Advanced LIGO Systems

From: Hiroaki Yamamoto hiro@ligo.caltech.edu

Modeling and Simulation (Hiro Yamamoto)

modeling and simulation (Hiro Yamamoto)

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e2e weekly meeting

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Andrew of SLU (see report below) reported his study of the vertical mode of HAM-SAS using a statespace module provided by Virginio and Valerio.

Neither HAM-SAS model nor Mark Barton's quad suspension model does not have the suspension cage effect. Mark suggested that it is an easy and good enough implementation to place a stiff box on top of the HAM-SAS table. Valerio will modify the model to include the case effect.

Mark explained the difference of the test mass chain and reaction mass chain, and the effort to make ITM and ETM suspensions same (similar).

AdvLIGO LSC/ASC design using FP arm model with quad suspension (Osamu)

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When the test mass is pushed by the length force only, pitch motion is excited due to force from the wire. In the experiment, the output matrix to OSEM should be adjusted to have no excitation in pitch motion. In the simulation, an extra force to pitch which is proportional to the length force is applied in order to avoid pitch motion. After some investigation with DC response, ratio from length force to pitch force to avoid the pitch motion for M1, M2 and M3 was determined to be 2e-3, 2e-3, 6e-3 respectively. As a result of applying these forces, cavity keeps lock longer than 100sec or more (previous ~10sec). However still lock acquisition is difficult once seismic motion is excited.

Static IFO simulation (Hiro)

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A new base class is developed to that multiple configurations can be easily modeled. FP case is done and a couple cavity is being built to study the effect of the size of BS. Hiro helped John Mirror to simulate the Mexican hat cavity so that John can use a simulation to design WFS. All tools for the standard LIGO simulation worked, except that the aliasing effect seems to be more complicated that the normal FP cavity with well defined modes. For John's purpose, the uncertainty is small enough, but this is an interesting issue to be investigated in the future.

Modeler - e2e simulation engine (Hiro, Bruce, Melody)

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Working to implement a new primitive, UserDefinePrimitive. This is an extension of FUNC_X, and allows a user to built a primitive with arbitrary inputs and outputs. Bruce is building the code by mirroring the code of FUNC_X with necessary modification. Melody is working on the modification of the shared library support routine so that UserDefinedPrimitive can be implemented with minimal deviation from the FUNC_X implementation.

Mechanical Simulation for advanced LIGO (Sany and SLU team)

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Andrew Kinchen reported on behalf of Sany who attended the PAC meeting at MIT to present his groups activity and work plan.

I ran simple models including the new mgas state space provided by V .Sannibale and V. Boschi, finding results equivalent to theirs. I have also begun the implementation of the mgas state space into a mgas and triple suspension feedback control loop, based on a previous inverted pendulum and triple suspension model. I have also continued my efforts in the construction of a rudimentary triple cavity model designed to determine the optimal feedback filter settings for an advanced mode cleaner.

Yesterday, 29 Nov, I spoke with the originators of the new mgas model, sharing my observations, and requesting port assignments details.

Future actions:

I. Finalization of the mgas triple suspension model, on the basis of specifications discussed yesterday.

II. Continuing development of the Advanced MC triple cavity in conjunction with J.Quave of S.L.U. who is working on a similar length sensing model.

ALFI : e2e front end (Melody)

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Finished the graphical implemention for the new User Defined Primitive.

Seismic Isolation

From: Brian Lantz BLantz@stanford.edu

Agenda for the weekly SEI telecon
Friday, Nov 17, 2:00 pm Eastern, 1:00 pm Central, 11:00 am Pacific time

HAM Kickoff meeting summary
Kickoff meeting went well.

Preliminary Design Review
The PDR will at HPD in Boulder on Thursday Jan 4. It will be an all day meeting. Brian and Dennis plan to be in Boulder . We hope that Ken will be able to make it, also, otherwise he will join by phone.

