H2/ITMY/Data/Figures/Transfer_Functions/
Comparisons/
LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_H_to_ST1_L4C_H_20120106_vs_20120125.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST1_ACT_V_to_ST1_L4C_V_20120106_vs_20120125.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST2_ACT_H_to_ST2_GS13_H_20120106_vs_20120125.fig
LHO_ISI_BSC8_Comparison_TF_C2C_ST2_ACT_V_to_ST2_GS13_V_20120106_vs_20120125.fig
LHO_ISI_BSC8_Comparison_TF_L2L_ST1_ACT_H_to_ST1_L4C_H_20111206_vs_20120125.fig
(Bubba, Chris, Corey, Hugh, Mark, Randy, Zach, with Jodi & Dale documenting)
:::: Timeline ::::
:::: The Work ::::
This week the eLIGO HAM6 ISI was slated for removal (this is due to the Chamber needing to be moved and eventually cleaned).
On Wednesday, Hugh and the Apollo crew started staging for the work (primarily by positioning the Installation A-Frames & getting other equipment ready to go). I went into the chamber to install our Trolley & Hoist Connector Blocks and to disconnect all cables from feedthroughs. With regards to cabling, some of these cables were really tough to pull from the feedthroughs; the OMC cables were especially tough, and I had to yank on the actual cable (vs. the connector) and as I did this the band came undone, and the shielding came became frayed (this cable is obviously damaged).
Yesterday (Thurs), the primary work of fully assembling the Installation Fixture around/inside HAM6 occurred, the HAM ISI was removed, and Installation Fixturing was removed. With Hugh's preparation of parts and the Apollo crew's expertise, this job went super smoothly. Tasks started roughly around 8am:
At this point it was around 11:30am, and I decided we break for lunch (vs. leave the load suspended on the Installation Fixture Trolleys). After lunch we picked back up:
On Friday, some final loose ends were completed--Mark went in-chamber to remove some conflats (for removal of the Septum plate); he also removed "Riser" hardware for the ISI (these were parts which were sandwiched between the Support Tubes and ISI Stage-0; I believe they were primarily for shimming up the ISI for eLIGO; not sure whether we still want this hardware, but Mark is bagging & tagging it).
Lots of photos of this activity is now in ResourceSpace here.
Rest in peace!
Attached are plots of dust counts > .5 microns. I have included a plot of the mode of one of the dust monitors to show when they were off-line due to the time it took to recover from the power outage.
Standoffs for the floating layer of sheetrock were installed. Several of the lower floating panels of sheetrock were attached as well. Electrical work inside the walls is getting close to being finished.
The suspension and seismic test stands have been started after the power failure of this morning.
We had a site power outage over this period:
Jan 26 08:35:48
Jan 26 08:36:08
approx 20 seconds in length. CDS systems have been recovered. We took the opportunity to swap out the old style timing master in the MSR.
Attached are plots of dust counts > .5 microns.
Keita, JohnM, DanH We did some work on the ETMY transmon suspension: clamping cables on the back face, and installing (but not tightening) the cross-braces on the front and back. Pictures attached. Before and after the clamps were applied we noted the values for the OSEMs. Things changed after the clamping, but not too badly; JohnM has the numbers if you're curious. One of the electropolished nuts for the cross-braces was malformed in a strange way, so the back brace is currently held up by seven bolts instead of eight. We noticed there were assemblies of what looked like BOSEM magnets on the suspension's first stage...perhaps for eddy dampers that haven't been installed? We also wanted to assemble some mirror mounts, but we could not find the finely-threaded adjustment screws.
Note, SUS decided a while ago (and TMS followed suit) that the ECD copper blocks would not be used at this stage. The magnets are still needed on the mass for the weight and balance (and for potential future use of the copper ECDs).
First layer of exterior drywall has been put up on the acoustic enclosure. Insulation has been brought inside the LVEA (wrapped for the moment) for inside the walls.
X1 QUAD 03 BUILD 03 Attached are plots of the X1 QUAD 03 BUILD 03 M0 & R0 TF measurements from last night along with measurements from 01/06/2012. For the M0 mass, there is virtually no change in the resonances from the two measurements, which is expected. The R0 chain, however, is the chain where the cabling attaches between stages. On R0, all DoFs except Pitch appear to have not been affected by the cable lacing. The R0 Pitch plot (pg 5) indicates the second major pitch mode has stiffened quite a bit since the 01/06/12 measurement. The DC Pitch also decreased slightly for this measurement. Cabling between the stages may be the cause of the extra Pitch stiffening on R0, so a reassessment of the R0 cabling could prove useful.
This sort of R0 Pitch stiffening is expected, and acceptable once cables are laced down the reaction chain. See discussion of similar before vs. after lacing on ITMY: LHO aLOG 1769. I'm actually more concerned about R0 Roll: The second mode (~0.85 Hz) seems to have split, or now has two couplings virtually right on top of each other. We should look into this further!
Small weld repair performed on new vacuum bake oven (VBO-D) to repair leak stemming from manufacturing defect in external stitch welds. Cleanliness was maintained including a foiled welding helmet to protect the inside of the oven from contamination and the inside of Slim's head from government mind control rays. Work done by Slim, MarkD and KyleR.
http://berkeley.intel-research.net/arahimi/helmet/
It should be noted that aluminum foil may in fact amplify government mind control rays. I propose we begin research on faraday cage or mu-metal hats.
(Corey, Jim, Vincent)
Yesterday (1/24) afternoon, Jim and I went in and swapped Stage1 Viton Shims (these are located under weights) mounted on the Access Walls of Stage1. We removed 1/16" shims & inserted 1/4" shims. Vincent will then make measurements on the system to gauge their performance. (note: before the 1/16" shims, 1/8" shims were looked at).
The work above was for H2's BSC8 ISI System, and obviously the alog above should be marked for H2 (but I can't edit that any more).
