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The LIGO Executive Committee
Agenda for Monday May 22, 2000 will be:
(Meeting time: 10:30 am Pacific Time)
Open meeting 10:30 - 11:30
Special Items:
Mode cleaner and PAM magnets at LLO
No report.
WBS 1.2 LIGO Operations--Administration
From: Ed Chargois <chargois_e@ligo.caltech.edu>
Assisted the LIGO Livingston Facility Manager (G. Stapfer) with a short term lease of a GSA vehicle (Oldsmobile) with several more vehicles to follow within the next two weeks.
Assisted the Seismic Attenuation Group (R. DeSalvo) with the preparation of a Commercial Invoice, U.S. Customs Declaration and transportation of the Monolithie Geometric Anti-Spring Filter to Galli & Morelli (Carlo Galli) of Acquacalda (Lucca) Italy. Account Number: LIGO.00002-3-NSFLIGO.504800.
Assisted the Seismic Attenuation Group (V. Sannibale) with the preparation of a Letter of Authorization to transport through U.S. Customs to Italy a VME/VSB VBeX ADC816C Data Acquisition Board Serial Number 06. Account Number P157718.
Assisting the Caltech Property Accounting Division with Support Documentation concerning the Class Action Settlement of all perviously purchased or leased Toshiba Laptop Computers.
Submitted disposition documentation (Standard From 120) to the National Science Foundation to dispose of the excess property located at the LIGO Hanford Observatory.
| Packages | Faxes | |
| In | 32 | 35 |
| Out | 15 | 47 |
Special Projects: Electronic Docs! Electronic Docs! Electronic Docs! Need I say more?
From: Esther Cunningham <esther@ligo.caltech.edu>
Press here for ACCOUNTS PAYABLE HISTORY DATA.
From: "Brambila, Ruth" <Ruth.Brambila@caltech.edu>
http://docuserv.ligo.caltech.edu/docuserv/home/accts_ops.pdf
http://docuserv.ligo.caltech.edu/docuserv/home/accts_adv.pdf
Discussions are ongoing between Caltech and Demco to resolve the issue of Demco accepting P-cards for payment of electric bills. At issue is the 2% surcharge added by the credit card company. A backup plan is to use wire transfers to make the payments.
No report this week.
Progress Period from 5.12 to 5.18
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 |
Press for the latest Contingency Needs Projection.
From: Kris Duncan <kris@ligo.caltech.edu>
No report this week.
Announcements:
--------------
(F. Raab)
The completion of LIGO-I seismic isolation
was celebrated this week at the Rattlesnake Mountain Brewery.
Alignment of the mode cleaner and interferometer resumed the following
day. COS installation work is ongoing. Currently, a split shift crew is
working on measuring reflectivities and transmissions for the 2K recycling
mirror, which requires the LVEA to be cleared of other activities.
Last Friday night, there was a "Science Night" held at Gladstone High
School in Oregon, where ~30 students gave presentations to parents and
community members on their projects as part of the LIGO Scientist, Student,
Teacher program.
We continue to have increasing requests for tours of LIGO (>100 visitors
this week).
Bake Oven:
----------
(K. Ryan)
Vacuum Bake Oven A load #90, consisting of Arm Cavity Baffle parts,
was released on 5-8-00.
These were Allied Engineering parts that were not cleaned onsite.
This load required rebaking.
Load #91, consisting of Arm Cavity Baffle parts, was released on 5-12-00.
These were Allied
Engineering parts that Bartie recleaned onsite and did not require
a rebake.
Load #92, consisting of Arm Cavity Baffle parts and reworked "H" tubes,
was released on 5-16-00. These were Allied Engineering parts that
Bartie recleaned onsite and did not require a rebake.
Load #93, consisting of 4K Pick Off Mirrors, Steering Mirrors and Temporary
Optical Lever Mirror Spacers, was released on 5-18-00. This load
was approved for an early release and did not complete it's scheduled bake
as a heater blanket failed and could not be repaired in situ.
I have been given the OK to acquire a second, smaller, vacuum bake oven,
heretofore referred to as "Vacuum Bake Oven B".
