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The LIGO Executive Committee Agenda for Monday June 23, 2003 will be:
(Meeting time: 10:30 am Pacific Time)
Open meeting 10:30 - 11:30
CR-030011 Seismic External Pre-Isolation at LIGO Livingston Observatory D. Coyne May 16, 2003
CR-030013 Atomic Clock Timing Systems D. Coyne
June 9, 2003
Special Items: NSF review reprise, NSF review of subcontracts
no report
LIGO Weekly Site Telecon (Lindquist)
There was no site teleconference held on Thursday, June 19, 2003 due to the teleconference with the NSF PAT team.
The list of current actions revised to reflect
the status of open actions assigned through May 29, 2003 may be found at
ACTION
LIST.
From: Ed Chargois <chargois_e@ligo.caltech.edu>
>From: Linda Turner - turner@ligo.caltech.edu>
Web pages for the DCC give simple how-to's for document numbering, easy access to the latest on-line documents, and search capabilities for the DCC database. Take a look. . .
ACCOMPLISHMENTS
ACTIVITY
From: Esther Cunningham <esther@ligo.caltech.edu>
Press here for ACCOUNTS PAYABLE HISTORY DATA .
From: "Brambila, Ruth" <Ruth.Brambila@caltech.edu>
From: irena@ligo.caltech.edu (Irena Petrac)
SUPPORT (Baldon, Lloyd, Tischler)
>Irene Baldon
For list of documents that are being used to develop Adv. LIGO Cost and Schedule, see http://www.ligo.caltech.edu/~tfrey/Cost_MTG_082002/
Advanced LIGO MRE Proposal (Highest Priority)
Project Web Site for posting schedule and progress related data continues to be updated with the latest and greatest.
The Construction project quarterly report for the end of February is overdue. Dave Beckett is now working on this.
Things we are going to need to do over the next month include the work
plan for FY 2004 Operations, the Final Report for the Construction Project.
The following change requests are pending or new. Dennis Coyne submitted CR-030013 for Atomic Clock Timing Systems. I will request that these change requests be placed on the agenda for the next meeting of the Executuve Committee.
| CR-030008 | Furniture for the auditorium lobby, interaction area underneath the skylight atrium in the OSB, and on the second floor interaction area of the new laboratory/office building. (ON HOLD pending additional cost data.) | M. Coles | April 29, 2003 |
| CR-030011 | Seismic External Pre-Isolation at LIGO Livingston Observatory | D. Coyne | May 16, 2003 |
| CR-030013 | Atomic Clock Timing Systems | D. Coyne | June 9, 2003 |
The minutes for the Change Control Board that met on June 2, 2003 as part of the normally scheduled Executive Committee Meeting have been prepared. A .pdf version of the minutes will be found at: http://www.ligo.caltech.edu/~phil/ChangeBoard/M030122-00.pdf
Change Request CR-030012--RFI Mitigation, was approved (at least to begin the FY 2003 effort).
Signed originals of the documents will be found in the document control
center.
From: Cindy Akutagawa <cindy@ligo.caltech.edu>
Summary of Commissioning Activities at LIGO Hanford Observatory (compiled by M. Landry)
2K IFO
The 2k MMT1 was repaired Thursday (Bland, Gray, Cook). HAM7 was vented and it was observed that no magnets were stripped from the optic, the earthquake stops having provided support. After confirming that magnet-bonds passed a strength test, the optic was rehung in situ. A new MMT1 baffle was added, as well as baffles on cable connectors. Additional details can be found in Betsy's elog . The 2k MC was relocked and the beam spot was observed on the MMT2 baffle, so that post-vent alignments look reasonable.
GHS NOTE: VERY IMPRESSIVE RECOVERY!
Analysis by Mike Smith showed how an RM misaligment landed a beam on the MMT1 wire. 4k RM alignments and extents were revisited to ensure safe operation.
In order to obtain high resolution spectra of mechanical resonances such as pendulae, bounce modes and violins (Berkowitz), all 2k and 4k optics were left undamped for five hours on Friday evening.
A power budget was worked out for the PSL (Garafoli, Savage). Of the 6.6W emitted by the laser, 4.25W arrive at the MC, losing 1W in the PMC and 1.35Win the IOO train.
