Sunday evening fireworks. Manasa heard it.

 ETMX oplev qpd gain has to be increased.

 The BS and the PRM have 3.3 Hz resonant gain filters that kill the phase margins.

 Oplev transfer functions PIT UGF were optimized to be at 2-3 Hz with 60 degree minimum phase margin by adjuting oplev gains.

Additional Notes by KI:

• The PRM oplev has a tailored 3.3 Hz resonant gain in order to calm down a wobble during the lock acquisitions.
• Also in the PRM oplev a 35 Hz elliptic cut-off filter wasn't  activated at the time when Steve measured it.
• In both ITMs, elliptic cut-off filters seem to have higher corner frequencies compered with the others.
  
  • I guess these settings are from the old days.
• ETMs and ITMs have whitening filters while the rest of the suspensions don't.
  • Without the whitening filters, normally the signals above 30 Hz are covered by some electrical noises or perhaps He-Ne laser intensity noise (#5630).
    • This is why we usually use the 35 Hz elliptic filters to roll off the control noises.
  • Since the ETMs and ITMs have whitening filters they potentially can have slightly higher corner frequencies in the elliptic filters.
    • Of course the corner frequencies need to be re-designed in terms of the amount of noise injection to the longitudinal motion.
      

Koji, Rana and Steve

The floor preparation continued today. The really messy part of drilling and jack-hammering the concrete were done in controlled manner.

Particle counts peaked at 106K of 0.3 micron and 13 K of 1.0 micron particles/ cfmin at the top of SP table.

Legs were installed with the help of Koji and strongman Rana. Professor Rana was very useful lifting the 85 lbs legs. 

Atm1, Drilling holes for ribbed bar reinforcement of concrete

Atm2, Koji and Rana are playing hide and seek while installing legs

Atm3-4, 6 Rigid tripod legs attached by 6x3 of 1/4-20x 7/8 screws. The top plates of the legs were torqued to 108 ft/lbs by Rana

 Installed 0.5" ID 10 ft long protective tubing at the PSL end of the  ETMY fiber this morning. Here I had to cable tie a bunch of cables at the east side of the PSL enclosure.

They were hanging off the table blocking space were the sliding doors move.

 At the ETMX end of the X-arm fiber received the same protective tubing.

Crane balancing at the south end is continuing today.

 Little change in the AC set temp can make wonders. Neslab chiller bath temp 19.99C is back to normal and daily variation of PSL are much better.

Hi Steve -

I found the doc I was looking for:

https://dcc.ligo.org/LIGO-E1200821

Specifically, you might find guidance in Section 5 and the pictures at the end of the doc.  This should work for Vacseal as well.

Good luck - it will take some time (hours to day or 2)...
I'll be interested to know how it goes.

GariLynn helped us develop this procedure so you could also ask her to cast an eye over the setup if you are worried.

-Betsy

ps: there is no existing fixture to hold SOS optic while soaking it
 

Proposed Acetone soak dish for SOS epoxy softening.

It has good acces through 5" top ID. The set up is stable and teflon lined.

Materials: glass jar with SS cover, teflon bricks, 0.008" teflon wrapped "high density Drever bricks" and aluminum

Drever brick: I beleive it is a Tungsten alloy. We used it as vac-bat savor at the coffe can. It has high density, heavy and hard, it was never identified.

I will soak one brick  to see if it has any reaction ability with acetone.

NO means that only Glass and Teflon can be used for this fixture in  Acetone. We can not take a chance on the coating!

I guess the small surface area Aluminum dumbbell, guide rod and-or wire standoff, magnet and epoxy does not degrade the acetone such way that it effects our coating.

Not ot mention, that only the very edge of the coating would in this solution.

Glass soaking dish with teflon guides.

 Keven, Steve

1Y4, 1X1,2,3,4 & 5 instrument racks floor space were cleaned.

 Keven, Steve

1X6, 1X7 and 1X9 instrument racks floor space were cleaned today

 Keven, Steve

The floor was cleaned under the east arm tube with hand held wet towel. We moved staff around and mopped. I did at the bottom of rack  1Y1, 2  and 3. 

Last week we did the south arm tube floor.

Next week we 'd like to clean under rack 1X1,2,3, 4, 5, 6 and 7 

 The east and south end of the 40m emergency exit doors are sealed- tapped off temporarily.  They will be painted on the out side only.  This job will be done by tomorrow noon

 Do not open chamber if you smell the paint !

Building:         Central Engineering Services

Date:             Monday, 04/10/17          

Time:             7:00 AM TO 9:00 AM           

Notification:     Crane Activity

Contact:          Ben Smith, X-4190 Brad Nielsen, X-8751

Contractors will be removing the large vaporizer located on the South

side of CES. Vehicle access will be restricted due to crane placement

and operation, but there will be a single traffic lane available. This

work may create minor noise and vibrations.  

The PSL out  2" OD beam guide tube was cut  1.5" shorter to 13.5"

The 10" OD  0.25" wall Al tube was replaced by a  lighter, not anodized and thinner  wall 0.094" tube of 15.5" lenght, that is 0.75" shorter.

The new position of the PSL table made these cuts necessary.

It is posted at the 40m wiki with Gautam' help. Printed copies posted around doors also.

 ~Vancuver, Canada earthquakes: magnitude 6,  5  and more shaking

No obvious sign of damage.

I powered down 1Y1 and 1Y2 instrument racks of MC and RF-systems this morning.

Both racks, SP table, clean tools-parts boxes and MC2 area are also covered with plastics.

