Graphic provided by C. Akutagawa.
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The LIGO Executive Committee
Agenda for Monday June 12, 2000 will be:
(Meeting time: 10:30 am Pacific Time)
Open meeting 10:30 - 11:30
Special Items: Continuing
Operations Proposal, FY 2001 Operations Work Plan, LIGO II Proposal, Publications
Policy
No report this week.
WBS 1.2 LIGO Operations--Administration
From: Ed Chargois <chargois_e@ligo.caltech.edu>
Someone cut the chicken wire to break into a storage area in the sub-basement over the weekend and made off with some computing equipment with an estimated trade-in value of between $500 and $1500.
Assisted the Technical and Engineering Support Group (D. Coyne) with the packing and shipping of two Sigma Lab Data Acquisition Units w/ cables, documentation and Software, SN# 11101 and 11107 to MIT (S. Richman), account number P158131.
Assisted the Detector Group (M. Smith) with the packing and shipping of the APS Telescope Hardware to the LIGO Hanford Observatory (B. Weaver), account number P96937.
Assisted the Detector Group (M.Smith) with the packing and shipping of the APS Telescope Hardware, COS Faraday Isolator Assembly and Viewport Beam Dump to the LIGO Livingston Observatory (J. Kern), account number P96937.
Assisted the Detector Group (M. Smith) with the packing and shipping of the COS Alignment Instruments to the LIGO Livingston Observatory (J.Kern), account number P96937.
Assisted the Seismic Isolation Group (R.DeSalvo) by arranging transportation for a counterweight to MINUS-K (Brian) of Inglewood, CA, account number LIGO.00002-3-NSFLIGO.504800.
Just a quick reminder again that I will not be in the office tomorrow, June 9th, so the DCC will be closed for the day.
From: Esther Cunningham <esther@ligo.caltech.edu>
Press here for ACCOUNTS PAYABLE HISTORY DATA.
From: "Brambila, Ruth" <Ruth.Brambila@caltech.edu>
The policy for long-term visitors to the sites is nearing completion, with the required forms for visitors now on the web. The remaining policy issues concern what facilities and resources will be furnished to the visitors. The LIGO Project has been designated as a pilot for use of a credit card for travel and entertainment. Functional specifications are now being developed for use in the creation of a software module which will be used with the current P-card application. This application is anticipated to go into effect in about one month.
From: torres <torres@ligo.caltech.edu>
For I. Petrac did change order No. 10 to Galli & Morelli, change order No. 7 to CRDF-Russia, change order No. 1 to Crystal Systems, and obtained Oracle requisition numbers for all.
For P. Lindquist prepared the FedEx to send to the NSF the revised Data Analysis Systems H/W Procurement Plan. Spent some time on travel documents. Site trip updates. P-card activities, chased voices and did reconciling.
Obtained Oracle numbers for requisitions while D. Lloyd on vacation. Unfortunately Oracle would not accept certain Poetas, among them an account for the Visitor Program. Oracle displayed the error message - "AP-19269: The expenditure item date is not within active dates of the task," or "the expenditure item date is not within the active dates of the project." Contacted F. Kaufman for help with the dilemma. Florence discovered that when they (Acquisitions) changed the end dates for the projects, they apparently did not also correct the end dates for the sub-tasks. They must now go through all the LIGO accounts to make sure that the end dates are corrected.
Graphic provided by C. Akutagawa.
From: Dorothy Llyod <dot@ligo.caltech.edu>
Report for two days (Monday and Tuesday, not here on Wednesday): Focused on processing receiving and approving the invoices on-line, which came in while I was away on vacation. Had problems entering requisitions in Oracle on Tuesday. Oracle would crash every time I would attempt to approve a requisition (Gina also indicated that she was having problems with Oracle). Needless to say, incoming reqs were not processed. Jim has been out on Jury Duty.
From: Irene Baldon <baldon@ligo.caltech.edu>
Worked on preparing the paper work for 14 new trips taken recently or upcoming (14 Payment Requests and 14 Advance Requests). There are approximately an additional 7 new trips in various stages pending completion of travel arrangements before the paper work can be completed.
I have completed all of the travel arrangements needed for 23 incoming SURF students, some of which will be coming from Europe. We have 14 students coming to LIGO/Caltech, 3 will be going to LIGO/Hanford, and 6 will go to LIGO/Livingston. I have ticketed some of them and have agreed on allowable driving costs for a number of others. We have one student coming from Warsaw who required an additional Visa so that he could layover in Zurich for one night. This has been accomplished and all is in place. Some of these students have already started arriving, especially those assigned to Riccardo DeSalvo, and the balance will arrive next week.
Completed 15 Expense Reports, some of which were extensive, involving 2-3 or more pages each. There are 24 Expense Reports still to be done. I'm not holding any completed Expense Reports which require a check from the Traveler before sending to Travel Audit to clear at the present time.
Rita continues to try to fit into her schedule some time for travel. She has taken 8 Expense Reports to be done this past week.
I spent most of Wednesday afternoon with Criselda Rodriquez-Brodeur, P-Card Administrator, to discuss what software/programming requirements LIGO will expect/require for the planned Travel P-Cards. Criselda and her assistant were surprised how much needed to be looked into and took many notes on LIGO/Federal requirements. I also brought noted several other factors to her attention that somehow no one had thought about. We will be meeting again soon to go through much more that we were not able to get to yesterday. It is my understanding that LIGO and Development will be the test cases. Criselda told me that there was no comparison between LIGO and Development, more than day and night.
