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The LIGO Executive Committee Agenda for Monday March 24, 2003 will be:
(Meeting time: 10:30 am Pacific Time)
STAFFING COMMITTEE MEETING
NSF APPOINTS MARK COLES TO NEW POSITION
OF DEPUTY DIRECTOR FOR LARGE FACILITY PROJECTS, OFFICE OF BUDGET, FINANCE
AND AWARD MANAGEMENT EFFECTIVE JUNE 9.. WE APPLAUD MARK'S NEW ROLE AND
WISH HIM WELL!
LSC MEETING TALKS ARE APPEARING ON THE WEB.
No site teleconference or executive committee meeting was scheduled this week due to the LSC meeting.
The list of current actions
revised to reflect the status of open actions assigned through March 13,
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
Concentrated mainly on processing documents from the LSC meeting this week at Livingston.
DCC Activity
| WE 03/20/03 | Packages | Faxes |
| In | 29 | 29 |
| Out | 19 | 35 |
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)
CONSTRUCTION:
SUPPORT (Baldon, Lloyd, Tischler)
>Irene Baldon
Progress Period from 03.07 to 03.20
Out of the office the 14th, 17th, and 18th.
Completed the setup of upgraded workstation.
Weekly Advanced LIGO Project Controls meetings were not held this week.
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.
We are starting work on the Quarterly Progress Report
for the Construction Cooperative Agreement. The fiscal quarter for
this cooperative agreement ended at the end of February. Irena has
taken the lead for assembling as much material as she can from the weekly
status reports. Some additional input may be required. Since
this is the second to last report, we do not plan to make it too complicated
(basically everything is done except for buying some computer and detector
equipment).
Change Request CR-030002 to adjust
the FY 2003 operating budgets to reflect actual staffing during the first
quarter has been prepared. We will update this request at the end
of March to reflect a full six months of expenditures. Meanwhile,
we are reviewing the costs anticipated for the remainder of the Construction
Project (before June 30, 2003), and Change Requests will be prepared to
close out the Cooperative Agreement.
From: Cindy Akutagawa <cindy@ligo.caltech.edu>
No report this week.
LHO weekly report (Compiled by Rick Savage)
It has been pretty quiet in the control room this week with a large
fraction of the scientific staff attending the LSC meeting at LLO.
H1 has been locking exceptionally well all week with an 83% duty cycle
in science mode. The inspiral range was typically very steady at
just above 300 kpc. About 80% of the lock losses have been attributed
to seismic transients localized near the LVEA that typically take out both
interferometers. (details: http://blue.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=03/19/2003&anchor_to_scroll_to=2003:03:19:19:39:32-justing).
Suspecting that the source might be the LN2 tanks as was the case for the
MidX transients during S1, John Worden and Kyle Ryan have changed the torque
values for the hold-down bolts and we are waiting to see if it makes a
difference. There have been a number of quite windy periods, but
the ifos. have ridden them out pretty well.
The week started with H2 not locking in science mode for several days.
After lots of hard work by the operators, the problems were eventually
traced to a faulty fiber transmitter that was patched by Richard M. on
Monday (see http://blue.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=03/17/2003&anchor_to_scroll_to=2003:03:17:14:22:59-richardm).
Shortly after that H2 was back on line and has been locking well
with an inspiral range that varies between about 150 and 300 kpc.
The overall duty cycle in science mode for the week was 36%.
Bill Kells took advantage of ifo. down time to complete a number of
investigations including 4k SPOB drift (details: http://blue.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=03/18/2003&anchor_to_scroll_to=2003:03:18:22:57:34-BillK)
and 2k PRM cavity offset study (details: http://blue.ligo-wa.caltech.edu/ilog/pub/ilog.cgi?group=detector&date_to_view=03/17/2003&anchor_to_scroll_to=2003:03:17:17:21:46-BillK).