4K IFO
The BSC1 coarse actuation system was employed to return the errant SPOB beam back onto ISCT4. The successful move dropped the beam a full cm on the output table, and the output spot looks good and round. Several consecutive elogs report on SPOB.
Gatevalves were briefly opened Thursday night, and the 4k was locked and put into common mode.
-------------------------------------------------------------------------
New laboratory building (J. Kern reporting):
-------------------------------------------------------------------------
Cabinetry for the new laboratory has been delivered and we're working
with the installer to make sure water, air, power and comm. lines are
correctly located. Building security system for the new building is
now
installed and we're doing a final logic check on the access controls.
Plan is to enable the system next week.
Lightning protection and grounding (MZ for R. Wooley and K. Watts):
-------------------------------------------------------------------------
Contractor has nearly completed the circuit for the new ground bus
around the LVEA, temporarily held off by rain from the last 30 feet
of
trenching. As this is completed we are making our final decision on
where to position the new technical ground grid.
Civil & vacuum facilities (MZ for A. Sibley):
-------------------------------------------------------------------------
Steelwork is up on the new storage building. Contractors appear on
or
near schedule despite rain. Front walkway is usable on one side and
making progress. Guard shack is up on new front gate.
The previously planned LVEA power shutdown for load center maintenance
and air plumbing rework has been deferred; thermography indicated load
centers are not in imminent danger. The air line work will now be
accomplished by doing a quick dropout to install an isolation valve,
enabling backup air from the vacuum equipment skid to temporarily stand
in while the main air supply is reworked.
General computing (S. Roddy)
-------------------------------------------------------------------------
The vast majority of this week has been spent trying to fix a major
problem with my main fileserver here at LLO. Sun has basically been
stumped over this one. All of the fixes they have suggested have not
worked. I have the command line portion fixed after Keith Bayer found
a
newgroup posting related to a portion of the problem that I was having.
The fix involved getting a specific patch from Sun.
The usual work related to SURF students arriving has been going on since
I returned from the conference. Computer requests, account requests,
general computer usage questions, policy agreements, etc.
Setting up a new computer for Rusyl. When I am finished his old computer
will be turned into a SURF workstation.
CDS Software (Ash Khan)
-------------------------------------------------------------------------
1) Prepared scripts that automatically do the preparation for locking,
Xarm, Yarm, Mich, PRC and Full.
2) Implementing and testing the Watchdog control for the digital suspension.
LDAS (Igor Yakushin)
-------------------------------------------------------------------------
LDAS admin:
1) 3 T3 disks failed during recent week. Two in the unused T3 and one
in
the metaserver's T3. Replaced the one in the metaserver's T3 with the
new disk. Ordered two more replacement disks.
2) Finished copying LHO's AS_Q only RDS to LLO.
3) The 4th tape drive was installed into L700.
4) Replication: experimenting with ASNLOAD in an attempt not to deal
with millions of spill files during the initial replication cycle.
5) Copied LLO_S2 and LHO_S2 to MIT's metaserver.
6) With Phil's help trying to figure out why some jobs periodically
fail
at LLO with the connection time out between nodes and datacon. It looks
like the jobs were failing only on node40 and node11. Removed them
from
the list of active nodes.
LDAS data analysis:
Running waveburst on S2 data for H1 and H2.
LDAS power and A/C (Igor, Allen and Rus)
-------------------------------------------------------------------------
Preparing to briefly shut down the new building to allow cutin of new
power panels for increased LDAS load. Personnel in the new building
will
be given notice and instructions for powering down personal workstations
and arranging to work elsewhere during this time. Interferometer systems
and the LVEA and OSB will be unaffected.
Interferometer commissioning:
-------------------------------------------------------------------------
Protracted difficulty in locking the interferometer last week was traced
to a blown common-mode control board, and the date and probable cause
of
the failure pinpointed.
After correcting this fault the machine was aligned and locked up, to
our great relief. Alas full-up common mode control was not attained.
The
reluctance to maintain lock as the CM control was sequenced is under
investigation and not yet understood. As a result a noise baseline
is
not available; other proposed changes
and system upgrades, including steps to increase the power and improve
the MC servo for better frequency control bandwidth, are on hold until
this baseline is reestablished.
