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The LIGO Executive Committee
Agenda for Monday July 31, 2000 will be:
(Meeting time: 10:30 am Pacific Time)
Open meeting 10:30 - 11:30
Special Items:
No report this week
WBS 1.2 LIGO Operations--Administration
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. . .
| In | Out | |
| Packages | 44 | 12 |
| Faxes | 37 | 19 |
Press here to access the DOCUMENT CONTROL CENTER WEB PAGE.
From: Esther Cunningham <esther@ligo.caltech.edu>
Press here for ACCOUNTS PAYABLE HISTORY DATA.
From: "Brambila, Ruth" <Ruth.Brambila@caltech.edu>
No report this week.
Rita Torres
Progress Period from 7.21 to 7.27
Accomplishments:
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). Two change requests, those for cameras and projection systems are for information purposes only (they fall below the threshold for CCB review and approval) and will be entered into the budget baseline.
We are scheduling a meeting of the LIGO Change Control Board, Tuesday, August 1, 2000 at 9:30 PDT in the Science Conference Room (SCR) to discuss these change requests.
Press for the latest Contingency Needs Projection.
From: Kris Duncan <kris@ligo.caltech.edu>
From: Ed Jasnow <jasnow@ligo.caltech.edu>
No report this week.
General Items:
--------------
(F. Raab)
Today we have reviewed "lessons learned" from
the fire at Hanford. Here is my synopsis:
1. We were able to get emergency service people to let our key staff into
the area during the emergency, but it would be helpful to ask emergency
service people if some special ID should be carried by key staff.
2. We needed a walk-through of buildings to ensure that everyone working
on site knew that an evacuation order had been received. We are installing
an intercom, so that an evacuation order or instructions could be communicated
quickly site wide. We should also consider making the "crash phone" accessible
from the control room. We need to "drill" on these systems to ensure they
worek well.
3. LIGO had one of the few water storage systems of high volume for many
miles around. This water was used both to protect LIGO and to fight the
fire in surrounding areas. The supply with recharging running was sufficient
in this case. Nonetheless, it would be advisable to further increase water
storage on the site.
4. The firewater recharge system was started up by R. McCarthy to ensure
that we did not run low; there should be a procedure for starting up this
system so that other lab or fire personnel could do this in an emergency.
5. The extensive rock works surrounding the lab facilities and the tumbleweed
removal program played a huge role in saving the lab from harm. We should
whether the analogous systems in Livingston would be equally effective
given the variations in fire conditions likely in the terrain at that site.
6. We did not shut down ventilation systems during the fire; it would have
been beneficial to close the fresh air intakes in these high smoke conditions.
7. Telephone systems sufficed for outgoing calls from the site, but key
lab management could not be reached by phone for notification of the emergency
and attempts to call into the emergency area did not go through. We should
investigate if any special considerations should be given to radio or other
emergency contact devices.
I attended a meeting of the Port of Benton Commissioners that considered
the selection of a proposal to mine gravel in North Richland (approx. 10
miles from the LIGO corner station). I had earlier sent comments to the
commission explaining a concern by LIGO based on sensitivity to vibrations
from the mining operation and I advised them of the potential impacts for
Battelle's labs and other high-tech concerns. (Battelle personnel also
attended the meeting.) At the meeting we requested that if the Port went
forward with initiation of this mining activity that there be a mechanism
whereby we (or Battelle) could obtain mitigation of adverse impacts to
our operations. After some valuable discussion the Port determined that
they would select a contractor based on the proposals that were reviewed
and that they would begin negotiations of a contract to allow mining, but
that the contract should include language that would require efforts to
mitigate any adverse impacts on LIGO and Battelle from operations. The
commission sentiment was that if adverse effects were found and could not
be mitigated the Port would need to stop the operation. Battelle, LIGO
and the contractor were urged to work together to identify by measurements
or analysis any "show stoppers" during the several months that would be
required for contracting and licensing. (Translation: it could be very
expensive to uncover a huge problem later, so it is in everyone's interest
to make a good effort to find any problem now.) The selected contractor
was Eucon; ACME also submitted a proposal but scored lower in the evaluation.
