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The LIGO Executive Committee
Agenda for Monday December 4, 2000 will be:
(Meeting time: 10:30 am Pacific Time)
Open meeting 10:30 - 11:30
Special Items:
All LLO in-vacuum components are installed and aligned!!
no report
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. . .
| Packages | Faxes | |
| In | 73 | 63 |
| Out | 22 | 71 |
Press here to access the DOCUMENT CONTROL CENTER WEB PAGE.
From: Esther Cunningham <esther@ligo.caltech.edu>
Press here for ACCOUNTS
PAYABLE HISTORY DATA.
| Date | Incoming Invoices And Receivers | Wires | Large Contract Invoices |
| November 17, 2000 | 11 | 0 | 0 |
| November 20, 2000 | 8 | 0 | 2 |
| November 21, 2000 | 5 | 0 | 0 |
| November 22, 2000 | 4 | 0 | 0 |
| November 27, 2000 | 15 | 0 | 1 |
| November 28, 2000 | 8 | 0 | 0 |
| November 29, 2000 | 18 | 0 | 0 |
| November 30, 2000 | 5 | 0 | 0 |
| Totals | 74 | 0 | 3 |
From: "Brambila, Ruth" <Ruth.Brambila@caltech.edu>
From: irena@ligo.caltech.edu (Irena Petrac)
Rita Torres
Accomplishments:
WBS 1.4.1.2 Project
Controls (LIGO Construction)
Annual Report: There will be an Annual Report due as of the end of November. I will be requesting inputs from the usual bunch mid-December after the dust from the proposal has a chance to settle a bit. I propose to keep this report moderate in size, about the size and complexity of a Quarterly Report, to minimize the burden.
The following Change Requests have
been submitted:
| CR-000018 | WBS 1.1.4 | Curbing for Service Roads at Livingston | G. Stapfer |
| CR-000019 | WBS 1.2 | Additional Lab Equipment | D. Coyne |
Press for the latest Contingency
Needs Projection.
From: Kris Duncan <kris@ligo.caltech.edu>
From: Ed Jasnow <jasnow@ligo.caltech.edu>
General Items:
--------------
(F. Raab)
Main commissioning activity is to get reliable
locking of full interferometer with no damping in arms. We have Henrich
Heitmann and Simon Mataguez visiting from VIRGO.
Seismic Systems
---------------------
H.Radkins, M.Guenther, G.Moreno
CAS: The Coarse Actuation System is being tested on BSC2 now.
Rack
modification for air filtering is being planned for the 4 channel rack
to
improve our air pressure budget. The Database on the two channel
rack is
being updated to allow start up on BSC1 preventing inadvertent disturbance
of BSC8. The Coarse Flexure yawing problem is being studied as
we have
exhausted the obvious corrections which have only yielded about %50
reduction of yaw.
Fine Actuation: Stands are being built to hold the Fine stage
PZT
controller racks. The stands will put the units at a more convenient
height, shorten cable runs, and allow cleaning underneath. The
wheels are
in motion also to get the PZTs under command from the control room.
ISC
----
(H.Radkins, D.Cook, C.Gray, G.Moreno)
Optical Levers: Modifications are being made to the Optical Lever
Boxes to
accommodate the new LASER. The Optical Lever Receivers are getting
their
QPDs output increased whenever the EE shop can fit them in; we're about
at
%50 completed now.
One box left to modify to get the orientation correct.
Examined beams of ITMy Optical Lever. As suspected, the 30x beam
expander
produces a beam too large not to be clipped by the 1.5" mirror at 45°.
At
the receiver though, the beam is not obviously clipped. The real
issue of
this problem is that any time the Transmission steering mirror is adjusted,
the calibration (pitch -vs- yaw) may change because the beam shape
changes.
More tests are needed.
Initial Alignment Monuments: The End station monuments have been
completed
and the LVEA monuments still need a couple days work. Testing
is ongoing
to determine the stability on the resilient floor under the surveying
stands.