Mode cleaner commissioning: We have continued to investigate why we see more angular motion in the LLO mode cleaner output than at Hanford. We have seen that the problem lies in the mixing of pitch and yaw modes, but also longitudinal and side pendulum modes. This arises from the presence of the PAM magnets that introduce new non-orthogonal forces to the mirror motion. This was verified by setting up a test mode cleaner suspension and measuring the effects of moving the PAM magnets close to the mirror.We will continue to investigate the effect of LLO seismic noise on the mirror motion and then perform measurements that must be completed before the vent in early June. (Joe Kovalik)
Mode matching calculations: (Sany Yoshida): I calculated the
locations of mode matching lenses on the PSL to give the best
mode matching to the MC. The calculation indicates that when the mode
matching lenses are placed at the following locations, the best mode matching
is obtained.
Best locations:
z1 z2 z3
zMC w0
110" 12" 30"
12.5 m 1.62 mm
where
z1 = EOM waist (center of 2nd EOM) to MML1
z2 = MML1 to MML2
z3 = MML2 to MML3
zMC = EOM wasit to the waist of beam going into MC
w0 = waist size of beam going into MC (i.e., spot size at zMC)
I also calculated how much zMC and w0 change if mode matching lenses are moved, for the following cases:
(1) when MML1 only is moved
z1 z2 z3
zMC w0
112" 10" 30"
13.2 m 1.7 mm (move MML1 toward MC by 2")
108" 14" 30"
11.8 m 1.55 mm (move MML2 toward EOM by 2")
(2) when MML2 only is moved
z1 z2 z3
zMC w0
110" 14" 28"
11.5 m 1.5 mm (move MML2 toward MC by 2")
110" 10" 32"
13.2 m 1.76 mm (move MML2 toward EOM by 2")
(3) when MML3 only is moved
z1 z2 z3
zMC w0
110" 12" 40"
13.0 m 1.45 mm (move MML3 toward MC by 10")
110" 12" 20"
13.2 m 1.75 mm (move MML3 toward EOM by 10")
(4) when all 3 lenses are moved
z1 z2 z3
zMC w0
120" 12" 30"
12.2 m 1.20 mm (move MML1-3 toward MC by 10")
100" 12" 30"
10.0 m 2.02 mm (move MML1-3 toward EOM by 10")
I am planning to improve the mode matching by relocating the lenses
based
on this calculation.
Test influence of PAM magnets to SOS (Sany Yoshida): We set up a spare
SOS in optics lab and investigated the influence of the
PAM magnets to the small optics's motion. We measured power spectrum
of OSEM photo detectors and an optical lever. We also shook the optical
table by a shaker and measured the transfer function of the shaker input
to the optical lever signal. We found that insertion of the PAM magnets
change peak frequencies of pitch and yaw (the new frequencies correspond
to combination of pitch and yaw). For further details of these measurement,
see Tom Nash's LLO E-log entry on May 16 and S. Yoshida's entry on May
12)
GDS: (Szabi Marka): Installed fiberoptic cable from mass storage room
to computer users room. Installed PacketEngines FDR 12 gigabit repeater.
Installed gigabit net/card/software on GC machine in computer users
room.
OPTICS: Cleaning and baking of COS components continues. Several hands-on demonstrations for our student outreach display are being assembled as time permits.
Last weekend, we suffered a major contamination incident. Visitors and staff alike, working in both the vacuum prep and optics laboratories introduced contaminated material which elevated particle counts in the laboratories to > 12,000. Aggravating the elevated particle counts, a dirty shaker and accelerometer was placed within a flow bench adjacent to a cleaned and baked SOS, contaminating it. Fortunately, 4 core-optics which were in proximity to the contaminated material were bagged and covered with aluminum containers. The weekend's activity occurred without the submission and approval of a work-permit. This setback emphasizes the need for everyone to submit a work-permit before beginning any activity in the laboratories. (Jonathan Kern)
The optics on ISCT3 are layed out and aligned. We are working on getting the polarization correct. (Anthony Rizzi)
Installation: Optical Lever Tables in LVEA were steam cleaned and oxysolved,
removed legs and rotated for proper lateral adjustment, reinstalled. Placed
both X & Y tables in proper position and dog eared down. BSC#2 Optical
Lever mounts installed. ISCT4 was received and inspected O.K., installed
legs, assembled and installed cover, placed at BSC#3 inside portable clean
room. Control Room video monitors and speakers were suspended from the
ceiling to free up table top space at the consoles. Installed clocks (pacific,
central & universal times) Ran 4 common computer lines for lap top
use. (Rich Riesen)
No report
No report
| Installation:
Livingston |
Commissioning:
Livingston |
Other
Science/Engineering
Activities |
In running the servo, the new servo seems to exhibit most of the characteristics of the old servo. Should the beam to the reference cavity be blocked and unblocked the servo re-acquires without oscillating. Something that doesn't happen with the LLO version of the same card.