I will contact Commissioner Ben Bennet for guidance on how to proceed with
contacts with Eucon while negotiations are in progress.
The Kamiakin HS SST team started seismic field measurements in the vicinity
of the ACME gravel mining operation in S. Richland to get some data on
vibration levels and how they fall off with distance from the plant.
In other news, people are busy prepping for WA4K installation.
Optics:
---------------------
(D. Cook)
COC and COS staging and preparations are on going. We began processes
the
ETM-4k optics and assembing the structures. Betsy and Anna have been
gluing
magnet/standoff assemblies for both the IOO and COC optics. We have
been
dusting the cobwebs off the gluing fixtures for the wire standoffs
and
magnets. Betsy and Co are also continuing the pick-off telescope assembly.
I made a mount to incorporate the "total station" theodolite on the
balancing optic table. This will add to the accuracy of balancing as
well
as allowing us to measure the wedge angle of the Core optics. (works
well
for LLO). Machined components for adapting the ETMx transmission monitor.
We should start installing light pipes over the PSL/IOO beam path along
with dedicated beam dumps. This is in hopes of reducing the amount
of
scattered light from coming back into the main beam as well as damping
out
accoustic noises and air currents. I have been sorting through the
optical
lever components and listing missing parts that we will need here for
the
4k installation and will send a shopping list to MIT. I am working
on a
design to adapt our current core optic shipping carriers to use them
for
the new LIGO sapphire Core optics.
FACILITY: Barry Barish visited the LLO on July 25 and 26. He met with
Key personnel and reviewed the on going activities at the site. Barry attended
a meeting with the architect for the staging building and auditorium and
participated in a conference call with the acoustics and special system
specialist(N. Traylor). The layout and seating arrangement for the auditorium
was reviewed and approved with comments. N. Traylor will provide a detail
layout and specification for audio/visual system for the auditorium. John
Desmond, the architect was directed to proceed with preparation of construction
document for the staging and auditorium building.
Erosion control contract is almost complete. Contractor is finishing
a few minor change orders. He has submitted the cost estimate for slope
stabilization along the borrow pit along the south arm.
Received the revised proposal for lease of the storage building and
forwarded it to Ed. He is in process of preparing the lease document for
signature
OPTICS/COC/SEI INSTALLATION: During COS installation we observed that
ITM-y moving around quite a bit, ~150u-rad. As we could find no reason
for this we elected to remove its Osems in situ and look for stowaway magnets.
In the process, a magnet was bumped and dislodged necessitating the removal
of the LOS. We will do this afternoon, and once in the lab remove all standoffs,
guide rods and magnets. They must be replaced, and the optic balanced.
We plan to get it in the oven this Saturday, permitting us reinstall it
late next week. This will delay the completion of the COS installation
until ITM-y is reinstalled. Mike Smith will tutor us before he departs
this week, so that we can begin alignment of the ITM-y PO telescope as
soon as the ITM is reinstalled. (Jonathan Kern)
PSL:We glued together a new Pre Mode Cleaner and installed it. We can
get 87% throughput with a 2 lens mode matching. We will continue to measure
the performance of this new pre-mode cleaner. We also glued together a
spare reference cavity with a PZT on one mirror.
We will use this as an analyzer cavity to measure the frequency noise
out of loop from the main reference cavity.(Joe Kovalik)
| Installation
& Commissioning:
Livingston |
Other Science/Engineering
Activities:
Issues/Concerns |
See also the Installation web page
Posts for in-vacuum Faraday isolator, a lens-holder-adapter, and a mirror mount standoff for the periscope were shipped this week to Hanford.
David Tanner and Malik Rakhmanov will be at Hanford starting July 31 to continue the 4k installation
During the MC alignment, MC2 was found to be out of balance more than the SUS controller could compensate for. We removed MC2 from the HAM and rebalanced it in the vacuum-prep lab to a balance angle less than 0.5 mrad. It's now being vacuum baked and is scheduled to be released on 7/28. Along with this optic, five 2" mirrors for the SOS optical levers, glass baffles for MC1 and 2, and a glass beam dump are in the same bake load.