Optics:
-------
(D. Cook)
The 4-K COC suspensions are now complete with the exception of the BS.
The
beam splitter is waiting for the next available vacuum bake oven opening,
followed by being re-suspended. All of the 4k suspensions are being
stored
waiting for the OSEMs to arrive and be installed. We will then measure
each optic for its reflectivity and wedge angle. We are having the
PAM
brackets modified to allow for the additional clearances needed for
the new
shadow sensor configuration and will go into the vacuum bake oven Friday.
The PAM screws are currently in the vacuum bake oven.
We are modifying the 4k optical lever transmission enclosures to
accommodate the new lasers. Tooling is being made up to assist with
the 4k
installation and alignment. The installation procedures still need
some
updating as yet. We are in hopes of have most of the COC, COS and IAS
components for the entire 4k installation ready prior to venting the
system.
Controls:
---------
(D. Barker)
Building the 4k PSL EPICS VME controls system. Also building 4k 1X5
ADCU
system for accelerometer acquisition.
Updated all LHO EPICS databases with the PINI fix to remove the
save/restore "stuck button" bug. I will do the same at LLO.
CDS bug list is being reviewed and ported over the GNATS system.
Cybernetics tape robot has returned from repair and is being installed
as a framebuilder trend data backup service.
EDCU CPU freeze-up bug still exists, but is occuring less frequently.
I
have installed a VME reset card in the DAQ controller crate and wrote
software to automatically reset the DAQ when the EDCU is no longer
available.
New web EPICS service is now online on
http://blue.ligo-wa.caltech.edu/perl/epics.pl This acquires over
4000
channels of epics data for realtime viewing. Channel selection is either
via pattern matching, sub-system selection or "medm" look and feel.
In
addition, an hourly trend service using the autoburt hourly backup
snapshot data files is available (outputs as comma delimited text file).
Due to large amounts of data being generated by analysis tools,
hanford1's disks have been filling up. I have moved applications around
and have establish disk quotas for user accounts.
Detector Installation: We have the mode cleaner locking reliably again. The output beam however has changed and we are not sure why. It is being monitored now, but is not showing any steady drift in position. The internal Q's of the mode cleaner mirrors were remeasured. MC3 has a split resonance at 28 kHz with one peak showing a much lower Q than the other . This is being checked. (Joe Kovalik)
OPTICS/COC/SEI INSTALLATION: The realignment of ETM-y and the Y-end Arm Cavity Baffle has been completed. The baffle's position was marked and it was then removed and stored in the manifold. This is an LLO milestone; all of our in-vacuum components are installed and aligned!! We've received the new OptLev lasers and replaced those which had failed. All CO Optical Levers are enabled and their signals are in the Control Room. Laser Safety boots are installed site wide, with the exception of the ISC tables at HAMs 1, 3 and 4. Our next task is the coarse alignment of the Michelson. Even with the MC alignment problems, we're seeing reflected beams from both ITMs using a video camera at the darkport. Joe Kovalik assisted Gary Traylor, Joe Hanson and myself in installing and cabling cameras to view MMT 1, 2 and 3 as well as the RM yesterday. (Jonathan Kern)
We have installed cameras looking into viewports and then run temporary cables into the video inputs to the mass storage room. We can now see MMT1, MMT2, MMT3 , RM and the anti-sym. port in the control room. This will allow us to align the Michelson from the control room.
We are also trying to have more of the activity managed through the control room. This is imperative as LLO is now becoming too large to have one component changed without affecting another.
A comparison test was conducted involving the Facilities Monitoring
System's relative humidity monitors and a Kahn-Cermet hygrometer due to
the
fact FMS RH readouts appeared to be higher than anticipated. The results
have been given to Gerry Stapfer for disposition.