Prepared the Travel/Vacation Itinerary for the Week of June 5, 2000. Performed normal recording and filing associated with Travel and Reimbursement and worked on several problem issues with Travel Audit. Also performed miscellaneous duties as requested by various members of the LIGO Project here at Caltech as well as from members of the staffs of each of the two (2) sites. I continue to do MIT's travel to the sites for installation activities and also to assist them wherever possible.
Progress Period from 6.2 to 6.8
Accomplishments (6.2 to 6.8):
The following change requests have
been submitted:
| CR-990028 | WBS 1.1.3 | Beam Tube Enclosure Closeout | F. Asiri |
| CR-000005 | WBS 1.2.1 | Upgrade Pre-stabilized Laser | S. Whitcomb |
| CR-000006 | WBS 1.2.1 | Re-polish Core Optics Components | S. Whitcomb |
| CR-000007 | WBS 1.2.2 | Replacement of Optical Lever Lasers | S. Whitcomb |
| CR-000008 | WBS 1.1.4 | Cameras and Projection System at LIGO Livingston Observatory | F. Asiri |
| CR-000009 | WBS 1.1.4 | Cameras and Projection System at LIGO Hanford Observatory | F Asiri |
| CR-000010 | WBS 1.2.2 | Redesign Suspension Controllers | S. Whitcomb |
| CR-000011 | WBS 1.2.2 | VME Development System and Spares | S. Whitcomb |
| CR-000012 | WBS 1.2.2 | ASC/LSC Rework | S. Whitcomb |
Copies of these change requests have been distributed to memebers of the LIGO Change Control Board (See LIGO-M000176-00-P).
Press for the latest Contingency Needs Projection.
From: Kris Duncan <kris@ligo.caltech.edu>
No report this week.
Announcements:
--------------
(F. Raab)
The big news this week is the delay in the task of installing resilient
flooring in the LVEA, after we had fine tuned our schedules around it.
We have no real option to fine tune the contractor, but we will push for
a greatly accelerated installation schedule once installation begins. Work
has proceeded to ready the laser and mode cleaner for the Michelson work
and investigations of PSL microphonics are ongoing. It appears that the
expected effect due to the fluctuating air pressure in the pre-mode cleaner
is there, but larger effects are caused by some optical mounts.
John Zweizig has been visiting for work with Daniel on the Data Monitoring
Tool. He has also been coaching some of us on how to get initial results
with DMT. Thursday (Jun 8) he gave an introductory session for our staff
in the control room. In approximately 2 weeks, Julien Sylvestre will install
his transient analysis software onto Sand and he also intends to do some
training sessions.
Two of our three SURF students have arrived and are fast at work coming up to speed on their projects.
Hugh and Corey are working actively on the in-vacuo seismic isolation
transfer function for the BSC in EX. This job is more challenging than
we thought it would be, since the arbitrary waveform generator from Daniel's
excitation is not working yet in this station.
Optics:
---------------------
(D. Cook)
The optical lever laser diode output powers have been reduced to reduce
internal heating in hopes of promoting a longer life span for the laser
diodes. They were also reset to 'zero' once again and will be recalibrated
using the DAQ system. I will post the numbers on the e-log when completed.
We have been taking parts inventory, staging componets and equipment
for
the up and coming 4K installations. We should start assembling COS
telescopes, transmision monitors and aligning them soon.
We should have the new actuator brackets and PAM screw assemblies next
week.
No report received.
All activities reported elsewhere
All activities reported elsewhere
| Installation:
Livingston |
Commissioning:
Livingston |
Other
Science/Engineering
Activities |
A set of new rough cut PMC bodies, that have some minor mechanical modifications related to the mounting of the body, have been received by the manufacturer. Completion is set for mid-July, when the new PMC for LLO will be fabricated at the site.
By late tomorrow, we should be starting the end stations. The auxillary systems (which run oplevs) are already in place, with some field cabling to be completed. The ISC front end controllers will also go in, but we are short timing control and fanout modules (presently in fab and will not arrive before we leave). We should however be able to complete the wiring and test the reflected memory links to these systems before we leave.
Bottom line, with some of our modules still in fab, the system will not be fully operational when we leave on Friday. However, the system should be fully tested (using the test modules and GDS) and just require plug in of these final modules when they arrive (2-3 weeks for the last ones).
The APS beam dump parts were shipped to LHO for cleaning and baking.
APS/PO Telescope optical train parts were shipped to LHO for cleaning and baking. Betsy is sending 2 2in steering mirror mounts plus one shortened mounting post for the Faraday Isolator steering mirror (all class A parts) to LLO.
Integrated layouts of the COS asemblies in HAM3, HAM 4 and BSC1/2 have been completed. The layout of HAM2 is pending.
Miscellaneous assembly and alignment tools were shipped to LLO for air-baking. Two COS autocollimator assemblies and accessories will be shipped to LHO by 6/9. Alignment targets for directing the PO mirror beams onto HAM3 and HAM4 were built and will be shipped to LLO by 6/9. 2 missing mirror assemblies for the HAM viewport alignment fixture are being sent by Betsy to LLO.
Lee Cardenas
- Arm Cavity Baffle parts
staged
completely with hardware inside the clean room enclosure and ready for
assembling as soon as I get the two middle parts and some more hardware.
- AC Baffle external support
cage staged completely with the hardware ready for assembly.
- IO Baffle staged semi-complete.
Missing parts will be available at the end of the week.
- PO telescope, Started
gathering all the parts for staging on going.
- Helped on cleaning the
rga failed IO baffle parts. Still more parts to be cleaned for the next
load.