The goal of the meeting is to sign off on a provisional approach. Between now and the PDR, HPD will do various trades, studies, and investigations. Not too deep but "several times around" the set of design issues. This should result in a formalization of what HPD proposed to design for LIGO, and an understanding of the what and why for a viable approach. This will not be a detailed design. This will include issues of the mass distribution and access.

Final Design Review
The first part of the FDR will be Monday, April 2. The second part of the FDR will be in the week on April 16-20.

For the first part:
This should be enough information about the design that the Stiff team can prepare a case which will allow the LIGO evaluation team to choose between approaches for the LIGO interim upgrade. It should include: solid model, and useful cross-sections, confidence that the system can be built, installation/ instrument access discussion, all relevant dimensions for performance analysis, bending modes, cost and schedule estimate for manufacturing. (Note, HPD needs to know how many will be built before they can say how long/ how expensive it will be). The manufacturing estimates are not binding; they are estimates. LIGO/ HPD will work together to generate a list of particular differences between this design and existing experience.

This review will not include dimensioned drawings or firm quotes on parts.

Brian (and others) will travel to HPD for this review.

The second part of the FDR will review the drawings, and make sure that we are ready to build.

The handoff of documentation, particularly detailed assembly instructions, may happen after the FDR.

Progress on the BSC
Capacitive sensors:
4 sensors for stage 1 are broken (we started with 7 = 6 + 1 spare)
2 are due back the week on Nov 20
2 will be back in 3 to 6 weeks
Rich will watch the supply voltages on startup/ shut down to see if spikes or drops are killing the sensors. Ben will be asked to try to get us 1 more spare for both the coarse and fine channels.

Geophones
We think that all the preamp boards for the GS13s and the L4C were damaged when the d-sub connectors were connected with the wrong number of vacuum feed-through pin reversals. The cables on the prototype are now correct. Rich and Brian O say that the lock on the GS13 is working, and that the GS13s are locked.

Brian O will send a new set of pre-amps to MIT, to replace all the broken ones.

After the complience measurements on stage 1 and stage 2 are done, the sensors will all be removed and the boards replaced.

The old boards need to be fixed.

We need a channel-checker to be sure this doesn't happen again. Ben has a conceptual design for this. time to build it. Brian O will coordinate with Ben on this.

Compliance Matrix
Rich has some preliminary measurements of the compliance matrix for stage 1. He will try to finalize these measurements today, and get the measurements for stage 2 in the week of Nov 20.

Stanford Progress
Feedforward
Matt has remeasured the stage 2 transfer functions for y and rx to correctly predict the stage 2 responce in the stage 1 basis (you need x, y, rx and ry for this). Using this information the feedforward supression of stage 2 x motion between 10 and 20 Hz still doesn't work.

Seismometer
Dan C has been working to re-calibrate the 4 temperature probes. The most recent set of data may be contaminated by a heat leak from the reference thermometer. A replacement reference has been found and the calibrations will be repeated.

We've started to build a pressure sensor, and are thinking about the best way to calibrate it.

Dan Clark is trying to get another 3-day run of the seismometer next week. Then we will take it apart to make some changes in the null point, add a mirror for the short interferometric readout. Dan DeBra reminds us to get enough data that we can measure changes in stiffness and bias points when we reassemble the device.

SPI
Parts for the optical sensor and the PZT drive are almost done. The PZT stack on the mirror has quite a bit of tilt when it translates. We think this is OK, but are suprised by the poor quality of the PZT stack. A new stack may be needed.

Ground Motion History
Shang has put together a nice history of the ground motion at the obseratories over the last 2 or 3 years (depending on which sensor you pick). The data can be seen in the SEI logbook, entry 731. He is working to create a report which will explain the methods and results. We see the motion at LLO is, if anything, smaller this year than last year.

From: Ben Abbott <abbott_b@ligo.caltech.edu>
Seismic:

HAM-SAS

All of the boards for the HAM-SAS electronics system have arrived, and are either stuffed, or being stuffed. There are some parts that are back-ordered, and should arrive shortly. Their front and back panels have arrived, and most of them are now in place on the boxes for the boards. The power supplies are installed in the boxes, and many of the boards are as well. I should have a good amount of hardware to bring with us next week to install in LASTI. Some of the other boards need some extensive testing, and will be shipped to LASTI in the coming weeks.