FMS RH monitor
X-end 63.6%
Y-end 47.1%
LVEA 49.0%
The Power System Inc. RH transmitters were in-factory calibrated before
installation, the Kahn-Cermet hygrometer had been calibrated earlier this
year. (Rich Riesen)
Computing: We are working on the installation of our tape robot,
and trying to put it on a machine where it can be reached from either the
GC or CDS network.We have received the parts for our upgrade of the web
and e-mail server, and are installing them and preparing for the change.
We are working on preparations for the conference which will be here in
two weeks.We are setting up a new workstation and modeling software for
a new engineer. (Shannon Roddy, Tom Evans)
| Installation
& Commissioning:
Livingston |
Other Science/Engineering
Activities:
Issues/Concerns |
See also the Installation web page
Nergis
Mavavala, Rai Weiss, Mike Landry, Bill Kells, Stan whitcomb
We
have been working on getting the lock acquisition code ready for another
attempt at full interferometer locking. The changes since the last such
run that we hope will help
a)
improved handling of saturations by the coil drivers
b)
feedback of common-mode signal to laser frequency
c)
lower gains on transmission QPDs to avoid saturation when power builds
up
d)
3x3 matrix inversion in Matt's code
We also spent some time resolving a discrepancy between the ETM actuator calibrations done before and during the E2 runs. We found the E2 calibrations to be correct, but discovered en route that the AS_I sensor signal form the two arm cavities were different by about 80%. After accounting for differences in drive strengths of the two ITMs and about 30% difference in the alignment/mode matching of the two cavities, we are still looking for a 30% difference between the discriminant from the two arms. We also found that the AS_I signal from the Yarm responded in a peculiar way to adjustment of the RF phase: the phase shift that minimzed the cavity error signal in AS_Q was at least 50 degrees away from the phase that maximized the cavity error signal in AS_I. The Xarm behaved much better, the minimum (maximum) for AS_Q (AS_I) occured at the same phase. These effects are being investigated further.
Rolf Bork
Completed requested changes
to LSC software (add anti-whitening/dewhitening digital filters and lock
input matrix copy to op input matrix). Addition of 30 second order
section (SOS) iir filters only increased LSC processing time by 3-4 usec.
The total number of SOS filters in the LSC code is now up to 95.
Plan to visit LHO 12/7 thru 12/13 for further LSC testing.
Bill Kells
Reved up the latest e2e
model versions now resident at Caltech, in prep for the next full ifo locking
sudies at LHO.
John Zweizig
This week I have started
preparations for a rerun of the E2 data through all trigger generating
monitors to get a complete and consistent set of triggers. I have modified
the shared memory partition code to add a partition-wide parameter that
forces all consumers to receive all data. This will insure that all monitors
in the rerun will receive all the (reduced data set) frames. About 5-6
monitors have been submitted for inclusion in the rerun including monitors
of lock acquisition/loss, servo peaking, seismic rms, glitch detection,
and data consistency. One or two remain in the pipeline. I have also been
modifying the trigger manager to selectively enable/disable writing of
triggers. This will be used to prevent logging of triggers in the meta-database
during development and debugging of the monitors.
Szabi Marka, Akiteru Takamori,
Daniel Sigg
The raw data files for the
DAQ timing (based on the RAMP/TRIG) monitors are available from the E2
homepage (http://blue.ligo-wa.caltech.edu/engrun/E2/Results/EtoE_Timing/).
I have been checking some queries asked about the "wirelist" sent to LHO for fabrication of the PSL rack cross-connects. Questions concerning the wirelist, used during the fabrication of 2X7, related to the wiring for the RF photodetectors and VCO. Said connections were retro-fitted in the field to the cross-connect, so the construction wirelist did not indicate these connections. A small change was made to accommodate the new-style of LSC RF photodetector.
Alignment of the optics downstream from the MC is now our highest priority. We have encountered some problems. Controllers for many of these optics seem to be switching autonomously into a state where the optics are not damped and where the MEDM screens do not function properly. There was also an unexplained shift in the alignment of the mode cleaner, of an amount large enough to force us to redo the alignment of the MMT.