We found that electrostatic charge on the mirror could cause the balance angle changes at various stages of the installation. A compact electrostatic fieldmeter and tester for measuring static charge potentials and testing ionizing devices have been located (thanks to Helena) and are being ordered to study and eventually solve this problem.
Mark Barton, et. al. discovered MC1 controller's pitch invert does not work. Russ is working on it.
The 40m Lab PSL optical layout is still being worked on, with the aim of minimizing the optical paths.
Placed the order for 6 (six) support piers for the photon calibrator. It is only a 2-3 week lead time(other vendors were 8 weeks). I received three no bids for the enclosure part of the assembly, so I have to rethink how I am going to enclose the assembly.
Supplied Doug Cook with the mounting hole locations for the Photon Calibrator.
4ITM04 is 2/3 through the measurement process in the metrology lab. The temperature is holding well even through this hot weather.
Linda Turner is in the process of putting all of the COC data packages on line. What a huge chore, thanks Linda!!
Peter Fritschel
Worked with Dale on the
re-design of the mode cleaner length/frequency controls electronics. Compared
to the (much modified) existing servo, the new MC servo will have lower
noise (so it doesn't compromise the frequency noise), wider bandwidth (so
we can attain a larger unity-gain-frequency), and have more built-in features
that we have come to desire (such as a gain stage resonant at the first
stack frequency; differential inputs and outputs for interfacing to other
systems). Some of the filters have also been modified, mostly to achieve
a more stable crossover between the MC length and PSL frequency control
paths.
I also worked with Sergei Klimenko at LHO to install his Wavelet-based Line removal code into the DMT libraries and with Christine to install some free-ware (including root) on the LHO license server.
Finally I updated the online documentation to describe a few features that were undocumented or inadequately documented.
Seiji Kawamura is visiting from Japan, and has been spending much of
his
time working with us on the TNI, which has been great. Seiji
helped us
implement a substantially improved crossover in our mode cleaner lock,
having the laser follow the mode cleaner at high frequencies and the
mode
cleaner follow the laser at low frequencies. The mode cleaner
now locks
very well and is nearly in its final configuration. Seiji also
tried
removing both our PSL and our broadband Pockels cell as an experiment
in
simplifying the interferometer. The system seems to work quite
well
without them, although we haven't yet determined the noise performance
of
the different locking schemes.
We have also been assembling our test cavities, with the goal of installing
one of them while Seiji is here. The physics shop finished our
magnet-gluing jig, and we glued magnets and wire standoffs on one of
the
mirrors (an end test mass). We have also been verifying and debugging
our
test-cavity OSEM controllers, and designing a satellite amplifier to
go
between our old-style controllers and our newer sensor-actuator heads.
The photothermal experiment is going well also. We have assembled
the
upgraded version, and we have both the pump beam and the probe beam
resonating in the test cavity, with the laser locked to the cavity
using
the probe beam. We are now in the process of hunting down noise
sources.
Mason:
Seismic Isolation
We have done an inventory of the seismic isolation parts currently
in
the LASTI lab. Basically we are missing all hardware (both in vacuum
and
out), The stack springs, seats, shims, scissor tables and translator
assemblies.
The first installation of a full HAM isolation with stack is sceduled
to
begin 9/11/00. Rich Reisen is shipping the LLO fixtures and will be
supplying assistance with the assembly. In place of the scissor tables
and translators we will be using dummies and adapters from the first
installations in Hanford.
Zucker:
Working on text description of experiment plan proposal and control
configuration diagrams for LASTI displacement measurement interferometer.
Assisted Ken Mason with parts tracking and logistics for SEI
installation staging.
Shoemaker:
Delivered second iteration of LASTI project plan to Tom Frey for
incorporation in overall LIGO II development plan.
More on the work done last week by Biplab, Rick and Brad.
They are looking into various noise sources of PSL using e2e.
Noise sources included are:
(1) shot noise, specially by the higher order mode (reference
has very small TEM00 light reflected)
(2) noise caused by the guoy phase change due to the
longitudinal motion of the detector (waist
size is
very small and small longitudinal motion could
cause
larger effect than large size field)
(3) finite aperture size of the detector which introduce
noise coming from the higher order module
due to
the coupling of TEM00 and even higher order
modes.