Bertin Bros. Construction, Inc is working on the floor preparation. Their head man is Robby Bertin, cell 626. 831.2264

Today's job:

remove tiles, clean off tile glue, drill for ribbed  steel bars, rough clean- surface for good bounding. paint floor with bounding agent

The south end door leaky weather seals replaced.

The aim is here to get some overpressure inside / outside so the lab partical count would not depend on outside condition.

All 3 cranes inspected by professional and load tested with 450 lbs at max reach.

Our 3 cranes passed  professional  inspection. Fred Goodbar of Konacrane with 450 lbs load at full extension.

Certificates will be posted in 40m wiki as they arrive.

All 3 cranes inspected by professional Fred Goodbar of Konecranes and load tested with 450 lbs at max reach on Friday, March 3, 2017

 New gear box installed and tested by Fred KoneCranes.

 Air condition maintenance will be finished by 11:30am tomorrow.

Yesterday, Kelvin mopped with chemicals the whole floor area of the  lab. This was triggered by some  visiting  ants at our PSL last week. It was 6 months since we had the last fully wet mopped IFO floor.

The cleaning- mopping water became   very dirty at the end.

These old specs are not so bad. But we now want to get replacements for the TRX and TRY and PSL viewports that are R <0.1% at 532 and 1064 nm.

I don't know of any issues with keeping BK-7 as the substrate.

Tilted viewports installed in horizontal position. Atm2

New optical quality BK-7 windows in 2001 [4 substrates ] AR coated R<0.75 % for 630-1064nm " Azury BLue" broadband : TRX, TRY, ITMY-Oplev &  ITMX-Oplev viewports.

The BS-Oplev and PRM-Oplev 10" CF with 5.38" diameter view was coated the same way. The window here is Corning 7056 Borosilicate

5 more BK-7 substrates were coated R <0.1% of 1064 nm "Golden Orange" Their location: IMC-IN, IFO-REF and OMC   The next vent we have to confirm optical quality window locations.

All other conflat flange viewports are 7056 Kovar sealed .

Technical notes of 2001 40m upgrade can be seen at LIGO-T010115- 00- R  ....page 14

The microscope shipped back to the vendor for credit yesterday.

http://www.amscope.com/3-5x-180x-boom-stand-trinocular-zoom-stereo-microscope-with-144-led-ring-light-and-10mp-camera.html will be ordered today.

The actual unit we are getting has lockable zoom for better repeatability after calibration: SM-3NTPZZ-144

Quote: CWQ6-020817

This AmScope microscope would have 3.5x-180x magnification, calibratable measurement function, 5MP picture and good working distance to work on printed circuit boards.

 To take this into account, last night, I reduced the TRY gain by a factor of 2.  This is not exactly correct - when the layout is finalized we need to figure out what the pickoff situation used to be (we think, based on the Xend, that it could have been 0.5*0.9), and do the correct normalization.

Batteries replaced in control room UPS after 3 years from replaceUPSbattery.com

Replaced the batteries successfully in the control room.  We just had to switch the clips from the old batteries to the new one, which we didn't know was possible until now.

 Pitch damping solution needed! It should be in the machine shop already.

Measurements for good fit were made. The new shelf will be installed on next Tuesday at 2pm

The reference cavity ion pump is in the way  so the cavity will be moved 5" westward. The shelf height space will be 10"  Under shelf working height 18" to optical table.

While moving the RefCav to facilitate the PSL shelf install, I bumped the power cable to the AOM driver. I will re-solder it in the evening after the shelf installation. PMC and IMC have been re-locked. Judging by the PMC refl camera image, I may also have bumped the camera as the REFL spot is now a little shifted. The fact that the IMC re-locked readily suggests that the input pointing can't have changed significantly because of the RefCav move.

Johannes informed me that he touched up the PMC REFL camera alignment. I am holding off on re-soldering the AOM driver power as I could use another pair of hands getting the power cable disentangled and removed from the 1X2 rack rails, so that I can bring it out to the lab and solder it back on.

Is anyone aware of a more robust connector solution for the type of power pins we have on the AOM driver?

ETMX sus damping recovered.  PSL enclousure is dusty at 20V rotation speed. Rainy days as outside condition.

I think we can put ø2mm × 10mm long magnetic material inside 4 holes with actuation magnets. Then magnetic field on the other side of the mirror will be close to one produced by actuation magnet. Magnetic cylinder center of inertia will be in the vertical plane where mirror's center of inertia is. So this should not change alignment significantly. Eddy current dumping will be applied to the end of the magnetic cylinder opposite to the magnet using aluminium disks, we have them in the clean room.

 I've tested this approach. As we do not have required cylinders with high magnetic permittivity, I replaced them with magnets simular to actuator magnets ø2mm × 3mm long. Using them and aluminium disks from other TT I've made a "pitch dumping" construction.

Pitch Q reduced but not that much as I could expect. I did a ringdown test. 

Plots:

yaw ringdown using original construction     |  yaw ringdown with added pitch damping

------------------------------------------------------------------------------------------------------------------------

pitch ringdown using original construction   |  pitch ringdown with added pitch damping

 From this data I've estimated Q factor for yaw (135 vs 88) and pitch (192 vs 77) (original vs added pitch damping). Thess results diverges with the ones obtained by designes. They measured Q~40-50 for original construction. Pitch and yaw have 2 close resonances so this time domain method can not be very precise. I've measured the same with SR785.

In these comparison plots excitation was not the same as coils are not plugged in yet, but resonance Q factors can be compared.

 I've made a more precise measurement of pitch damping using spectrum analyzer.

Measurements confirm that damping using small actuation magnets reduces pitch Q by a factor of 4 and is not enough.