For the past few weeks I've been trying to sort out a design for a low-noise, high power photodetector for use in the intensity stabilization servo. At present I have a rough schematic of a circuit, with components, that I wanted to get some advice from Rich on, just in case the scheme was lacking.
Rick Karwoski, Paul Russell
Pre-mode Cleaner stuff...
Frequency Stabilization...We have completed bench testing the three pre-mode cleaner circuit boards. The photo-diode and frequency reference modules have been shipped to LHO. We are holding the PMC servo boards temporarily for additional tests and review of critical circuit areas. It will be shipped tomorrow.
General...Parts Kitting is in process for the frequency stabilization modules. RF Photo diode module testing has begun
We continue to tidy up fix discrepancies on the documentation relating to the boards and cross connect wiring
Mohana Mageswaran
I am testing my new MC Servo
Board.
Nilesh from Surmet has reported a problem that his subcontractor is having with the surface finish of their parts. He reports that with the current set-up a 16 surface finish is not possible. We will have a telecon later this week to work out solutions to this.
Peter Fritschel
Myron and I have begun to
screen the LEDs and PDs to be used in the new osem heads. We have seen
a fair amount of variability in the LED ouput beam direction, which leads
to variability in the PD photocurrent; some errors can be overcome by non-parallel
positioning of the LED/PD boards, but we may just have to reject some LEDs
that have larger beam offsets.
Since our last report we have constructed and installed all the necessary
hardware for the second and last of our test cavities. We repaired
our
last OSEM controller and can now damp all seven suspended optics
simultaneously.
We also installed all of the remaining mounts and mirrors inside the
chamber and began aligning them, and we rebalanced the seismic isolation
stack to accommodate the added weight of the new hardware.
We have completed the electronics necessary for locking our laser/mode
cleaner system. (The mode cleaner is locked to the laser at low
frequencies, and the laser is locked to the mode cleaner at high
frequencies.) These electronics replace a string of SR560 preamps
and
passive filters that we had been using. Initial tests indicate
that the
new module is functioning properly, but a conclusive test will have
to wait
until we have closed the chamber.
Many thanks once again to Jay Heefner, Shaun
Rahimi, and Lori Robison for
all their help. Their efforts has been
invaluable for both our active damping
and our mode cleaner servo electronics!
LASTI (Zucker, Mason, Kruzel, Smith, MacInnis, Shoemaker)
----------------------------------------------------------
Ed K. is finishing up the drilling and concrete roughening for
the BSC piers this week. We will bring in a cleaning crew next
week to clean up before we go back and finish HAM21 internal
seismic installation.
Ken M. has been working on design ideas for the BSC cleanroom.
Mike Z. has been tweaking the vacuum system so we can try some
enhancements (second backing pump etc.) on the next bellows
leak check.
Biplab worked on noise curve generation. He is introducing violin modes.
He is also studying the lock-acquisition with misalignments using new
improved version of Han2k model.
He is writing a draft of E2E's first paper.
A new version of modeler/modeler_freq has been released and is installed
at CIT. A tarball is available from the e2e home page. This version
is
necessary to simulate the latest Han2k model, which uses the latest
LSC
servo.
* Simulation code
Two efforts started toward the implementation of threads in the simulation
engine. One is a generic parallelization scheme in the primitive module
level, and the other is case-by-case works in specific part of the
code.
(1) genetic - Matt wrote a exectuteNode class, which takes care of the
data flow connection. In adlib, each module will create and talk to
an
executeNote object. Tavio is working to write a testbed using this
class
and his thread-safe queue class with a simple input. This testbed will
be
used, not only to validate these queues, but will be used to develop
algorithms to optimize the use of threads.
(2) specific - Matt wrote a generic thread-wrapper object, Runnable,
which
automate many of the tedius things to do with threds. Hiro used that
to
make "printing action" to be executed in a separate thread. Hiro is
now
working to parallelize the michelson summation cavity so that all
sidebands are simulated in separate threads. (The discussion about
this
motivated Matt to write Runnable class.) Right now, this primitive
is the
heaviest, and only one heavy module, and this parallelization will
be most
effective right now. In the long run, when more heavy modules come,
the
first parellelization is more important.