These measurements did not provide a "smoking gun", but did help solidify the picture of beam jitter as being due to the mode-mixing caused by the PAM magnets, used here but not at Hanford. Beam jitter is seismically driven, and is coherent with OSEM signals, so appears to be really generated by seismically driven mirror motion. OSEM signals are not dramatically bigger at LLO, but beam jitter is. The excess beam jitter is concentrated at frequencies where the rigid body modes of the mirrors lie. There appears to be every reason to believe that removing the PAMs will substantially reduce the beam jitter, and should leave it comparable to the spectrum seen at Hanford.
We installed one of the new
rigid mirror mounts (designed by Jonathan Kern) on the PSL table, and compared
its mechanical response to that of a Newport mount. It is much stiffer,
with a first resonance frequency of about 1.6 kHz. It was very easy to
install. It looks like a reasonable way to substantially reduce the
acoustic pickup on the PSL-IOO table. We intend to install more during
the upcoming installation period.
Six of the mounts have been
sent to Hanford.
We measured how the mode matching into the mode cleaner varied with the light power going through the EOMs. (Light into the mode cleaner itself was kept at levels that would allow the cavity to lock.) There was indeed a slight change in visibility as the power was raised to 2.1 W, with visibility moving fromo 0.95 to 0.96.
After the vacuum system was vented this morning, we measured the shift in optical length of the mode cleaner. To better than 1%, the shift agreed with what we would expect from the index of refraction of air. There is a small drift (in the third significant figure) that we are tracking tonight and tomorrow morning. After that, we surrender the system to the installation process.
Sany, et al. measured the throughput (transmission) of MC. When the visibility (power coupling into MC measured by the fringe in reflection) is 97%, the transmission measured as the ratio of the power at the transmission viewport (of HAM1) to the power at the reflection viewport (of HAM1) is ~70%, but this is hard to believe given that the cavity resonance width appears to be at spec. For this calculation, we used the transmission of a spare SM (steering mirror) that we measured previously. During the installation period starting now, we will attempt to measure these parameters better, so that the throughput can be pinned down.
Rich Abbott
Continuing construction
of production AM stabilization circuits for the RF Distribution System.
Three units have been completed so far and are soon to be shipped to Hanford.
Running and testing the FSS in the Lauritson Lab with goals on enhancing robustness at the UGF
Peter Fritschel, Janeen Romie
Preparations for assembly
of the new osems continues. We received the 1.06 micron-blocking filters,
and have begun to measure their transmission at 1.06 micron, and have worked
out a method to dice up the 1"x2" plates into small pieces that will be
mounted over each photodiode. We are currently working on methods to fix
the circuit boards that carry the active devices in the osem head, as well
as a method to fix the filters to the boards
Prepared for design review 6/7.
Upgrades to the DAQ however have slowed me down in incorporating the acquisition mode software into the LSC system. This is because we only have enough VME parts at Wilson to run either a DAQ system or an ISC system, not both, and I had to keep the DAQ setup together to allow Alex and Hongyu to develop/test their code. I did receive email today though from Alan that he is now ready to part with our DAQ equipment in the 40m lab during construction, so that will help in the near term. I have also started ordering some parts to stay with our development system for future needs.
John Zweizig
This week I have been been
trying to get the last few improvements into the DMT software before calling
it a stable version. The latest improvements are mostly items which involve
interfacing to people here at LHO. These include:
1) Adding functionality and fixing bug to facilitate communication with background process. This code was also modified (extensively) to allow compilation with the solaris "CC" compiler. Daniel is using this interface and has already sucessfully retrieved data from a running monitor and plotted them using a GUI based on the one developed for the diagnostics test tool.
2) Adding an Epics interface to generate alarms from gds triggers. A prototype interface consisting of three sets of epics channels to contain alarm signals, time stamps and message text for each of four priority levels has been implemented by Dave Barker. These can be viewed from the operations consoles with a GDS alarm summary panel. I have written a script file to set the alarm channels and am currently modifying the trigger manager to generate alarms from triggers.
This week we fixed some minor
problems with our OSEM controllers, aligned
our laser to the suspended mode cleaner, and
locked the mode cleaner to the
laser. The lock was done in air, with the
polarization of the beam rotated
90° to reduce the finesse of the cavity and make lock acquisition
easier.
Acquisition was very prompt, and the lock was quite stable.
We estimated the finesse
of our mode cleaner with the polarization rotated
two ways: First, we measured the transmission of a witness sample,
a mirror
coated in the same run as the one that did our mode cleaner optics,
and
calculated the finesse from that. Second, we placed large sidebands
(high
modulation depth) on the beam and allowed the mirrors to swing with
only
local damping on for length control. We were then able to compare
the
width of the transmission peaks to the spacing (in time) between the
carrier and the sidebands, which when combined with the free spectral
range
gave us the finesse. Both methods gave a finesse of around 500
for
p-polarization. Recall that the finesse for s-polarization was
found to be
about 5,000.
No report received.
Matt and Luca worked together to study the misalignment effect on
the locked state of the recycled Michelson. The length control seems
to be working fine when the recycling mirror or input test mass are
rotated by less then 1 micro radian. The study has just started and
the
detail study will continue.
Biplab traced a bug causing the divergence of the cavity power and it
seems it is solved.
adlib
Hiro keeps working to convert the code to fully stl based, which is
estimated
to take around 2 weeks.
alfi
Version 4 is now used by more people and well accepted. Bruce has fixed
problems tracing which files are to be saved. A new version will be
released
soon which includes various fixes include the file path display of
modules
and this dirty flag tracing.