The PSL master oscillator NPRO laser was swapped out due to suspicious
behavior of the existing unit; unfortunately the replacement appears
to
be showing signs of impending failure, with its power declining
alarmingly in the first few days of operation. We're holding off a
second swap until diagnostics on the NPRO diode temperature and
operating current are completed and to keep going on
other investigations.
A decision memo (M030123-00) was issued by Barry Barish and Gary Sanders selecting the Hydraulic actuator version of the External Pre-Isolator (EPI).
Jonathan Kern
Sample bellows testing continues. Several samples
of the 17-7 alloy
have been pressurized to 500 psi without yielding.
Ordered a higher
pressure regulator (test regulator maxes at 500psi)
and test will
continue to determine yield, and ultimate pressure
of 3 samples. 3
samples of the 304 alloy bellows have been tested
and are found to yield
150>180psi.
Final bids for manufactured and purchased components
of the HEPI system
have been received and a procurement plan has been
prepared and offered
to Dennis.
Dennis Coyne
A procurement plan has been presented to LIGO contracts and discussed briefly with the NSF. Contracts exceeding $100K require NSF approval. The plan is being reviewed. We will start procurements on the commercial catalog items. Build-to-print efforts will be started when signed DCNs are in place and the principals have all had a chance to see/approve any (slight be definition) changes from the LASTI prototypes.
Sander Liu
Designed a PCB for concept proofing the L4C pre-amplifier
design. Paul Russell will help mill out the prototype in the shop in the
next few days.
[D. Coyne note: circuit schematic and design description will be sent to the EPI group for review soon.]
I completed the installation, testing and debugging
of the new version
(rev_2.6) of the DMT software at LHO. This required
the installation of
gcc-3.3 and of various other GNU development tools.
Since returning from
Hanford I have continued the data quality studies,
especially looking
into saturation of photodiode amplifiers and ADCs.
1. ISS board is being stuffed and testing will
commence as soon as stuffing is complete.
2. Working with Larry Jones on the re-design
of the magnetic actuators from a thermal standpoint
3. Schematics for RFPD are complete, will be
sending them out this week for last minute review
4. Preparing the details for an interface board
to connect the rack mounted EPI interface chassis to the Pentek and ICS1110b
for Rolf and company
5. Working with Eric Black and company to enable
them to process their own printed circuit boards. This involves a
bit of CAD teaching for Eric's staff
Last week a little circuit comprising of a voltage
reference and a
2-pole low-pass Sallen-Key filter was fabricated.
The performance of the
circuit was less than expected. After checking
the noise measurements, it
dawned on me that I had neglected to include the input
current noise in my
circuit model. After replacing the LT1028AC
with an OP-07, the noise
performance of the circuit improved to be approximately
25 nV/Sqrt[Hz] at
10 Hz. This is still a few nanovolts above the
PSpice noise prediction but
part of that might be due to the implementation of the circuit.
A ray height analysis defined the danger associated
with the RM retro beam being deflected. If the deflection is limited only
by the earthquake stops of the RM. The retro beam leaving MMT2 will spray
focussed errant beams throughout the entire HAM7 (or HAM1) chamber within
the opening of the MC beam tube. The only mirrors that don't get hit are
SM1 and SM2.
If the 2K IFO RM tilt angle is steered to the limit of 0.5 mrad by
the controller, the retro beam angle from the RM will be 1 mrad, which
will result in a cone of steered beams of 150mm radius around the MMT1-this
will hit the wires on MMT3. In the 4K IFO, steering the RM by 0.5 mrad
will result in a cone of steered beams of 95 mm radius around the MMT1-this
may also hit the wires on MMT3. In conclusion, I think it is risky to steer
the RM until baffles are placed in front of MMT1 and MMT3.
The errant beam baffles for HAM1 and HAM7, for the LHO and LLO interferometers, are in process of being completed. Daniel will define the location of the RM beam dump that has been moved to the MMT1 baffle. K. Mailand is finalizing the baffle drawings and chamber locations. Material has been ordered and additional RM beam dumps are being fabricated.
A BRDF meter is being built, based on the design of Rai Weiss, for general use in measuring the BRDF of baffles and auxiliary mirrors. Parts have been
We are taking more TRANSMISSION measurements for the
NEW 5.90 inches in diameter ~ 3 inches thick Sapphire mirror. We will be
measuring the scattering of the this mirror. We have made a new base
holder specifically for this mirror to accommodate into the scatterometer
system. Right now, I am making a modification for the mirror holder
to catch the transmitted beam. Also, we are measuring the birefringe
of this mirror and find out the changes in the index of refraction.