Lock Acquisition
A bug was found in the simulation code related to the misalignment
of the mirror. This needs to be fixed to evaluate the effect of mirror
misalignments on the locking procedure. Biplab is looking into it.
Adlib
Three new supports were added. One is a support of macro. Throughout
the configuration, one can use a descriptive name, like armLength,
in
stead of numerical values. A file named e2eDB.dat is used to keep
macro definitions, (name, value, unit and comment). System wide macro
file containing major LIGO parameters will be provided, but the user
can have his/her own in their directory, which can override the system
wide definition.
Second, anywhere numerical values are allowed, mathematical expression
is allows, like 2*atan(L/z0), or sin(PI/3+eps), this makes it much
easier to
enter numbers and understand the meaning of it.
Third, a new primitive group FUNC has been introduced. This primitive
can be used to almost arbitrary math manipulations of multiple inputs
to multiple outputs. Sometimes, simple math needs very complex module
connections, but it is over now.
Computing
sargas, our main compute server, was very busy this week by many users'
heavy
use, and building the simulation engine and GUI program took so long.
This makes development/debugging works very difficult, not to mention
the
simulation run itself. As a temporal solution, we are looking into
using
those
ldas group computer (Pentium) which are not used now.
Software Systems (Blackburn)
Kent reports that the LDAS software environment has been successfully built and installed and is operational (in its present state of development) at Penn State and Milwaukee.The development activities for the dataConditionAPI dominated the activities
within the group this week. Next week is the Mock-Data-Challenge (MDC) for
this subset of LDAS. We have successfully integrated the C++ code jointly
authored by CIT, PSU, UTB, and ANU with TCL and created a dataConditionAPI
LDAS API that is now running within the LDAS system here at CIT. Only a limited
number of actions are fully supported at this time, but the plan is to have
the full compliment of actions needed to support the MDC ready by start of
business on Monday. Earlier problems with the datacon quad Pentium III box
seem to have cleared up for undefined reasons by mid week. We will continue
to watch this unit and keep the dataConditionAPI running prior to the MDC to
assess any further Unix level problems. The dataConditionAPI MDC will begin
Monday Morning with an 8:30AM kick-off meeting with the LDAS group.The wrapperAPI was successfully run on the small 16 CPU cluster here at CIT
this week. It was only run with a very small CPU load on each slave. A bug
was found which caused heavy loading of the slaves to fail during comunication
of results back to the master. This problem is being fixed and we will re-
test the wrapperAPI with heavier loading of slaves. Results of the first
runs of the wrapperAPI on the beowulf showed several interesting things:
The 333MHz dual pentium II nodes are 3x faster than a 700MHz dual pentium III
unit recently purchased (this may be a linux kernel configuration issue). Also,
the tests indicate that the wrapperAPI, even though it is performing at close
to the expected rate on each slave is rapidly becoming communication bound when
the load on each slave is a small as current code is supporting. Attempts to
identify why the wrapperAPI is not running at UWM have not turned up any
possible explanation. However, the wrapperAPI was successfully run on a unique
platform other than the developer's environment this week. Efforts will now
focus on removing the bugs which constrain the amount of loading of the slaves
and reducing the comminication overhead for sending results back to the master.A test script which starts each LDAS API up and measures CPU and memory
utilization has successfully be tested on a single workstation. It will now
be upgraded to allow remote startup of APIs and logging of results in a
standard format which will allow the next generation of the script to
automatically compare current test results to previous results and in an
even later version, to be able to produce trend results for these API tests.LDAS staff also worked on the new CDS DAQs system installation at Hanford and
added a new frame reader to the NDS which supports the latest version of the
C++ Frame I/O library (FrameCPP).Another area of focus this past week has been on improving the build process
for LDAS software. Attempts to build the system at outside facilities have
resulted in lots of feedback and identification of subtle issues which have
tremendous impact on the successful build of the software elsewhere. A new
link has been added to the LDAS webpages which is slowly beginning to
capture all the information necessary to successfully build ldas software.
Hardware Systems (Anderson)
----- Forwarded message from Omar Rashad (LDAS SysAdmin) -----
In preparation for MDC:
Installed new ftp daemon on ldas-dev.