LLO
Biplab visits LLO this week and updates e2e on their computer. He
interacts
people to discuss about e2e. One case is that Biplab and Anthony work
together
so that the lock acquisition simulation can be done for LLO IFO when
necesary.
ALPHA machine test
e2e softwares have been successfully compiled and run on DEC-ALPHA linux
machine.
The program can be compiled with very minor changes - not machine
specific, just
more strict in some case. Both GUI and simulation engine worked. The
speed
of the simulation was tested and roughly factor of 2 faster. gcc
compiler and dec compiler
are both used with different optimizations, but no big difference was
observed.
The underlying LDAS libraries are introducing several
new problems within the LDAS APIs. The metadataAPI is
core dumping and the name attribute for ilwds are not
being passed through the sockets. This showed up some
time between the implementation of a new version of
the C++ compiler and the addition of a new attribute
in the ilwds. The problems appear to be related but
replacing the compilers and rebuilding LDAS is an all
day event. We will need a few days to isolate this set
of problems and take the necessary corrections.
The controlMonitorAPI is maturing nicely with new sets
of features to allow secure remote analysis of process
behaviour now implemented. The mpiAPI has been brought
up to the same standards for communications as those
found in the wrapperAPI. The ILWD library now has two
new datatypes supporting single and double precision
complex data.
The wrapperAPI is now able to carry out load-balancing
at the request of the mpiAPI. This completes the LDAS
side of the original work scope for the wrapperAPI and
it is now ready to load and run shared objects. We are
waiting on a version of the hierarchical search routine
from the UWM group to test in the wrapperAPI. In the
mean time documentation will be improved. There is an
issues with the computational model of the dynamically
loaded shared object which we are presently pursuing a
better solution than the one available in the wrapperAPI.
The dso from UWM is really based on a distributed compute
model and not a parallel compute model. Carrying out the
dynamic load balance is not possible within this model
and we are looking for ways to make the search algorithms
more parallel allowing for such load balancing. This is
not a problem within the current model of the wrapperAPI
as it supports an option to disable load balancing and
effectively turn the parallel analysis into a distributed
analysis so there is no schedule delay to support this
search paradigm.
We have spent the bulk of this week studying the memory
usage of the FFTW library. A few weeks ago the group that
is working on the dataConditionAPI identified that this
library is using roughly 5 times more memory that could
be explained. It seems that this is coupled to how the
plan for performing the most efficient FFT on the particular
hardware is generated. By requesting the library to make
its best plans we would need to double the cost of the
dataConditionAPI support hardware in memory. We will be
looking at this problem to see if the use of less than the
best plans can be used efficiently within existing memory
budgets.
Anderson + Rashad(LDAS SysAdmin):
The loaner E450 from Sun has been repaired after replacing the mother
board
and all 4 cpu's.
A loaner quad-fast-ethernet board has been shipped from Sun to help
with
the LDAS network and RAID performance tests.
An HPSS account has been set up for Louisiana Tech University and
Natalia Zotov identified as the password holder.
Diagnosed/repaired non-operating loaner Sun 450 with Sun engineer.
Configured Foundry switches with Foundry Engineer.
Migrated db user ldaswa to ldasdb.
Setting up db2 error logging.
Performing backup.
Testing AIT-2 tape drive under Solaris 8.
Lazzarini:
[A] I am working with a JPL contractor (J. Klohoker)
who did reliability analysis for LIGO two yeasrs ago. He will be building
a reliability analysis tree for LDAS critical components.
He has started the job (max 4-6 weeks of part-time effort):
- Continued to refine system tree for LIGO Data Analysis System (LDAS).
- Met with Albert Lazzarini on 5-Jun-00 and identified
the specific hardware
associated with the three LDAS Operating Modes. Based upon this
discussion,
the structures of the Reliability Block Diagrams were developed for
LDAS
Operating Modes 1 and 2.
- Initiated search for vendor reliability data.
Specification sheet for StorageTek's Timberwolf 9740 Tape Robot System
lists
a 70,000 Operating Hour Mean-Time-Between-Failure (MTBF) with a 0.5
hour
Mean-Time-To-Repair (MTTR). Since LIGO will utilize maintenance
contracts
to support repair activities, Albert Lazzarini and I mutually agreed
to use
a 24.0-hour MTTR for LDAS availability modeling purposes.
- PLANNED ACTIVITIES:
1. Continue LDAS Reliability Modeling/Block Diagram effort.
2. Continue search for vendor reliability data for LDAS hardware.
[B] I have started putting together a manpower plan and associated travel plan for LDAS build-up over the next 18 months. Once the LDAS group has ironed out all details, I will contact each site head to coordinate the activities by site. The peak of the activity will be Dec2000 - Apr2001.
[C] I have officially transmitted the revised LDAS Procurement Plan to NSF for review and approval.
MIT:
Working on getting the computer room moved to another location in-order
to
accommodate new servers.
Livingston:
Working on setting up a new server with Solaris 8.
Hanford:
Ordering another FORE box to accommodate additional workstations on
the network.
CIT:
Upgrading the OS on the SUN units in the 40M.
Preparing a new disk system to replace and increase the size of the
existing
home storage system.
Working on the logistics to accommodate network connections from DSL
and
cable-modems that users are having installed at their homes.
From: kells@ligo.caltech.edu (Bill Kells)
1. Begin to spend a lot of effort trying to come up
to speed on the LIGO II configuration and related issues.
2. Long on hold project (with Jordan) to measure
birefringence of M orientation sapphire mirrors.
And we have interesting results already this week !