As this report goes to press, a comparison is about to be made with the old servo card.
Rich Abbott
Continuing to test and work
through the rev C upgrade of the FSS that was brought back from LHO.
We have made quite a bit of headway in the test area in the basement of
Lauritson. More work is needed before we are confident enough to
ship.
The RM ghost beam beam dump
for HAM9 has been installed and aligned. The viewport beam dump on HAM9
was installed and aligned. The APS telescope baffle was installed. The
y-manifold and x-manifold arm cavity baffles were installed and aligned.
The cavity beam dumps in BSC7, BSC8 and BSC4 are in the process of being
installed and aligned.
MC reflected and transmitted beams for IOT7 table are aligned and centered to their viewports using COS viewport targets. We noticed that the height of the viewport center is 40mm lower than the standard beam height on HAM7 table. We also used a retro-reflector at FI output to mimic the reflection from the recycling cavity and aligned the FI rejected beam for ISCT7 table
MMT alignment is halfway through. We centered the beam on all SMs and MMTs. Searching for the returned beam from RM is the next.
A special (small footprint) beam block for the Faraday has been fabbed and sent to LLO for baking and installation. New SOS alignment targets have been designed which incorporate irises for more accurate beam positioning.
Issue #1 is finding out the reason for the large motion of the transmitted mode cleaner beam, of order 10 times larger than at LHO. LLO's larger seismic noise at 1 Hz may account for a factor of 3. The beam jitter at the MC input probably doesn't contribute much, because of the filtering action of the MC.
We attempted to make the diagonalization program work on these suspensions. The previous attempt had foundered because of the "non-sensical" responses of the OSEM outputs at various modes. A combination of new detailed modeling and experiments on a spare SOS suspension revealed the reason: the PAM magnets cause strong perturbations to the mirror motion, so that the true normal modes have none of the symmetry that a PAM-free suspension has. (For further details of these measurement, see Tom Nash's LLO E-log entry on May 16 and S. Yoshida's entry on May 12.) In principle one might model these modes in detail and push the diagonalization program through to completion, but the mode shapes depend sensitively on parameters that are hard to measure well, such as the depth of PAM insertion and perhaps on installation errors.
This insight also goes part of the way toward explaining why the different modes of the mirrors aren't equally well damped -- the whole modal picture that is the basis of our controller design bears little resemblance to the actual modes. Nevertheless, we found several ways to adjust the controller gains so that all modes are well damped.
We hoped that by damping all of the modes we would be able to reduce the motion of the MC beam. This worked to the extent that peaks corresponding to undamped modes can be pulled down as those modes are damped. But the dominant contribution to rms motion comes from a peak near 1 Hz that does not get reduced as the 1 Hz modes in the suspension are strongly damped. At the moment, all we can think of is that the response of the SEI stacks are not what they ought to be, and perhaps have a peak near 1 Hz. We have started to make transfer function measurements, and hope they might confirm or refute this hypothesis.
What should be the fate of the PAMs? Even though the modal problem doesn't appear to be the cause of the large beam motion, it may still be better if they could be removed. Diagonalization will be much harder (if not impossible), so reducing length-to-angle coupling will be hard to achieve. One question is whether alignment can be achieved without them. Two of the MC mirrors as hung now have large pitch errors (of order 7 and 4 mrad) that are corrected by the PAM screws. They would eat up large amounts of controller dynamic range, although perhaps they could be rehung. One recommendation is clear however: if we persevere with PAMs on the SOSes at LLO after the next opening of the vacuum (as opposed to say increasing the range of the controllers as at LHO), the spacing in the initial neutral position should be much greater than it is at present, e.g., 13 mm between PAM magnet and optic magnet faces as opposed to the current 8 mm. This still gives an adequate adjustment range of about +/-10 mrad in 4 turns of the screws, but enormously reduces the cross-coupling.