So far we are taking measurements at 0, 45 and 90
degrees mirror position.
Absorption Test Measurement prototype in progress
OTF Lab. (W. Bridge)
Contamination Cavity # 1
Test sample a 10mm Capacitance position sensor (given By: Rich
Abbott)
The chamber is pumping down and cavity is locked and we are taking
ring down and beat frequency every day.
As specified before, this simple is clean! we did not noticed
mirror contamination nor absorption.
Please see Dr. Zhang graphs for absorption, ring down and thermal lensing.
OTF Lab at Lauritsen ROOM 38
Cavity #3
This cavity has 70 ppm mirrors and hung with one end at 1.8 degree
higher that the other end.
Cavity is locked and we have 147 mw of power with a 95% ! visibility.
We are taking ring down and beat frequency every day. Unfortunately,
this cavity ring down is increasing instead of decreasing as time goes
by.
We blame on the mirrors since these were mirrors washed and cleaned
as specified but we can notice the
absoption have increased by the Beat frequency change. We will
continue taking measurements everyday
and if ring down continues decreasing, we'll change the mirrors.
We are waiting for the new mirrors
that Helena have ordered.
Cavity #2 Test cavity STILL in STANDBY.
Optical train upgrading is in progress.
New cavity assembly is in progress for this chamber.
PSL Lab.
I have finished the assembling of the new 2 inches high vacuum mirror
mount wanted by Mike Smith,
Later the rest of the mirrors will be assembled as time is permitted.
Having last month identified laser frequency noise and electronic noise as our limiting noise sources above 1 kHz, we have spent the last few weeks trying to suppress them. To bring the laser frequency noise down, we installed a broadband Pockels cell for fast frequency correction and started work on a fast-path servo. Four separate phase-loss mechanisms above 100 kHz made debugging this loop a little problematic, but once we identified each one quantitatively we were able to remove them and, where necessary, design new electronics to replace old ones that offended at high frequency. We have four new boards to make to improve our noise floor: a Pockels-cell driver for the fast loop, a new boost stage for the mode cleaner, and two new servo filters for the North and South Arm Cavities. The design for the boost stage is complete, including the board layout, and as soon as we generate the Gerber file we will send it off to the board house for fabrication. The schematic design for the Pockels-cell driver is done, and we are working on board layout. Design for the new arm-cavity servos is in progress, with the schematic-level part almost complete.
Work continues on quantifying and reducing noise between 100 Hz and 1 kHz. We have several promising leads, mostly involving scattered light, but we won't know if our models are correct until we can actually reduce the noise.
see Advanced R&D report
no report
From: Richard Mittleman <richard@ligo.mit.edu>
MEPI
Over the weekend we ran the MEPI in its full modal configuration, with
all
7 loops and the optimized sensor correction coeffiecents. Some
results
can be found on the LASTI ilog for June 16.
We have also spent some time finishing up the Witness (a Streckhiesen
mounted on the support table) transfer functions.
We finished up a sensor correction model which uses measured
open loop
transfer functions to predict the system preformance using the blended
sensors.
From: Janeen Romie <romie_j@ligo.caltech.edu>
AdLIGO
Worked on updating the Hybrid OSEM assembly
and testing specifications.
Participated in the NSF Review.
From: ctorrie <ctorrie@ligo.caltech.edu>
Mode Cleaner Suspension
Damping
Mark Barton, Ken Strain and I have now successfully damped all of the
modes of the triple pendulum that are supposed to be damped. All have a
settling time of less than 10 seconds. Transfer functions will now be carried
out and compared with those measured in
2nd Suspension
A second mode cleaner suspension is in the process of being assembled. It is hoped that it can be fully assembled including the hybrid OSEMS in the next week or so. Janeen Romie has been working with Dave Robertson and Jay Heefner regarding the electronics for this suspension.
ETM Layout
MPL and I will consider looking at what adjustment can be applied to
the structure rather that the suspension. This will allow any adjusters
to be easily removed therefore reducing
the overall mass.
Betsy Bland and Doug cook have offered to explain and describe adjusters
used and lessons learned from these during
the LIGO I installation.