3. Discussions with Kip, et al on how to effectively
increase LIGO II beam sizes (to ameliorate "Braginsky
noise")
From Peter Fritschel
o The web page for the LIGO 2 systems requirements meeting at MIT on
18-19 May has been finished; it now contains a summary of the meeting,
the viewgraphs of the presentations, and strain sensitivity plots and
model parameters for the current reference designs.
From: Sam Richman <srichman@ligo.mit.edu>
Stiff isolation system (S. Richman, J. Rollins, S. Chatterji)
Shourov has finished constructing 12 channels of forcer current drivers,
and has verified their basic operation. The power transistors were
getting too hot at high inputs, so he is making a better cooling scheme.
Jamie's setup for logging multiple channels via the dSPACE system works,
though we are still puzzled by what seem to be noisy results from the transformed
data. Meanwhile, he has recorded some of the more important transfer
functions one at a time with a standard signal analyzer. We have
also just received two Siglab units for doing multiple TFs (thanks Dennis)
and will get those fired up asap.
From: Riccardo DeSalvo <desalvo@ligo.caltech.edu>
We welcome Kentaro, Brett, Tastu, Lisa that just joined SAS
And welcome back Kenji and Virginio
Last week we declared public vacation for Kipfest, not much done
except
unpacking and the preparations for this week’s measurement.
Akiteru, Hareem,
Test of horizontal accelerometer on IP with closed loop on LVDTs, test
ongoing with open and closed loop and different gains.
Soy, Hareem
Measuring thermal properties of GASF, done two measurements at minimum
and above, one below to be done, will measure the variation of Dh/DT
to
find a zero in h.
Szabi oil bearing hardware advancements.
Flavio Chenyang, Soy
Collecting components for further Marconi tests.
Virginio
Elba proceedings. Statement, will need urgently more fft capability,
8K$/4 channels.
Yesterday started the different measurements, all very preliminary after
only 1/2 day measurements each.
Tatsu, Kentaro
Measuring F0 resonances hanging from a side, found 30 Hz peak on the
side surfaces and not on the top one. First other peak at 200
Hz on top
surface.
Kenji same measurement on standard filter hanging from center.
Found 30
Hz resonance on top surface and not on sides.!!!
Szabi measured a single IP leg, made frequency vs. load curve down to
25
mHz at 66 Kg load.
Achieved balancing by shifting load on 1 leg? Is it viable on
three
legs? Can eliminate/reduce tuning springs?
Internal modes >= 30 Hz
Are we picking 30 Hz from environment? Few month ago same problem
at
15Hz, exactly half???
Lisa
Cabling creepy house.
Hareem Szabi
Upgraded DAQ C++ programm, betterflexibility.
Brett
Starting stepping motor controls from DSP.
Gianni, Riccardo
Designed suspension blades for Penn State Un.
Alessandro, Francesconi
Making printed circuits for horizontal accelerometer.
Testing differential pickup for horizontal accelerometer
Alessandro, Gianni, Riccardo
Starting vertical accelerometer design.
G&M
Final prototype Horizontal accelerometer in machining.
LSC SWG Monthly Meeting minutes
From: David Shoemaker <dhs@ligo.mit.edu>
Notes from SWG telecon, 7 June 00, 8.30 pacific, one hour
ACTIONS follow ***; please look for your name! to be reported on next month, but you are invited to deal with them expeditiously.
Comments welcome.
Agenda:
1) Lab/Organizational issues
announcement of selection; pointers to documents:
The seismic isolation Technical Advisory Group (TAG) report is at
http://www.ligo.caltech.edu/~sanders/M000154-A.pdf
and the draft decision by the LIGO Laboratory Directorate on the selection of the technical approach is at
http://www.ligo.caltech.edu/~sanders/M000170-00.PDF
2) Suspensions
a) suspensions per se
- just one baseline can be worked for now
(value in parameterization, to be developed as possible)
- needs input on the mass for the design
- sapphire: unambiguously our baseline substrate material
- dimensions: COC also working the issue
*** Peter Fritschel action to recommend test mass dimensions
Eric: materials properties hard to measure
and a range of values found in the field
will probably have to proceed with present knowledge
b) fibers fabrication
Phil: making better ribbons than a week ago
concern: similarity of fraction of a mm length identicalness required
*** GEO action to work up a real requirement for similarity of length
*** Phil action to research C02 welding
are there significant advantages?
what is the installation required? should we try it; at GEO
or CIT?
c) fibers noise performance
Peter S: good progress on violin string excitation monitor
Harry: control electronics - might the LIGO I digital controller be
good
for suspension prototyping at GEO?
*** dhs action: digital controller document to Harry
3) Test mass materials and integration
a) coating losses
Peter: problem with REO not wanting to make time for us
MLD: trial run with alternative coater
*** jordan action: status of sapphire test piece
b) bulk losses: sapphire, fused silica
Peter: 55e6 in fused silica, 3 mm thick
suprasil W, _really_ hot flame polished
could we do this to ribbons? asks Phil
*** Garilynn action: should pursue this with W, SV -
samples to Peter Saulson
Sheila: pieces with flat under studay
Phil: large sapphire 6kg best 1.8e8
c) bonding, welding
hough: ear came off after a year, with poor bonding
silica to silica, but corning 7940, not superpolished
ear maybe not cleaned
environment: stored humid, then mostly air in lab; no load
4) Thermal noise measurement
a) TNI near-term
mode cleaner locked in air perp polarization
photothermal
*** dhs action: braginsky paper to all in SWG
b) plans long-term
5) Isolation systems
a) stiff system
planning for next phase
b) soft system
TAMA parts arriving, tests starting
c) evaluation status
see pointer above
6) LASTI
discussion of parameter: how much testing on campus,
how much testing in first installation
how long to we work on the first one
important to think carefully about risk
what is the risk we can support at time of first installation
what can we do besides the direct test which will improve confidence
question is suspension/test mass
(isolation testable to specs; all controls testable;
??? thermal management completely tested first ???
what lies in the last factor of thirty in sensitivity
*** mez/dhs action: LASTI: analysis of 'sweet spot' of what we can accomplish (dhs/mez)
=============================================================
GEO/Norna Robertson:
Here is a brief report on work in GEO towards LIGO II in the past month.