Metrology mounts from Bryan Loucks have been delivered. These will enable us to measure optics in a horizontal orientation.
Achim Leistner, who is in charge of polishing the LIGO optics at CSIRO has been awarded the David Richardson Medal by the Optical Society of America, for distinguished contributions to technical optics, including the LIGO Optics. Read more in "Optics and Photonics News" May, 2000, page 17.
Helena and I will visit General Optics on May 22. The purpose of the trip is to discuss test coating runs for R&D purposes and to discuss metrology on the 4 ETMs which GO will repolish.
Rich Abbott
LSC/ASC Frequency Distribution:
Prototyped the AM Stabilizer Daughter card and locked the amplitude of
one of the boxes used to drive the EOMs. A schematic for a real board
has been completed, and a board has been layed out. Will send this
board out on 18 May for rapid turnaround. This will allow the LHO
Frequency Dist system to set the modulation index remotely with a voltage.
Two new suppliers of beam dumps have been found. In one case the beam dump should be able to handle the laser power without getting too hot to the touch.
Lee Cardenas
Continuing the drawing for
the 40m. Lab. Enclosure. Made alignments from the sample beam from
the Laser into the Ref.Cav. Chamber. Enquire and placed order on detection
cards, Beam detector(ceramic type) for the CW ND:YAG Laser.
Made some SMA cables and arrange the cabling on the laser enclosure.
Mike Zucker
Issued RFQ and received
bids on remaining video cameras and lenses to complete chamber and ISC
table video installations both sites. Will issue PO shortly.
John Zweizig
I have been working on preparing
a new release of the dmt software and incorporating packages from LSC,
et al. I expect that I will have it ready to install by early June when
I visit LHO.
Sander Liu
Completed preliminary signal
processor schematic design. Currently working with vendors to get quotes
for long lead items.
Worked on modification to
optical lever calibration procedure to treat calibrations done when beam
is far from null (i.e., normal operation). New lookup table will
permit interpolation of "central" (nominal) sensitivity and/or inversion
of nonlinearity.
No report
Commissioning last of 4 annulus systems (BSC missing one small part
on backorder).
Rigged equipment for inner O-ring test to commence
Friday or Monday (backfill each annulus in turn
and look for air signature in main volume).
Discussed technical (noise) goals & optical
topology for test interferometer with
D. Shoemaker, P. Fritschel and others.
Simulation and Modeling
simulation code development
Matrix class was improved to speed up the Michelson cavity simulation
by factor of 2.
Suspdended 3d mirror primitive is completed, tested and documented.
RSE
Matt studied the signal characteristics of Jim's RSE configuration
in order to find a different signal for better locking.
Alfi4
alfi4 is available now. This is still beta, but looks pretty stable.
This version supports multiple directories and easy handling of
heavily nestedt boxes. Further improvements will be included in
the next release on Monday. These will make the new features
more useful.
LIGO Data Analysis System
There were two problems within LDAS software which are proving
difficult to solve this week. Threads were originally implemented
in several of the LDAS commands made available to the TCL layer.
These functions were either insufficiently tested in the distant
past or as the results of changes in compilers, OS, and code have
stopped functioning perfectly. At present, it is possible to start
several hundred threaded processes before a thread hangs. There
are non-threaded versions of these functions so not having thread
support is not critical to the existing LDAS APIs. However, the
new dataConditionAPI will definitely need working threads at a
much higher reliability than the roughly 399 out of 400 working
now. The other problem is with memory management and usage of the
widely available memory leak checking packages available. The
main memory leak is in the frameAPI. Attempts to attach three
different leak checkers has failed do to a host of differing
reasons with each tool. Some improvements in the memory management
were implemented by code reviews however, to solve the ultimate
failure of an API, the managerAPI was beefed up to support the
termination and restart of an API which exceeds a preset amount
of memory usage. In addition we were able to integrate a memory
management package (dlmalloc) which allows the APIs to use the
shared memory instead of heap for dynamic memory so that used
memory can be returned the the system.
The wrapperAPI now only needs to support for the command passing
with the mpiAPI and the internal flow control to be ready for
integration with the shared objects being developed by the LSC.