Added and stabilized an external ethernet interface for datacon.
Added mdc account to datacon.Reconfigured procurement gnats:
Turned off default view access.
Added suspended state.
Added lazz to notify list.
Correcting bug which is forcing unintended changes upon any editing.Reconfigured ldas gnats:
to provide Peter and Isaac edit capabilities.
Creating testing category.Dropped new/re-dropped Cat 5 cables to and reorganized other aspects of
the Millikan machine room.Installing apache on the new ldas.ligo-wa
Installing mpich into ldcg.Upgraded:
datacon with all applicable updates except kernel.
linuxbox1 with all applicable updates which also created problems with
sshd.
Jeff Edlund (FCT):Data Analysis Activities
MIT:
Received the new disk drive system.
Livingston:
Nothing to report.
Hanford:
(Christine)
Continued installing new software on the license server. Started
organizing computers and hubs for the staging building for the LSC
conference. Set up two new PCs and ordered more PCs.
CIT:
(Sam)
- Patched all the sun boxes that I could with the patch necessary for
star
office. This is in preparation for staroffice installation on the network.
- Installed a new switch box. Installed the basic s/w on a couple of
PC's.
- Worked on documentation
- Worked on minor pc problems
- Worked on the purchase of various pieces of equipment for general
user usage.
(Barbara)
- Continued working on the web forms for LSC documents. Installed
new
forms and web pages on the public server. Tweaked the Access
forms and
reports. Updated the backup script. Spent time tracking down
and fixing a
bug that Norna Roberston reported.
- Continued working on costbook reports, both the printed and web versions.
- Made miscellaneous changes to the LDAS web site and LIGO site.
(Lisa)
-Did a flash prom updated on graffias (ultra2). We know have
an entry in our
faq detailing how to do that.
-Backups. On our daily and weekly backups we can no longer fit
everything on
one tape. I've been looking at the scripts running on rastaban.
At this point,
I think our best solution is to split the backup across 2 tapes for
the dailys.
The weekly's would need to be scheduled off a different host -- probably
mizar,
until we can get the new tape robot on line.
- Started the monthly backups this morning. We have 5 drives
going at full
force. I am testing out our new portable tape drive, so we will
have 6 drives
devoted to the monthly once I get it up.
- Documented the monthly backup procedure. I renamed the scripts
to be more
obvious. I have a chart of what goes where. I have not
yet added comment lines
to the scripts themselves or dropped a readme file in the directory,
but I will
as soon as I'm certain that everything has worked well.
- Created some new accounts. I have a checklist now of what to do when
creating
a new account.
- Got a quote from Cisco for the remote access router 3640.
- Learned how to add users to the dial-up pool.
(Larry)
- It appears that most of the SUN equipment will start shipping the
first of
August. We are working on the logistics for all of the equipment that
will have
to be assembled and installed.
- Working with Lisa on a number of projects including: Single mode
fiber to
Multimode converter installation at Wilson House, new backup scripts
and
procedures, installation of Cadence, getting a new modem pool unit
to allow
higher connection rates and allow a smother transition to digital services.
- The licenses for Office 2000 have arrived but we are still
waiting for media
and reference material. Barbara and Larry will be doing some of the
upgrades/installations but most will be done by Samantha.
- Another virus has popped up, it infects word and excell documents.
Basically
it causes characters in the documents to no longer be visible on the
screen. The
latest virus-scan s/w does fix the problem documents.
- Working a number of minor purchases and contracts.
- Resolved a number of PC and SUN issues for different labs.
- Still working budget issues.
Bruce Sears:
- Discussed latest on VRVS with Julian Bunn, contacted Harvey Newman,
et al
about setting
up a demo of the system at HEP.
--
Nergis Mavalvala
We have begun revisiting the modal model, implementing the signal
extraction mirror
for alignment sensing for the LIGO 2 ifo (with Daniel).
Peter King
LIGO II PSL
A second draft of the LIGO-II WBS Dictionary is being worked on.
At present I'm having some difficulty, mentally at least, separating
the
parts of the PSL from the parts of the LIGO-II Laser given that the
current
PSL conceptual design calls for a laser pre-modecleaner
Bill Kells
Some considerations of LIGO II thermal/sapphire issues.