1) Design of new pulling machines for fibres and ribbons completed
and
construction begun
(Geppo Cagnoli and Stephen McIntosh)
2) Further work on thermoelastic damping in fibres as a result of change
in
Young's modulus with temp. has been carried out by Geppo Cagnoli in
collaboration with Phil Willems. This results in noise which is stress
dependent, and the implications of this will be fully investigated
over the
next month.
3) Measurement of a sample of GGG in collaboration with Stanford is
yielding a Q value of approx. 2 x 10^7. This is thought to be limited
by
surface quality (Sheila Rowan and Peter Sneddon)
Plans for next month.
1) Continuation of thermoelastic calculations
2) New evaluation of losses associated with silicate bonding will be
carried out on a small Corning 7940 mass with silicate bonded ears
suspended by silica fibres.
3) Implementation of new fibre and ribbon pulling machines in Glasgow
and
fibre pulling machine in Hannover.
4) Work will start on writing design review requirement document for
suspensions, following clarification of what is required.
Stanford/Sheila Rowan:
Interim report on LIGO II related work.
Further Q measurements ( in collab. with Glasgow) have been made
of the sapphire sample which has a flat polished on it in preparation for
bonding. The Q has now increased from 1.4 x 108 to 2.2 x 108 - getting
closer to the 2.7 x108 pre-polishing number. It becomes increasingly difficult
to improve on the measurements, - we will thus settle for this number and
now bond to the mass.
From the set of silica/silica bonds made at Stanford with Phil Willems
and colleagues at Caltech, ‘frosting’ in the form of crystals shows up
in many of the bonds. We are investigating possible reasons for this.
At Stanford a subset of bonds has been made to investigate the possibility
that the frosting is related to residue from the detergent used in the
cleaning process.
A set of polished fused silica rods has been purchased, which will be
silicate bonded at Stanford as part of a collaborative experiment with
Syracuse to further investigate the mechanical losses in silicate bonds
We have bought and started to set up the ‘Algor’ finite element analysis
program to model the mode frequencies and shapes of both isotropic and
anisotropic materials with particular application to studying the
losses associated with coating of sapphire samples. This is done collaboratively
with the Glasgow group.
Plans for the coming month:
Bond a set of polished fused silica rods for experiment with Syracuse
Bond a fused silica ear to a thin fused silica plate in order to make
a low mechanical loss suspension for use in the coating experiment at Syracuse
Bond a fused silica attachment to the sapphire mass described above,
for mechanical loss studies
Visit Phil W. and colleagues in Caltech to assess plans for further
bonding studies silica/silica and silica/sapphire
Continue with the Q measurements of the single crystal silicon samples
we have.
===========================================
Caltech/Phil Willems:
Fiber/ribbon work:
We have begun pulling ribbons in our automated lathe and have a few
promising
samples, but ran out of raw stock and received more only yesterday.
Work is
continuing. Strength of ribbons so far is much lower than for fibers
of similar
cross sectional area. Also, ribbons are bowing under gravity in the
lathe,
unlike fibers. Pulling faster may solve this problem but we are also
looking
into mounting our lathe vertically.
We are also assembling a fiber/ribbon violin Q experiment to verify
the quality
of our lathe-drawn suspensions. It is expected to be ready in a month.
Silicate bonding work:
We have made another set of ten bonds at Caltech identical to those
made at
Stanford to see if the technique is transferable. One has been tested
to over
2e7 Pa of shear breaking strength. We test the others in a few weeks.
Meanwhile, we have analyzed the 'frosting' that appears in bonds and
believe it
to be of two types: large white crystals of potassium hydroxide, indicating
no
bonding, and a much fainter diffuse cloudiness due to etching, indicating
bonding. The crystals test positive for potassium at JPL. We have new
fused
silica substrates arriving in July, that we will use for new tests,
including a
test of how bonds cure under an applied load, which should tell us
if we can
skip the 50-day cure period before hanging the optics.
============================================
Syracuse University/Peter Saulson:
SWG Progress Report 6/1/2000
Test Mass Materials Development
Syracuse activity: Anelastic aftereffect measurments
Personnel: Scott Kittelberger, grad student, full time
Steve Penn, postdoc, roughly half time
Recent progress: Fitting code is being overhauled.
Mostly done, but still working on details of removing
sinusoidal signals from rigid body modes. This is
important now that sample is suspended from wire slings.
Scott Kittelberger is starting up the learning curve
with ALGOR FEA package, trying simple modal analysis and
also stress analysis problems.
Next month's plan:
Finish fitting routine, and evaluate
status of measurement with wire-sling-supported samples.
Milestones: On track to have useful things to say
about both fused silica and sapphire by 4Q01.
Test Mass Mechanical Integration
Syracuse activity: Coating loss experiment
Personnel: Gregg Harry, postdoc, full time
Recent progress:
Gregg has arranged to have our 1.9 cm thick fused silica
sample coated in the next REO coating run arranged by
Peter Fritschel. REO only just realized that they would
have to retool to fit this piece in, and have deferred
the coating run a couple of weeks past the previously
set June 4 date.