The UWM group is nearly finished with the first test shared
object and we expect to begin integration and testing the first
of June.
The remaining activity for the group was preparation of a new
procurement plan for LDAS hardware in response to the NSF review
actions. A draft for this plan should be ready by the end of the
week.
Anderson:
Placed an evaluation order for a large Ethernet switch to be tested
at
Caltech as a candidate for the main LDAS computational switch.
Proposed an integrated CACR/LIGO HPSS growth plan to triple the amount
of tape storage available to LIGO.
Additional research for the LDAS procurement plan.
General Computing
Larry has been working on a procurement of Sun equipment
for various components of LIGO Laboratory.
From: Helena Armandula <ahelena@ligo.caltech.edu>
Contacted Gary de Bell from MLD. They are preparing a quote for the
coating
of 4 silica substrates to Caltech specs.
G.O also own and operate 2 ion beam sputtering chambers. Next Monday
we'll
discuss G.O's possibility of making LIGO coatings. G.O seems
very
interested in working with us.
From: GariLynn Billingsley <Billingsley_G@ligo.caltech.edu>
Helena and I will visit General Optics on May 22. The purpose
of the trip is to discuss test coating runs for R&D purposes and to
discuss metrology on the 4 ETMs which GO will repolish.
From: Riccardo DeSalvo <desalvo@ligo.caltech.edu>
Delayed removal to upper section of Synchrotron while waiting for the
space to move in to be cleared.
Szabi, Riccardo
Tested oil bearing with 1 ton load mounted asymmetrically over three
bearings.
Designed and started production for two platforms for LIGO and TAMA
SAS
after removal; made DAQ software for thermometers and Keithley.
Alessandro
Making coils for TAMA prototypes in Pisa. Updating accelerometer
design
with EDM company, getting new batch started.
Virginio
Automatisizing MIMO diagonalization procedure, next week going to Elba
conference, there he will compare our MIMO technique with the Virgo
one.
Akiteru
TAMA suspension description first draft document. In suspension
design
will need some vertical springs for the intermediate mass wires to
control thermal noise. Considered the bellow springs used by
TAMA so
far and small MGASFs. Built a small prototype in normal spring
steel
(12 cm across, 1.2 Kg load, 500 mHz resonant frequency) that works
OK.
It seems to satisfy all requirements to suspend the 1 Kg mirror, 1
Kg
recoil mass and 2 Kg intermediate mass of the proposed suspension.
Need
to make a maraging version of it.
Hareem, Soy
Measured MGASF blades at low frequency and found low hysteresis.
The
hysteresis is strongly sex dependent. If a strong male tightens
the
screws it is much better. Tightening too much flexes the cross
beam and
is not better. This problem will go away in the first prototype
with
wedged clamps. It was not observed in the old GASFs.
Made thermal measurement of MGASF blades, the measurement was too fast
and must be remade because the thermometer on the body heats at half
the
rate than the thermometer on the blades, however measured 0.3 mm/oC
at
250 mHz.
Flavio
Marconi concept and development scheme first draft.
Riccardo
Modified elastic joint base for future IPs to eliminate a small residual
hysteresis that probably came from the same reason of the MGASFs
hysteresis.
Small MGASFs for Akiteru’s needs.
Shipped MGASF to Elba conference.
Chenyang
First draft of on actuator report.
G&M
TAMA SAS was to be ready to ship end of this week will be delayed a
couple of working days. LIGO SAS new counterweights may be a
few more
days late due to material procurement. Same for spare MGAS filter.
PROMEC
Checkout of parts to be shipped. Including last corrections from
Alessandro to accelerometer design.
From: Sam Richman <srichman@ligo.mit.edu>
Stiff isolation system (S. Richman)
The high-frequency filters in the lower stage horizontal loops were
improved, allowing a factor of 3 increase in gain. The position
sensors
signals were also rolled off better, and there is now a small band
of
coherence around 8 Hz between horizontal ground motion and lower stage
motion with all 12 loops closed. The isolation in this band is
about 45 dB
(63 dB in the vertical). We are now returning to the issue of
integration
of the broadband seismometers, to reduce the rms motion of the system.
For additional information about this report, contact sanders@ligo.caltech.edu