S2: The LLO interferometer continues to operate at about 40% duty cycle in science mode. This week, the daily fraction of the time running in science mode has been generally less than this, due to a poorer than usual duty cycle at night. Some of this may be due to the high micro-seismic activity seen some nights, however many of the loss of lock periods are presently unexplained and are being investigated.
Other: Mark Coles will be departing the LIGO Livingston Observatory to assume a new position as Deputy Director, Large Facility Projects, Office of Budget, Finance and Award Management at the NSF effective June 9, 2003.
Because of the LSC meeting also held at LLO this week, a fuller description of the week's activities will be provided in next week's report.
Details on how to connect to the teleconference will be sent in advance of the review.
Pointers to technical review documentation will also be sent out in advance of the review.
- The post-S2 version of LSC is done for now. The
DAQ portion was added
and checked against our DAQ system. We are now running
integrated
testing with our 40m lab system. Just waiting for
final word from Peter
and Daniel if ASI correction will be needed for all
AS photodiodes.
- Continued work on 40m DSC using PC/VME. We found
that through some
jumper settings, we could put our older 33MHz network
cards into the new
multi-CPU PC PCIX slots. In initial testing, we are
now able to run the
code for 8 optics on this dual CPU box with a code
cycle time of 50usec.
So, it looks like we will be able to run all 8 of
the 40m lab vertex
optics with one PC and one VME crate. The next week
or two will be spent
on the final code elements, diagnostics and further
testing prior to
installation.
- Work on digital I/O Wfs continues. The VME side
is up and running. The
PC side and EPICS code should be ready to start testing in a few days.
1. Flavio released his final electronics for
the ISS for review and is awaiting comments
2. Finished shopping for RFI antennas and received
all quotes needed. By consensus, we decided on a shopping list and
I have ordered the stuff. I am having it initially delivered to CIT
so I can check it out, and then I will ship it to the sites and probably
go there for the initial site survey.
3. Finished all known changes to the RFPD and
am awaiting a decision on the remaining few items that might alter the
design.
4. Flavio is testing the MC pole addition to the ISS electronics to verify there are no dynamic range issues with this configuration. Preliminary data does not show any problems, but we want to be sure before committing to copper.
Jay Heefner reporting
Digital Mode Cleaner Alignment Controls: A draft of
a proposed design should be ready for comment by next week.
Freq Devices DAC: In an attempt to speed up development
and testing of the DAC module, we have loaned Freq Devices a VME
processor. They will return it when their processor is delivered.
LOS Coil DAQ Whitening Board: The design of the board
is >75% complete. The final design is contingent upon the technical review
board approving a deviation from the original requirements. It has been
requested that the number of gain selections be reduced from 7 to 4 in
6dB steps.
Sander Liu
Received, repaired, re-tested and re-shipped one micro-seismic
remote interface box to LASTI.
Working on the development of a generic shielded metallic module for the new HEPI main amplifiers and post processors.
Mark has made a recommendation on the earthquake stop design to Doug, who will prototype it asap. Mark will test it as soon as he receives it. Doug received costing for the LIGO-recipe-Viton o-rings and bumpers that will be needed for the earthquake stop design Mark is testing. They are quite pricey but the vacuum-qualified Viton is the better bet for material so close to the optics. Doug also completed the drawings for the stop design. I've updated the earthquake stop design requirements document.
A revised schedule was prepared for obtaining coated samples of various mirror polishing processes on aluminum, evaluating the samples, and producing the production baffles. Aluminum sample plates have been sent to a electro-polisher and to a chemical polisher. Coated samples are expected to be available for evaluation on 4/7. Detailed layout drawings of the baffles are in process.
Ken Mailand
The goal is to mount a rectangular sheet aluminum
part to the table in front of the SOS and LOS structure to protect the
suspension wires from the errant beams.
Baffle: material, process and coating tests:
Starting material is a #8 mirror polished .12" thick
sheet and is available from ALCOA.