From: Jay Heefner <jay@ligo.caltech.edu>
Adv LIGO SUS
========================
- System level wiring diagrams and designs have been started for the
LASTI suspension system to be installed this fall. The design
will accomodate the mode cleaner and recycling mirror prototypes.
2.
Discussions and detailed interpretation of 4k H1 scatterometerFrom: Helena Armandula <ahelena@ligo.caltech.edu>
Advanced LIGO Optical Coatings
A teleconference took place last Monday 16th to respond to questions
that the possible coating manufacturers, REO, MLD, ATF, SMA and CSIRO,
had concerning contractual and technical issues.
Basic questions were answered during the call;
the most specific ones, dealing with specifications, will be answered
by E-mail this coming Friday.
PHOTON DRIVE R&D
A SURF student, Tom Essinger-Hileman, has begun working on the photon
drive experiment at the 40m IFO at CIT. A second SURF student, Aidan Crook,
will arrive the week of 6/23 to begin work on modeling the advanced LIGO
photon drive system.
Sent
"Letter of Interest" to 5 coating manufacturers.
The five responded indicating their
interest
in the project. They are: REO, MLD, SMA, ATF and CSIRO.
An
RFP was sent to all of them and a teleconference was scheduled for Monday
16th to
respond
to questions they may had concerning contractual or technical issues.
Basic
questions were answered during the call; the most specific ones, dealing
with
specifications,
will be answered by mail this coming Friday.
So,
it is exciting to report that once again we may have a coating development
program
ongoing
soon.
Garilynn:
Sapphire Status
Phil
is finished with the Q measurements of the pink piece of large sapphire,
there is no
change
in his analysis. There is a competing theory that might fit the data. This
theory
does
not rely on a bad barrel polish. Phil is asking when we can have these
pieces
repolished
as he would like to compare the results. Insaco is still working on the
barrel
polish
technique for large pieces, CSI is aware that we are ready to have another
go at the
edge
polish and is working on that schedule.
I
spoke with Chandra again about collaboration on annealing for the purpose
of reducing
absorption.
He will call Roger for the details of the process that has been used and advise
us
if he has any furnaces which might be useable.
We
have received the 125 mm x 50 mm piece of Heraeus 311SV which is on loan
to us
from
the 40m TM spares pool. This piece is slated for Q measurement by Kenji,
he may
not
be able to get to it for awhile. Gregg Harry is looking into the possibility
of
measuring
the piece at MIT in between time.
In
investigating subsurface damage I have come across a technique called
Magnetorheological
Finishing (MRF) used by the national ignition facility. I have been
in
touch with the inventors of the technique and have explained our interest
in lowering
surface
damage. We are considering a trial similar to the ion beam etch, where
we will
supply
known substrates (probably the 3 x 1) and they will apply MRF and see if
they
can
remove the Bilby layer without changing other surface characteristics.
Disadvantage:
I believe the best microroughness achieved with this process is ~3A.
There
has not been a desire to do better until now, we don't know the limits
of the
process.
I would be interested in feedback from the group. If interested see the
NIF
paper
at: http://qedmrf.com/pdf/Boulder.pdfand
the QED website at
http://www.qedmrf.com
Speaking of ion beam etch we've received two etched fused silica wafers from CSIRO.
These were originally polished at Wave precision. One was etched on both sides with
~100nm removed. The other had the same depth removed on one side only. Gregg
Received those late last week and is planning to measure them. The 100 nm removal
depth was selected by GariLynn based on literature review of approximate Bilby layer
thickness. The NIF literature mentioned above came to light a bit later and suggests that
perhaps more removal might have been necessary.
Mechanical
Loss:
Sheila/Peter
Peter Sneddon has measured Q values of set of modes of
one of the 3" by 1" uncoated Corning 7980 (0A) fused silica samples after annealing in
Glasgow (to 1000 degs C reached over 4 days, held there for 4 days, cooled down in
stages over 18 days.)
Interestingly the frequency dependence observed is almost identical with are results
for
annealing at 980 C). However there seems a constant offset between the results.
Stanford:
Measurements of the elastic properties (a combination of Youngs modulus and density)
of a second Al2O3/Ta2O5 MLD coating were made - they duplicate the results from the
first sample of this type - so it does seem to look very different to the Al2O3/Ta2O5
Waveprecision coating. This needs some study to understand where the difference is
coming
from.