* ALFI (GUI)
Ed and Bruce worked hard to stabilize alfi and new version has been
released. It has been installed at CIT, and other sites can download
a
tarball from e2e home page.
The priority of the features requested were discussed. First all items
which do not take much time will be resolved. Then, multiple item
selection, group move and copy will be worked on. Following that is
to
implement a node point. The direction marks on lines is defered to
be
discussed after the next wxWindow is incoporated in alfi.
Software Systems (Blackburn)
The major modifications presently occurring within the dataConditionAPI
to implement and use a new Unified Data Type (UDT) are proceeding at an
increasingly progressive rate. Several of the previous algorithms have
been ported over and testing programs updated. There have been a few
little problems associated with the changes to the build scripts that
have caused nightly builds of the LDAS to fail. These bugs are fixed as
soon as they are identified. But the change to support a UDT are clearly
not isolated to the dataConditionAPI to an optimal level.Work has also begun on the supporting functionality to convert LDAS
ILWD data types used throughout LDAS for data communications into the
UDT Scalar<> and Sequence<> classes. Work on converting UDTs into the
LDAS ILWD will begin next week.The LDAS automated C++ documentation construction based on the new
perceps is now nearly complete. A few pages are failing to be generated
properly and fixes are expected in the next week or two.In the wrapperAPI development there have been several problems to show
up over the past week. The error handling between MPI master and slaves
had to be modified again to better handle the possibility for the slaves
to run away when errors occur. The second major problem is still open
and involves a lost socket communication of messages between the mpiAPI
and the wrapperAPI. The problem appears not to be in the mpiAPI but in
the wrapperAPI based on the ability for the mpiAPI to successfully
perform socket communications with other applications. A possible work-
around that is being considered is to reverse which API act as server
and which acts as client.A problem with the mpiAPI confusing log messages associated with the
wrapperAPI with its own internal log messages is being fixed. This did
not show up until the partial communications between the two APIs was
established to test the code.All of the dataConditionAPI Mock-Data-Challenge tests have now been
cleaned up and brought in line with the documentation. This resulted
in about a 60 percent reduction in the number of tests being performed.
Two of the tests are now failing with the whole suite of tests are run
together but pass when the tests are run individually. It is thought
that the FFTW plans are using up memory (sort of acting as a memory
leak) and reducing the available memory when the whole suite of test
scripts are run together. The results from the running of these test
scripts are now being verified.
Hardware Systems (Anderson)
no report this week
Charlton:Data Analysis Activities
* As reported in the meeting this morning, this week worked on statistics
of the FCT in bins near the chirp bin. Have looked at the distribution
of sqrt(SNR) for a chirp + noise where the chirp is fixed but new Gaussian
noise is chosen for each trial. SNR in each bin by dividing the power
of
the FCT'd sequence in the bin by the pre-calculated noise floor in
the bin
(in an earlier report I described how the noise floor is calculated).
In the bin where the chirp should be concentrated the
sqrt(SNR) distribution can be fitted to a Ricean - I need to work out
exactly what the expected parameters should be based on the chirp and
noise distribution, and verify that the observed and expected are the
same.
The other bins looked at were 1 bin away in each direction:
*
* *
* (chirp bin)
*
*
* *
The bins immediately to the left and right of the chirp bin should have
little or no power from the chirp and so should be Rayleigh, which
they
appear to be. The bins above and below are Ricean with a smaller
noncentrality as we would expect.
Lazzarini:
Tom P. and I have had a number of discussions on how the Fast Chirp Transform approach to matched filtering might be incorporated into a hierarchical search strategy. Basically this involves figuring out how to coarsen the resolution along each of the axes of the multidimensional fft produced by the FCT. The straightforward approach of adding adjacent bins in the parameter space conjugate to the measurement parameter (e.g., freq. for time) does not really buy us anything since the full resolution fft is required. I have come up with an efficient way of doing this in 1d case, but extending it to nD is not obvious .... we are still working on the issue.