The #8 mirror finish is good but allows for some fine
brush marks this is the best stock material available.
The #8 finish may be improved by electropolishing
or a chemical Brite Dip process, there is a 4 day turnaround for this test.
If this process does not improve the finish we can
use the material 'as is' with the #8 polish.
Test samples have been sent to vendors, expect them
back early next week.
Sample of coating for evaluation from one of two vendors
who have the capability to do the large format we have. The two vendors
are Newport Thin Film and Reynard Corp. both in the area.
Their cost and time quotes should be in tomorrow.
Reynard Corp. thinks an AR coating is not necessary due to the effectiveness
of their absorptive coating. The selected coater will have our test materials
next week.
Baffle: Actual
The shear cut stock baffle rectangles will be laser
cut to produce adjustment slots at the base and the beam holes, ordinary
machining would be difficult re. the possibly of scratching the surface.
This material should be ready for coating approximately
5-7 days after the sample coating evaluation is complete, based on the
lead times from vendors.
Depending on the results of the polish test sample,
the polish step may not be done to the actual baffles. If the polishing
process in not done the schedule will be reduced by ~7-9 days.
The detail drawings for the baffles and foot mount
will be complete this week.
Schedule:
The schedule has some unknowns due to the vendors
operations being serial
and various start lead times from to '2-7 days' after
receipt of materials.
The longest vendor time window is the coater.
The schedule represents the lead times and process
times by the vendors best estimate.
The parts count is: 11 SOS baffles, 3 LOS baffles,
3 IO baffles [2 parts ea.] 4 RM beam
Dump glass replacements, and a foot mount for each baffle. Sizes are 7" x 18.5" for the SOS and 16.5" x 28.5 " for the LOS
The quotation for an extra set of optically contacted
pre-modecleaners
was received. This will result in spare pre-modecleaners
for each
interferometer.
I've have been looking into which
larger water chiller to purchase for
increasing the cooling capacity for the laser.
In addition, it is worth
noting that the current refrigerated bath is no longer
a current product.
Late last week, Rich and I did a preliminary measurement
of the beam jitter
out of the laser. I was surprised at just how
sensitive the quad
photodetector was with some 50 microns per 960 mV.
I haven't had time to
think about the measurement much but hope to repeat
it. But initially we
did not see much correlation between the beam jitter
at low frequencies and
the performance of the intensity servo.
OTF Lab. (W. Bridge)
Contamination Cavity # 1
The test sample. CHEM-SOL Hydraulic fluid still under vacuum for one
more week.
We are taking ring down and beat frequency measurements everyday and
so far we can tell
that there is no contamination.
Please see Dr. Zhang graphs for absorption, ring down and thermal lensing.
Absorption Test Measurement prototype is in STANDBY.
Scatterometer
The function of the scatterometer has been fully recovered as mentioned
before.
We have removed the existing ETM from the scatterometer base holder
and replaced with the
dummy one to find the exact center of the ETM.
I have machined some parts to fit an iris ring and adopted to the dummy
piece. Now we can direct
the laser beam on center of the ETM easily.
Adapting the new larger mirrors and mounts on the scatterometer optical
train
in order to catch the AR reflected beam is in progress.
We got a new High performance GPIB interface card for a PC windows.
This will allow us to
measure ring down. This card will be installed in the existing PC.
(We need to update the PC)
OTF Lab at Lauritsen ROOM 38
Cavity #3
The test sample from Leander Lubricants
CHEM DRAW’ # HSF-75-2, Batch 12302001. (a synthetic, hydraulic fluid.)
with different additives is completed. We concluded that there
is no contamination.
Please see Mr. Zhang's latest graphs for absorption, ringdown and cavity
thermal lensing measurements.
We have introduced a new sample from Chem-Sol, Inc. SR FR HF this
is an Undyed Fire retardant
Hydraulic Fluid. This sample is being pumping down and laser
alignment is in progress.