Ju
Li/David Blair: High Optical Power Test Facility Project Summary (
?? Thermal
lensing update
The
power supply Labview interface for the compensation plate is achieved.
A new
version
of the Mach-Zender interferometer to test the compensation plate is on
the way
(with
a friendly Labview user interface to simplify the measurements). First
tests must
begin
within 2 weeks.
Thermal
lensing will have negligible effect on the Gingin test 1 & 2. The test
3 (power
recycling
cavity added and 4kW circulating arm power) will be more interesting
regarding
the thermal lensing. The circulating power inside the PRC will decrease
of 10%
due
to the ITM thermal lens (mode mismatching). The arm cavity is quite insensitive
to
the
radius of curvature change of the ITM and ETM. The next step of the simulation,
will
include
the sidebands in the simulation (the program is ready but still under test).
?? Suspended
sapphire with groove and Nb flexure
Q-factor
measurement was carried out on the defective sapphire test mass, supplied
by
Crystal
Systems, with groove and niobium flexure. Its superside groove is
rough
and chipped. It is not possible to use point contacts, so edge contacting
has been
used.
This is expected to cause Q-degradation. Although this piece of sapphire
has
damaged
groove so the contact between the groove and the flexure is not perfect.
Preliminary
result show some modes Q-factor >107,
while others are degraded with the
lowest
down to 105.
The high Q modes are correlated with mode shapes with low
amplitude
at the suspension point as expected.
Rayleigh scattering map of the sapphire sample cross sections shows the presence of
significant large scale inhomogeneous scattering
structures within the sample.
?? Gingin
The laser enclosure/clean room construction has been finished. Leak detection finished
for South arm. Vibration isolation installation is expected to start after Amaldi
conference.
From: "Joseph A. Giaime" <giaime@lsuligo.phys.lsu.edu>
LSU SWG work summary:
Shyang Wen and the machine shops are preparing the seismometer mounts for the Tech. Demo. platform; Shyang will spend two weeks at Stanford early next month installing and testing them. He has also prepared the STS-2 locking devices, and will install them as well.
I've been working on reviews, papers, and retro-fit planning.
-------------------
From: Richard Mittleman <richard@ligo.mit.edu>
MIT Quad-Prototype
Andrew Thomas, a UROP student has taken over the Quad for the
summer.
As his senior thesis he is going to explore the global control scheme
of
actuating between the penultimate masses of the two chains. He
is
currently building some electronics to drive the coils and leds.
---------------------------
From: Janeen Romie <romie_j@ligo.caltech.edu>
NSF Review
All of us were involved in activities associated
with the NSF Review last week. The lab tour with all of the NSF reviewers
was a huge success. Calum and Mark showed them all the damped triple and
walked them through the background and main features.
Jim Hough, Ken Strain, Caroline Cantley, Sheila Rowan and Norna Robertson
traveled to CIT to support this review.
Mode Cleaner Controls Prototypes
Mark B., Ken S. and Calum have now successfully damped all of the modes
of the triple pendulum that are supposed to be damped. All have a settling
time of less than 10 seconds. Transfer functions will now be carried out
and compared with those measured in
A second mode cleaner suspension is in the process of being assembled. It is hoped that it can be fully assembled including the hybrid OSEMS in the next week or so. Janeen Romie has been working with Dave Robertson and Jay Heefner regarding the electronics for this suspension.
The
Quad Pendulum Work
Mike P-L has been working on the quad upper mass and has been interfacing
with the modeling folks like Norna and Calum to support this design. While
Norna and Ken were here last week, they met along with Calum and Mark to
talk about various aspects of the quad design.
Eddy Current Dampers
Calum has created drawings of the various light weight arrays that
we plan to test on a single pendulum. This will allow us determine if this
new design could be incorporated on an upper mass like the one proposed
for the ETM.
--------------------------
From: Steve Penn <penn@HWS.EDU>
Subject: monthly report to COWG & SWG
To: David Reitze <reitze@phys.ufl.edu>,
David Shoemaker <dhs@ligo.mit.edu>
Message-id: <BB1685EA.9742%penn@hws.edu>
MIME-version: 1.0
Content-type: multipart/alternative; boundary=B_3138815467_14922368
User-Agent: Microsoft-Entourage/10.1.1.2418
Content-Length: 3340
The Silica Research Plan has been
submitted to the DCC (T030102-00-R).