Some consideration of the 40m (upgrade) configuration (optics).
From: Helena Armandula <ahelena@ligo.caltech.edu>
LIGO II coating activities:
Received coated samples from GO.
They experienced a deposition monitor failure during the run that caused
the coating to peek at 1100.8 instead of 1064.
They used Ta2O5 and Al2O3 as coating materials.
The plan is to send the samples to Stanford to be characterized for
absorption. The high transmission (500ppm +) restricts the ability to evaluate
them at Caltech.
Received coated samples from MLD. Jordan will look at them.
Confirmed meetings with JM Mackowski (Virgo) and R. Lalezari (REO)
to discuss their possible involvement with LIGO II coatings.
From: Mike Zucker <mike@ligo.mit.edu>
LIGO II ISC:
Met with proposal ISC team to flesh out controls implementation
features, and principally, differences with respect to direct LIGO
I
scaling of electronics and networking. Discussion flushed out
a need
for converter, DSP and filter development activities, which were then
added to the WBS.
Reviewing (with P. Fritschel and others) the gamut of proposed DR/RSE
modulation & sensing schemes presented by Mason, Delker, ANU etc.
to
develop an "envelope concept;" a superset which (by brute force) can
very probably be made to work (though perhaps not elegantly or
efficiently). This can thus stand in (e.g., for costing and planning
purposes) while the search for the best design continues. Meanwhile
we
expect more progress in that search from the configuration meeting
week
after next (@ MIT) and the LSC meeting the following week (@ LHO).
Also started discussing (with S. Richman and J. Giaime) the effect of
likely residual RMS motion of SEI platforms upon various IFO degrees
of
freedom, to try and roughly bound loop gain requirements (loop gains
in
turn drive noise couplings for auxiliary degrees of freedom, a big
discriminator between readout schemes).
LIGO II AOP:
Working (with R. Lawrence) on requirements basis for LIGO II adaptive
optics compensation.
From: Phil Willems <willems@ligo.caltech.edu>
Fused silica fibers/ribbons:
----------------------------
Experimented with a variety of torches in order to find one that is
optimal for
fused silica ribbon pulling. None so far are ideal. (John Johnson,
Phil
Willems)
Built and tested electrostatic driver for fiber Q tests. Found
many of the
lowest-order modes of a test fiber using ESD and quad PD readout.
Built a
mounting clamp for fiber Q tests. (Virginio Sannibale, Phil Willems)
Hydroxy-catalysis bonding:
--------------------------
Received shipment of new fused silica substrates from GO for more bonding
tests.
Prepared two more bonds for a loading test. (Helena Armandula)
From: Janeen Hazel <romie_j@ligo.caltech.edu>
Suspensions - Thursday, July 27, 2000
Working on LIGO II Proposal.
From: "Ryan C. Lawrence" <rclawren@ligo.mit.edu>
Active Thermal Compensation
This week I put together a quick and dirty servo loop to intensity
stabilize the CO2 laser. With the now-steady beam, I've begun
taking
measurements of the impulse response of the test optic. On the
simulation
side, I'm just about done finding the correcting OPD's (for a ring
heater actuating on fused silica optics of various sizes) to be included
in Melody. I've got Phil working on a finite element model to
find the
bulk impulse response of an optic (thermoelastic effects, in particular).
He's also working on improving the intensity stabilization of the CO2
laser. Dave is working on analyzing the ring heater data, and
is now
taking more data at higher heater power.
From: GariLynn Billingsley <Billingsley_G@ligo.caltech.edu>
There was a meeting at Veeco last week to discuss upgrades/options for
the IR interferometer used in the Metrology lab. Veeco will quote,
by August 16 2000:
1. Implementation of an external laser source, fiber coupled to the
instrument
2. Installation of a 10 bit or better digital IR camera. A camera
has not been identified, this may turn out to be a research project.
3. Stepping the initial phase for averaging of multiple data sets.
Analysis indicates that data may be strongly dependent on initial phase,
because of the non-sinusoidal fringes in the HR-HR cavity.
4. Raising the resonant frequency of the pellicle by replacing it with
a smaller aperture pellicle. To completely eliminate the pellicle
would require an entire re-design of the package.