ISI

The new GS-13 boards have mounting holes that were spaced incorrectly. In the picture, it looked like they were on 1" centers, but they are actually supposed to be on 29/32" centers. The existing board has been modified by Joe Hanson, and I have changed the PCB to fix the problem. New boards will be ordered shortly.

From: Dennis Coyne <coyne@ligo.caltech.edu>
Subject: minutes HAM-SAS 22-Nov meeting

1) fabrication status

Dennis returned from his visit to G&M -- the cleaning and cleanroom facilities are very good -- the parts are all of high quality craftsmanship -- the clean assembly protocols/practices are good (comparable to LIGO's practices)
all 4 filters tuned at < 200 mHz with tuning screws & spring in parallel

Filter	Frequency [mHz]	Optimal Load [Kg]	Height [mm]
A	192	276.21	19.46
B	180	275.42	19.95
C	188	276.34	20.15
D	180	276.45	20.0

Preparing to attach 4 filters to base plate had failure of an eye bolt! -- void found at the root of the eye and caused failure at ~10% of rated load -- fortunately no one was seriously hurt and only a minor, localized dent to a part (drop was ~10cm) -- new eye bolts from a different manufacturer are being procured

Bolted bottom plate to the support weldment

Started mounting IPs to base

Going to bake all coils, except race track coils (which arrive tomorrow) -- washed in ultrasonic at 50C in alcohol -- will bake 200C overnight

Lifting carts are mostly disassembled -- parts will go into cleaning tomorrow

Stepper motors to be baked in the small oven -- PID controller has been installed

Vertical & horiz springs for 2 configurations have arrived -- receipt of some more springs (with slightly higher and lower stiffnesses) is pending, to deal with off-nominal spring stiffness if needed

Chiara will send an email to Ed and Dennis with a request for LIGO to cover some additional costs incurred at G&M (per discussions between Carlo, Chiara and Dennis on Monday)

2) LASTI test plan

Nothing new

Pending actions:
a) Dave O.: triple suspension to be installed on the HAM-SAS table initially, or after some testing of HAM-SAS by itself?
b) Dennis: prove that air bearings are not needed on the piers
c) Dennis & Dave: draft evaluation criteria for review by the group and to see if the test plan (and simulation plan?) are complete and timely for a decision in March

3) electronics

10 Modules are being stuffed in the Wilson house shop @CIT
Panels due in next week from panel express
Next week Rolf, Alex, Rich travel to LASTI to install CDS infrastructure for several projects including HAM-SAS
Week of 12/4 Jay and Ben travel to LASTI to install HAM-SAS specific electronics and continue where Rolf et. al. finished

Jay & Ben will discuss with Virginio what electronics/controls testing can be done at CIT to compliment tests being done in situ at LASTI

Next week (Wed 11/29 at the usual time, 8:00 am PT), Jay will go over an overview of the HAM-SAS controls. See the links to some HAM-SAS documents at the top of this page:
http://www.ligo.caltech.edu/%7Ejay/documents.htm

4) Simulation

Nothing new

Suspension

From: Janeen Romie <janeen@ligo-la.caltech.edu>

LIGO SEC Kinetic Art Project (aka Wave Wall)

Working with Ed Jasnow and Allen on the final Superior Steel invoice.
Wrote up procedure for locking the wave wall and put it on the LLO wiki.

Advanced LIGO

Working on actions from last Thursday's OMC meeting. Most of the SUS weekly last week centered on the OMC. Working with Carol, Florence , Jay, Rich and others on budget and fabrication account information. Working with Chris and Calum about detail design.

Provided to Justin a table of the count of hybrid and initial LIGO type osems for all suspensions. Worked with him to update his appendix. Updated the suspensions bonding matrix.

Phil Willems is here at LLO and I'm working with him on the design of the ring heater and it's interface to the ETM lower structure. Joe O'Dell provided helpful pdfs and a step file.