To support that work the NSF has granted me $80k for a vacuum annealing
furnace. I have located a few refurbished units that should fulfill
our size, temperature and vacuum requirements. I am in negotiations
with the vendor to strike the best deal. Delivery is estimated to
take 8 weeks.
Most of my work has centered around moving
lab equipment from SU to HWS and setting up my new lab. My coating
and silica measurements will soon occur there rather than at SU.
I have received a fused silica crucible in which to anneal our 3x 0.1disk
samples. I plan to test the disks for optimal anneal cycle and dependence
on annealing atmosphere. I also want to see if the crucibles provide a
good method of supporting and protecting the samples. That experiment will
begin by 1 july when the coating bell jar
is up and running at HWS.
Sasha is purchasing some ------------------------
Suspensions Report from GEO Glasgow
Mike Plissi
SUSPENSIONS
1. Quad Suspension Design
The design of the ETM upper mass is nearing completion with iterations
taking place between the Solidworks and MATLAB models. It exists in
two
forms with and without a rotational adjustment for the blades. The
basic
MATLAB model assumes a symmetrical arrangement and the addition of
the
rotational adjusters will cause off-axis effects that would require
some
investigation. Mike P-L and Calum Torrie will continue the design of
this mass and the upper intermediate mass during Mike's trip to CALTECH
next month. (M. P. Lloyd, N. Robertson, C.Torrie, J. Romie, M. Plissi,
C. Cantley)
2. Cantilever blades and blade wire clamps
The Youngs Modulus of a sample of blade material is being measured
and
the results from this investigation will be incorporated into the ANSYS
model for the blade designs.
The blade wire clamp testing has been completed and a report on the
results from these tests is to be completed in the near future. (M.
Plissi, E. Elliffe, M. P. Lloyd, R. Jones, C. Cantley)
3. Hybrid OSEMs
The manufacture and supply of 20 anodised
aluminium coil formers and 20
coil former clamps has been completed. The coils were cleaned, wound
and
tested in
The first six heads, required for the prototype that was connected
up to
the dSPACE, arrived at CALTECH on the 27th May. The remaining parts
arrived successfully at CALTECH in time for the NSF review. (R. Jones)
4. Eddy current damping tests
Horizontal transfer measurements have been taken with the eddy current
damper on the
involved acting on a 4 by 4 magnet array attached to the upper mass
of
the suspension. The results from these measurements will be compared
with a MATLAB model of the suspension. (M. Plissi, N. Robertson)
5. Advanced LIGO electronics meeting
This took place on the 21st May involving members of the
and members from
discussed were; noise in local control systems: Advanced LIGO
requirements and implications for Advanced LIGO operational modes,
current OSEM designs and performance and directions for sensor
developments. A near term development plan was decided upon and a
telecon, to report on progress, is scheduled for the 26th of June.
(Glasgow group, N. Robertson, D. Hoyland/C. Speake (Birmingham), N.
Lockerbie (Strathclyde University))
------------------------------
From: Phil Willems <willems@ligo.caltech.edu>
Sapphire Test Mass Q:
---------------------
Identifying the six modes for which we measured Q in the large sapphire
proved
to be more effort than we could justify. We tried Chladni style
experiments
using several readout schemes. The classic techique is to dust
the surface with
talc and excite a mode, watching the talc migrate to the nodes of oscillation.
But 40kg of sapphire is just too hard to drive that much. We
tried the
birefringent readout scheme a la
slightly wedged waveplate, and the data we got would ahve required
extensive
interpretation. A Michelson readout could
be rigid or scannable, but not both
(without much more work than judged worthwhile). So instead we
put a phonograph
styus on the mass and tapped it to find every mode predicted by Dennis
Coyne's
FEA model. Gregg has a student who will build a refined model
to identify the
modes and check to see if we can set any limits on the anisotropy of
loss in
sapphire.
Fused Silica Test Mass Q
------------------------
Initial LIGO has an uncoated spare ITM, labelled ITM11, made from Suprasil
312.