Gregg and Sheila Rowan have arranged to have Sheila
bond an "ear" onto one of our 2.5 mm thick fused silica
samples.
Next month's plan:
Get 1.9 cm sample coated. Attach ear
to 2.5 mm sample.
Milestones: On track to meet milestone "4Q00: Impact
of coating assessed."
Suspension Fiber Development
Syracuse activity: Study of Q of fused silica fibers/rods
Personnel: several undergrads, plus small amounts of the
time of Penn, Harry, and Gretarsson
Recent Progress:
The 3 mm fused silica rod was aggressively flame polished.
Quality factors measured afterwards showed record high values,
with modes at 726 Hz and 1567 Hz giving Q's of 50 million.
This is better than the best previous room temperature values
(30 million) measured by anyone. Surface losses were evidently
limiting our previous measurements, and it is unclear whether
surface losses are still limiting these measurements.
Next month's plan:
Rehang 3 mm sample with extra "bob" in
suspension, to check for any remaining recoil damping. Perhaps
flame polish again, if necessary. Install new oven to measure
Q as a function of temperature.
Milestones: On track to meet "4Q00 silica ribbons/fiber
research completed."
Excess Noise Studies
Syracuse activity: Development of violin mode sensor
Personnel: Andri Gretarsson, grad student, full time
Recent progress:
New fixtures completed, single wire pendulum hung and
damped in all degrees of freedom, inside a closed box
(in air). Violin modes strongly visible with shadow sensor,
using very small (of order 10 micron) spot.
Alignment is, not surprisingly, pretty fussy. Violin modes
show seismic excitation.
Next months's plan:
Calibrate sensor. Evaluate optimum spot size. Design
seismic isolation.
Milestones: On track to meet "4Q01: Characterization
of fiber excitation."
=====================================
Penn State/Gabriela Gonzalez:
Suspensions and Seismic Isolation Working Group Status Report,
Month of May 2000
Mark Beilby attended April APS meeting April 29-May 2 and gave a
contributed talk on the work being carried out at Penn State.
Preparation is progress for tests of modal damping vs. point-to-point
damping and measurements of sensor/actuator and mechanical cross coupling
in the double pendulum. Initial tests will be done on a single pendulum
supported by cantilever springs and controllable in all six degrees
of
freedom.
In preparation for these tests the following has been done in May and
continuing in June:
Improvements are being made to our data acquisition system.
A single pendulum hung from cantilever springs is completed and can
be
controlled in all six degrees of freedom with OESM's and controllers
from
the MIT PNI. Currently all six degrees of freedom can not be controlled
simultaneously, as we do not have enough OESMs connectors, but a source
has been found and they are on order. In the April a program to calibrate
the position sensors of the OESM's and the coil/magnet strength coupling
was completed.
The resonant frequencies of each of the six degrees of freedom of the
hanging single pendulum have been measured and compared with our model.
The first tests will be done in air (eventually in vacuum). A plexi-glass
enclosure has been constructed as an air shield.
The tuning of the OESM controllers is now in progress.
A robust method has been developed to fine tune our vibration shakers,
so
they will shake along only one axis. Refinements to the tuning method
and
to the mechanics of the shaker are continuing. Initial tests will be
done
with a vertical only motion shaker. For this vertical motion only
shaker, when it is driven, the horizontal motion has been reduced to
1 to
2 percent of the vertical motion, which is near the measurement limit
of
our accelerometers.
Work is just beginning in modeling the crossing-couplings in our pendulum.
The electronics shop of the Physics Dept. of Penn State has begun building
electronics for the point-to-point damping test.
A program for the development and construction of new OESM's has begun.
A
series of LED's and several split photodiodes have been obtained. Mounts
for the LEDs and photodiodes are being constructed and a simple
differential amplifier has been designed and a prototype has been built.
Tests using various LEDs will begin shortly.
Measurements of environmental seismic noise in our lab have begun using
our Guralp seismometer.
TNI/Eric Black
This month we assembled and locked the TNI's mode cleaner in a variety
of
configurations. We have both locked the laser to the mode cleaner,
with
the earthquake stops holding the mirrors in place, and the mode cleaner
to
the laser, with the mirrors freely suspended and a length control signal
applied to one mirror.
With the laser locked to the cavity, we were able to measure the finesse
of
the mode cleaner with s-polarized light by measuring the cavity pole.
We
obtained a value of 5260+/-500 under vacuum, entirely consistent with
our
expected value of 5000. For locking the cavity to the laser in air,
we
rotated the polarization 90° to reduce the finesse and make lock
acquisition easy. (Many thanks to Bill Kells for teaching us this trick!)
Acquisition was prompt, and the lock was very robust.
==========================================
Caltech/Riccardo Desalvo:
Last month we continued tests on existing LIGO SAS hardware and we have
got
the first TAMA tower built, it was delivered today, we also made tests
on the
horizontal accelerometers and started production of a second accelerometer
prototype. We have validated several points in stability, creep, creak
and
hysteresis. We have proven to ourselves that bolted clamp of blades
are
intrinsically worse that wedge clamps.
Controls of the LIGO tower are doing OK. We are expecting to remove
to the
new location, always inside the Synchrotron later in the month.
In the new location we will assemble a full chain and shake the base
of the
IP with swept sines and simulated earthquakes.
We received the first TAMA prototype, we are assemblying it. This month
we
are testing and validating the TAMA SAS prototype to start the production
of
the real towers in the second half of June in order to take delivery
before
August and install in Early Autumn.
Also we expect to get delivery of the second horizontal accelerometer
within
two or three weeks and start series production for delivery also by
August.