Shawhan:
Continued organizing the "LIGOtools" software distribution scheme,
setting up the web pages, and installing the software at Caltech
and LHO. LIGOtools will be made available to the rest of the
LSC
soon, after a few more administrative details are worked out.
MIT:
Working on getting things setup for the ILOG system. Having some problems
with
the new disk drive.
Livingston:
(Tom E. & Shannon R.)
-We are working on the installation of our tape robot, and
trying to put it on a machine where it can be reached from
either the GC or CDS network.
-We have received the parts for our upgrade of the web and
e-mail server, and are installing them and preparing for
the change.
-We are working on preparations for the conference which
will be here in two weeks.
-We are setting up a new workstation and modeling software
for a new engineer.
Hanford:
Nothing to report.
CIT:
(Lisa)
-Swapped out Bill Tyler's 90mhz pc for something a little better.
-Working with Barbara on building an NT server to replace Antares.
-After trying multiple cards, we finally got an sbus nic that would
work in
Luna. Luna is now a gateway on the 115, 113, and 125 subnets.
This solves the
problems of epics broadcast channels on all subnets. Kater is
now officially
decommissioned.
-Replaced Janeen Romie's 2 external hard drives with 1 large one.
I also
completely re-worked her sun pc card setup. In order to install office
2000 on
the pc card, you have to have the ver. 1.3 drivers installed.
Also, the office
2000 cd is not written in a sun-compatible format. You have to
mount the cd on
a pc and share it out then do a network install.
-The new HP color scanner in the DCC had a bad Thanksgiving.
I'm still working
with HP to figure out why.
-Built a PC for a new guy.
-Replaced Cindy's hard disk. What's up with all the PCs this
week anyway?
(Samantha)
-Working on school work and getting ready for finals.
(Barbara)
- Set up the DCC software on the new server for Linda to test.
Have yet to
move TimeTarget and the "cron" jobs. TimeTarget has a new licensing
step
and I'll have to contact the author.
- Polished up the searchable web roster and moved it to the public
server
for review and testing.
- Made some changes to the LDAS Equipment database and web forms for
Albert.
- Made a number of web site changes -- meetings, fellowships, accounts,
etc.
- Recovered Antares server from some mysterious outage on the Wednesday
before Thanksgiving. Helped Cleveland with several network
errors that
hang the DCC server.
(Suresh)
-Installed older revision of firmware (NMM 4.3.0) in ES 3810 workgroup
switch
which resolved ATM uplink connection problem. The existing Rev. B ATM
module
could not support the new switch firmware NMM 5.2.2. Tests will be
conducted by
connecting more ports with hosts to see the performance with respect
to volume
of traffic generated.
-Finally made HP DesignJet 1055CM Plotter (hpplotter1) working with
Autocad
R14. Plotting from Sun workstations to this has no problem whatsoever.
Now it's
moved up to second floor and is on the production mode. The old plotter
have
been moved to Wilson House.
-Rebooted all LIGO servers except few on last saturday.
-Created another Permanent Virtual Circuit (PVC) to CACR on ATM switch.
-Work with Larry to resolve some network glitches in Bridge third floor
network boxes.
-Created a new user account.
(Larry)
-Worked a number of procurements. Mostly SUN issues. Purchased a few
items
(mostly disk drives) needed to get different computers back up and
running.
Running down a lot of paperwork.
-Worked on the setups of the new Plotter with Suresh, Ken M. and others.
-Working a number of modifications for disk configurations.
-Received a new color printer for the DCC. It will handle B-size prints
but any
printing on it will have to go through the DCC since the unit will
be dedicated
for their use.
-We had a few computers that were broken into and have fixed those
problems but
now we are checking other computers to make sure the holes have been
plugged.