Dan Busby and I measured its Qs to go as high as 1.2e8, with many modes
above
the 3e7 value we used to honor. The data _roughly_ extend Kenji
Numata's values
and trend down to 11kHz. The puzzle
is that this mass was never annealed. The
complete set of Qs can be found in
http://www.ligo.caltech.edu/docs/T/T030087-00.pdf
Vertical Bounce Experiment
--------------------------
After a very long pause, we rechecked the Q's in the fused silica vertical
bounce experiment to be sure they had not changed. Then we replaced
the 1.5kg
bottom mass with a 105g bottom mass. This reduced the fiber tension
by nearly a
factor of fifteen, while changing the reduced mass of the vertical
oscillator by
only about 3%. The mode frequency thus shifted from 820Hz to
835Hz.
Unfortunately, this is a bit close to a strong 60Hz harmonic at 840Hz,
and the
suspension now appears to have another mode at 833Hz, making ringdowns
difficult
to measure. The Q of the vertical bounce mode is roughly 1e7+-30%.
For
comparison, the Q when the 1.5kg mass was attached was 1.2e7+-10%.
So if there
is a stress dependence to the loss in
fused silica, the data suggests that
stress at the 200MPa level changes the loss by 0 within +6e-9 and -6e-8.
I hope
to refine this number this week.
Interestingly, the frequency of the mode drifts up and down by about
.1Hz, a
fractional change of 1e-4, on rapid timescales- sometimes within 200s,
always
within 2000s. This could be consistent with 1K temperature changes,
but
temperature should not change that fast in a vacuum.
------------------------------
From: Larry Jones <ljones@ligo.caltech.edu>
A summary on the AdLIGO SEI structure contracting:
29 May 2003: bids received from 4 contractors: Alliance, HPD, Hytec & Stadco
6 Jun 2003: source evaluation committee met and found Stadco to be not competitive with the other three
13 Jun 2003: the three awardees are informed after teaming arrangements are clarified and Sanders makes the selection
17 Jun 2003: the three awardees agree to start work from verbal turn-on, with a nominal 2 month performance period
18 Jun 2003: attempting to schedule the Value Engineering Reviews (3);
will probably fit in the weeks of 25 Aug and 1 Sep.
Eric
had one vacuum pump fixed, switched with a second which went out for
repair. Worked on second draft of x-ray paper. Made more
progress in
search for glass, have pattern with significant glass-background- am
working
from there
Greg
- Prepared alloys and glass nozzles for casting
- New mold made to cast good size for Q factor measurement (took MUCH
longer than expected)
- Investigated filter for x-ray machine to filter out Iron fluoresence.
Solution is approx 30 micron Chromium filter, but cost is approx $1,500,
so we'll wait a little longer for the other x-ray machine (which doesn't
have this problem) to be fixed.
- Cast 1mm x 4mm x 40mm strip of each of the alloys. Although
spectum is still noisy, one looks crystalline, one looks like it could
be amorphous, and one definitely looks amorphous.
Hareem:
Learning about thermal noise by reading papers and relevant
parts of Numata-san's thesis. Looked at ANSYS to get a basic
understanding/ overview of the programme. Now waiting for Naumata-san
to
send me his simulation so that I can make a start at learning it.
Interacting with Enrico to learn the work he has done thus far,
especially Bench simulations.
Enrico
I continued the work with bench focusing of thermal lensing effect
and Gravity gradient noise. I studied the effect of finesse and power recycling
factor on the sensitivity. I've read the papers of Saulson and Thorne on
Gravity gradient noise and I added bench the possibility to plot this noise
for various beta together with the others in the sensitivity calculation.
Alessandro, Francesco F. and Francesco C.
Studying how to Ultrasound core the oriented sapphire sample provided
by Garilynn to carrot out thermal conductivity measurement rod samples
along the 3 axis.
Studying how to implement optical and electrostatical measurement technique
on Q-factor measurement setup.
Riccardo
Submitted to DCC the proceedings for the Elba 2003 Frontier Detectors
for frontier Physics
LIGO-P030040-00-D
for Bertolini's accelerometer paper, it can be found in
http://www.ligo.caltech.edu/~desalvo/bertolini-elba2003.ps
LIGO-P030039-00-D
for my paper on LF GWID
the pointer is
http://www.ligo.caltech.edu/~desalvo/DESALVO_ELBA_manuscript.doc
For additional information about this report, contact sanders@ligo.caltech.edu