New systems (which include #1 already) cost ~180K
Veeco was able to answer some questions about the sensitivity of their
instruments to vibration. The following picture shows the sensitivity to
vibration (out to 50 Hz) of a Veeco interferometer. The series are different
phase unwrapping algorithms. Ours is the 12 frame (blue) The file is posted
at:
http://www.ligo.caltech.edu/~gari/Supporting/VeecoVib.JPG
This is not the same instruments as ours (though similar.) This is
the work of Joanna Schmit at Veeco
The second 15 cm x 8 cm piece of sapphire shipped to CSIRO for homogeneity
measurement.
From: Riccardo DeSalvo <desalvo@ligo.caltech.edu>
Removal ongoing, IP mostly rebuilt.
Welcoming Francesco.
Chenyang
Measuring Q factor of mirror actuator LC circuit in different way to
offset effect of oscilloscope’s cable stray capacitance.
Actuator’s report OK except for figure captions.
Akiteru, Szabi
Characterising TAMA IP, optimizing shaker
Obtained 60 dB at low frequency, plateau at >=40 dB at high frequency
(above 4to5 Hz). Non fully optimized counterweights and accelerometer
transversal sensitivity may be limiting performance.
Alessandro.
Electropolishing of 5000 series aluminum OK on samples but not good
in
2000 series. Consequently the 4 accelerometers are being machined out
of
CuBe where electropolishing is much easier. R/O Electronics proceeding
OK.
Hareem
Measured Q of 50 at 170 mHz on GASFs, Q vs. Frequency curve almost
ready.
Thermal drift measurement setup almost rebuilt for further tests and
bimetal blade compensator tests.
Soy
Assembled U.S. isolated stressable blade for US acoustic emission
measurement.
Verified isolation from external noises, debugging signal, preparing
triggers optimised for high frequency US events. DAQ through
digital
tektronics scope on HF and LF band contemporarily. Francesco
will
assist on DAQ programme.
Lisa
Found some correlation between in oven/out of oven temperature.
Breakdown in oven air re-circulation system repaired. Starting
measurement of LVDTs inside oven but Windows is unstable; possibly
a
virus? Virginio prescribed reinstallation and purging of all
junk
programs. Temperature DAQ new version, LVDT acquisition with
Labview
with Soy’s assistance.
Susha
Back in the dark with MGASF simulation, Francesco that discussed the
problem with Giancarlo will help.
Gilberto
Delivered the 3+1 LVDT in+outside the oven. A (different) LVDT
broken
needs rewinding.
Some connection problems with R/O cables and electronics.
James
Reproduced Kenji’s 50+ db transfer function for 1.5 mm MGASF as before
first visible resonance above 100 Hz, Blade’s internal resonance not
transmitted to payload by blade’s symmetry. Going for vertical
to
horizontal coupling studies.
Soon will need single wire suspension to replace the present 3 garage
spring geometry.
Virginio
Always spread thin.
Not received yet VME crate, last missing part to complete second DSP
acquisition chain.
Brett, Virginio
PCB for stepping motors debugging, ready for production of 20 boards
end
of week.
Riccardo
IP mechanics, stepping motor installation.
Szabi
Re-aligning LIGO IP after removal, investigating sources of small leg’s
misalignements, mostly on the support plate or the base towers and
in
the flex joints themselves, not in the legs.
From: Sam Richman <srichman@ligo.mit.edu>
Stiff isolation system (Sam Richman, Shourov Chatterji, Wensheng Hua,
Brian Lantz)
The low-frequency tilt-horizontal coupling seen in the prototype is
not (mainly) due to transverse forces from the actuators, as we had previously
guessed. It is the anistropic nature of the blade springs, together
with the fact that flexures for horizontal compliance are mounted vertically
offset from the blade tips by a significant amount, that causes a coupling
to tilt when a stage moves horizontally. Sam continues to work on
controllers using the integrated sensors, and Shourov is testing the new
cooler (temp. and otherwise) forcer drivers. W. Hua and B. Lantz
(Stanford) have been modeling tilt-hor. effects in the prototype.
For additional information about this report, contact sanders@ligo.caltech.edu