These were computers being used in labs that had the problems and in
the past
we've left them alone so the users could do whatever they needed on
them but we
will have to change the builds of those units to make them more secure.
From: Phil Willems <willems@ligo.caltech.edu>
Fused silica fiber research
---------------------------
Assembled mounting hardware, electrostatic actuation, and optical
readout for violin mode quality factor measurements; all seem to work
okay. Have begun welding together monolithic fused silica double
suspension for violin mode tests. (Virginio Sannibale, Phil Willems)
Silicate bonding research
-------------------------
Built finite-element model of silicate-bonded ear attachment in ANSYS
and calculated stress distribution, showing large stress enhancement
at
edges, where bonds tend to fail. Developed code to translate
stress
distribution model predictions into polariscope image predictions for
comparison to experiment. (Frederic Seve)
From Bill Kells:
With the paper summarizing the results Jordan and I have prepared on birefringence effects in Sapphire mirrored cavities in final prep, there came up several final questions of interpretation. That is, for a given intrinsic HR coating birefringence, what would be the ultimate effect on a LIGO like ifo ? Turns out not so simple a question. So this got thrashed out
Also continues work (with some simulations) of the effect on LIGO-II performance of distortions (eg thermal lensing) and mismatch. The focus is on how the Carrier is effected (the SB effect being previously well known). Have already reported on one facit of this. Now into the remainder.
Keeping the FFT vs MELODY investigations going. Again there is slow but significant progress in this. We are getting some nice, meaningfull results, heading for a visit by R. Beausoleil early in 2001.
From Jay Heefner:
40 M and LASTI
===============================
- Sun Ultra 60 ordered for 40 M and LASTI FrameBuilders.
From Peter King:
LIGO II PSL
I have been working with Benno Willke on the
LIGO II PSL schedule
and costing. Trying to marry up the schedule
that Benno presented at the
recent meeting with Laser Zentrum Hannover (LZH)
and the one that I have
been working on for the proposal. The costing
is near completion as
currently I'm awaiting a quotation for pump diodes,
pump diode power
supplies and delivery fibers. By far and away,
the big ticket item are the
pump diodes and their associated long lead time.
From: GariLynn Billingsley <Billingsley_G@ligo.caltech.edu>
Another attempt was made to measure the homogeneity of the large Sapphire piece. I'm not yet convinced that the data are correct, and so will apply another approach before I draw any conclusions.
A piece of low water fused silica arrived from the Corning glass works. This will be sent to Stanford for absorption testing.
CSIRO reports that they have good control over the radius of curvature
of the sapphire blank that they are polishing. A spot check (mid-process)
of the microroughness indicates that they are at about 0.2 nm. This
is for the side one polishing. We have yet to negotiate a compensating
polish on side 2.
From: Virginio Sannibale <vsanni@ligo.caltech.edu>
Riccardo Akiteru Szabi
working on the earthquake safety structures
for the SAS towers. Big tower bolted down as Art (the
Caltech safety officer ) suggested. He Suggested also
to bolt down the cabinets to the floor.
Frederique
Drawings for the measurement of the quality factors
of monolithic sapphire resonators finished.
Working on the Creep Measure Facility. New 32 channels
Acquisition board the under test. Thermostabilization box of
the electronics almost ready.
Virginio
Submitted to the LIGO Editorial Board the paper: Performance
of the First Prototype of Geometric Anti-spring Filter for
Seismic Attenuation.
Made some noise measurements of the ADC and DAC boards;
very preliminary results shows ( oversampling factor of 20
and a sampling frequency of 10kHz) a S/N ration of about 124dB
for the ADC's @ low frequency.
Found several peaks above 50Hz on the spectrum, higher than
expected.
Starting analyzing data of the inertial damping of the preliminary
tests made with the Virgo accelerometers.
Riccardo Akiteru
Working in Lucca, Italy on the assembling and tunning of
the TAMA-SAS towers.
For additional information about this report, contact sanders@ligo.caltech.edu