From: k mailand kmailand@ligo.caltech.edu

The CES shop is modifying the fixture rotator assembly rotating plate to match the arm, and the LASTI set up.

The final set up and machining of the arm is in progress at CES; all of the purchase parts for the LASTI 'conveyor'

tooling have been ordered. I have been working on the ESD mask , and with Navitar the coating company re.the tooling requirements for their process. I'm also running a cavity beam dump FEA, to see if additional bracing is required, algor has problems solving it, algor tech support can not determine the problem, and has sent me a cd with the latest v19.3 program version to try.

From: Chris Echols <cechols@ligo.caltech.edu>

Advanced LIGO Output Mode Cleaner

Mechanical design:

• updated lower wire attachment buttons
• added "tablecloth" osem coil holder and osems
• updated intermediate mass assembly
• added blade guard, added blade mounts to structure
• updated structure design (.25" wall thickness on legs, 10cm increase in height overall, 2" wider)
• Janeen will take over blade assemblies, while I have acquired "tablecloth" design

Drawings:

• updated structure drawing

Other:

• met with M. Gerfin to discuss cost and schedule--still on track to deliver structure mid-February

Advanced LIGO AOS

No update

Core Optics

From: Bill Kells kells@ligo.caltech.edu

From: GariLynn Billingsley <Billingsley_G@ligo.caltech.edu>

The Advanced LIGO polishing pathfinder request for proposal has been compiled and is ready to go to our vendors. We hope to have this accomplished by the end of the day December first. We are asking for responses by January 19 out of a realistic allowance for the Christmas holidays. We hope to have our review committee in place before the end of December so that we are ready to work quickly and place the desired contracts.

We now have a size for the compensation plate to be used in LASTI. I am gathering requirements in an attempt to expedite procurement of this piece in time for some testing at LASTI. I sincerely doubt that we will be able to make delivery by the time the noise prototype is installed.

The various core optics meetings have been condensed into one. Nominally Wednesday at 1pm pacific, unless we get another request to change the time. Please let GariLynn Billingsley know if you would like to be included in the meeting notice distribution and are not currently.

We have sent 1" coated and uncoated optics to CSIRO that have been measured on our scatter instrument. We will ask them to address the difference in microroughness between the two samples, then to evaporate a gold coating and repeat the measurements. The samples will then be measured again at Caltech, we hope to determine if the excess scatter seen at the observatories is due to the substrate or coating.

Auxiliary Optics

From: Michael Smith <smith@ligo.caltech.edu>

SLC

I refined the scattered light noise fringe-wrapping model by incorporating a Bessel function expansion to calculate the noise amplitude at the fringe-wrapping harmonics.

I finalized the concept for the errant beam baffles. Luke Williams is creating SW conceptual models of the baffles.

I developed a SW conceptual model for the suspended arm cavity baffle. The baffle will be suspended on the HR side of the ITM and ETM, similar to the elliptical baffle, either directly from the quad support frame or from the BSC optical table, with a positional reference to the quad structure. The baffle will be made of polished, oxidized stainless steel and the estimated weight is 4.5 kg. I will send the SW file to the SUS group for their help in mounting the baffle.

I developed a SW conceptual model for the parking beam dump, which provides a safe place to put the reflected beam when the PRM is intentionally misaligned to break the lock of the power recycling cavity.

I am in the process of writing the Conceptual Design and Requirements document for Stray Light Control.

Luke Williams is in the process of testing the oxidized stainless steel baffle material with a high power laser beam in vacuum, to determine the failure mode.

Control and Data Systems

From: Rolf Bork <rolf@ligo.caltech.edu>

- Primary work this week of the CDS group has been focused on the HAM SAS controls installation at MIT. Rich and Rolf are at MIT this week. The controls racks have been dropped into place and the controls computer, I/O chassis, and DC power distribution were installed. Jay and Ben have continued work on more SAS electronics chassis and will finish up installation, field cabling and system tests next week.

- Held a couple of class sessions with MIT staff and students on how to use the CDS Matlab code generator for new CDS systems at Lasti.