In July we should be running its controls.
We made some tests on tiny MGASFs, with a prototype with 2.5 Kg load.
They
will be useful to suspend masses in the TAMA mirror suspensions and
to build
a vertical accelerometer.
Designed blades for mirror suspensions for Penn State University. If
required we can build them within a couple of weeks.
Akiteru has almost finished the conceptual design of the TAMA mirror
control
and suspensions. The design should be finalised next week and the
engineerization done within a month. First prototype by August to be
matched
to one of the towers.
We will be starting assemblying the second generation creep measurements
in
the Totem aiming to first results by end of the summer. Measurements
of
creep and creak through acoustic emissions are in program as well.
==================================================================
JILA/Tuck Stebbins:
May Progress Report: During the past month, we have worked on constructing
a
test rig to evaluate cross-coupling in the electromagnetic forcers
used in
the two stage active isolation system. In the process of fabricating
the
test rig, we developed and tested a new design for a non-contacting
imaging
position sensor which would meet the design requirements of an active
LIGO
II isolation system. The test rig is nearly complete. We have also
supported the control system work at MIT on the two stage active prototype
that we delivered in March.
June Plan: In the next month, we anticipate finishing the fabrication
of the
forcer test rig and the evaluation of the forcers. We will continue
to
support control system development on the prototype at MIT. We expect
to
begin project planning and early design work on the next generation
of
prototypes.
============================================================
Stanford/Brian Lantz:
Isolation work at Stanford:
The interactions of the GEO triple pendulums and the active platform
have
been measured, and the measurements show that, from a pendulum control
perspective, the active platform is practically indistinguishable from
a
very stiff table (except that it is much quieter). A short description
of
the measurements will be available at the stiff team web page by the
end of
the week.
We have begun noise measurements of the hydraulic actuator. They are
extremely encouraging, but a variety of things must be done before
we start
showing the data around.
Hua has finished the first draft of the sensitivity analysis of the
stiff
reference design. Its performance is very robust to reasonable parameter
fluctuations, as measured with both Mu-analysis and Monte-Carlo techniques.
A first draft of the results will soon be available at the stiff team
web
site.
==============================================================
LSU/Joe Giaime:
SWG Update for LSU group:
Seismically-isolated granite table support for creak test facility
has been installed at LLO Y-end lab, and is under test. (Michelle Kingham,
Dan Busby, Joe Giaime). Data acquisition system on order. Vacuum system
to be borrowed from Stanford (thanks!) Lab space and lots of help from
LLO staff (thanks!)
Huddle test of LLO seismometers conducted and data analyzed, indicating
large variation in high-frequency instrument noise among the three; more
analysis to come. (Warren Johnson.)
Coordination of "stiff" LIGO-II SEI planning. (Joe Giaime)
====================================================================
MIT/Sam Richman:
Stiff double active stage prototype activity at MIT update for SWG telecon
1 June 00
(S. Richman, J. Rollins, S. Chatterji)
In the past month, we have closed all 12 loops on the stiff two-stage
prototype, using geophones and relative position sensors. This allowed
for the first time a measurement of top-to-bottom horizontal isolation
from ground noise. There is a small band of coherence around 8 Hz between
ground and lower stage motion, and at 10 Hz the isolation is 45 dB. Below
8 Hz the motion is dominated by relative position sensor noise. The vertical
isolation at 10 Hz is 63 dB. The stability appears quite good, and the
forcers use only about 5% of their dynamic range.
We took advantage of our severe environment to do a robustness/stability
check. One night the high bay air conditioning died and the next morning
the temperature was about 24.5 deg. C. We closed loops and let the system
run throughout the day. The A/C was repaired in the afternoon, and the
temperature came down slowly. We opened the loops at the end of the day,
after 8 hours of operation with a ~3 deg. C temperature drift and the dull
roar of construction next door.
Jamie is using the digital control system to measure simultaneously
multiple transfer functions of the prototype. We plan to be using this
information soon to refine SISO controller design, integrate the broadband
seismometers, and add cross-terms to optimize the system performance. Shourov
is nearly finished building a set of current drivers for the voice coil
actuators, to replace those we borrowed from JILA.
============================================
MIT/Mike Zucker:
LASTI:
Vacuum/Infrastructure:
Continuing characterization of outgassing loads and system performance.
Operating pressure is now below 1e-6 torr, dominated by water vapor.
Water flux after 1500 hours under vacuum corresponds to a surface rate
of approximately 5e-11 torr-liter/s/cm^2 (high by LHO/LLO standards
but adequate). Hydrogen rate is about 1.5e-11 torr-liter/s/cm^2. We
found evidence of a substantial air leak (about 1e-5 torr-liter/s)
which we believe we've isolated
to a particular fitting we added before the pumpdown. We will need
to
fix this before proceeding with annulus tests.
Interferometer design:
The LIGO II planning meeting at MIT in May evoked some strategic rethinking
of the LASTI mission. Reassessing the technical risks as we now
percieve them, considering the serious limitations due to small beam
size in campus machines, and taking into account revisions to the
proposed LIGO II upgrade strategy, we all felt the previous plan to
build a high displacement-sensitivity interferometer may have missed
the
point. We're now considering a relatively modest
displacement-sensitivity test of the new SEI and SUS subystems in
combination with a LIGO II PSL/mode cleaner functional test and
characterization. The high-sensitivity displacement test would be deferred
to the first LIGO II interferometer components to be installed. We
plan to
flesh out these ideas for discussion with our Advisory Panel in the
near future.
For additional information about this report, contact sanders@ligo.caltech.edu