Cavity #2 Test cavity
The chamber is pumping with new cleaned mirrors ~ 70ppm each.
RGA measurements, optical train set-up still in progress as we waiting
for new optical
mounts and mirrors.
The new contamination chamber is completed but we are making a decision
as to buy new
view port windows or used the existing windows from the other chamber.
It is on hold.
Finally, I have received the Kapton (Polyimid) paint sample from Ricardo's
group. This sample
will go in next in one of the chambers.
no report
no report
LASTI Weekly
MEPI (Dave O,Rich M,Dennis C, Myron M, Gregg H)
This week we achieved two important milestones in MEPI work. The full
7-axis control with sensor blending and sensor correction was achieved.
Reductions in the 1.6 Hz beamline mode of about 20 were observed. Some
of the problematic higher mode ~50 Hz have been traced to the rocking of
the baseplate. The shims were replaced in one pier with solid 18 by 4 inch
shimstock and the transfer fuction was significantly improved.
HEPI (Corwin H, Dennis C, Rich M)
THe actuator with the fluttering valve on horizontal pier 3 was replaced
in situ. The procedure went flawlessly with no fluid contamination
and the actuator works fine. Reasons for isolation being less in the Y
direction continue to be explored.
Simulation and Modeling (Hiro)
LSC Meeting
Matt Evans presented a talk about e2e about
(1) the lock acquisition, including the discussion
about the effect of
the thermal lensing and mode mismatching. A caveat
about the difficulty
of locking using the current error signal sets
was pointed out when the
system is close to mode matched.
(2) the simulated sensitivity curve, with as built parameters and
realistic ASL/ISC/DSC. The simulated best performance was very close
to
the SRD curve, except for the lower < 100Hz, where the performance
is
worse by factor of 2. Part of this is a known result, published before
in E960112-05-D by DHS.
Radiation Pressure
Hiro, Malik, Matt and Vijay discussed about the effect of radiation
pressure noise and implementation in e2e. Toward that effort, Hiro
made
a simple MC box for Malik and Vijay start playing with it. Vijay is
assigned to gather information about LSC/ASC, and Hiro is to build
a
primitive to support the radiation pressure effect. Sany Yoshida's
data
about HAM tables and LLO seismic motions will be used for it.
Simulation code development
Matt found that the mirror motion is inducing unphysical noise due to
the numerical accuracy, i.e., stack+pendulum ~ f^-7 is too speed to
be
handled by double precision. Hiro modified the 3d mirror primitive
to
cure this issue by using quadruple precision in this module.
Modod finished some optimizations the modeler's functions analyzer.
She
is currently doing some benchmark timings for different scenarios.
She also started working on a new if-then-else construct for the
modeler.
Alfi5
Bruce worked on automating the connection trim execution for cleaning
up
connections and junctions.
LIGO Data Analysis System
Software Systems (Blackburn)
Hardware Systems (Anderson)
Data Analysis Activities (Lazzarini)
Shawhan:
* Checked calculation of inspiral upper limit result.
* Reviewed pulsar upper limit paper.
* Prepared talks for LSC Meeting, and gave them.
Reilly:
I spent most of this week trying to analyze the pre-S2 hardware
injections. I went around in circles for most of the time trying
to figure out what data I needed in order for the analysis to use
of the correct calibration. I made attempts at some ad hoc calibrations
but eventually had to give up. Work is now being done by
the calibration team to generate the correct calibration factors.
Once these are ready I will finish the analysis.
General Computing (Wallace)
MIT:
(Keith)
-Finalized quotes for PC raid and sent them to Caltech
(low bidder was Aztek Computers in LA area)
-Reinstalled desktop PC for Tania
-Downloaded glibc patches for RedHat and tested installation on a spare
pc
-Continuing investigation of sfs
-Finished investigation of SSH windows server
-Purchased printer supplies
-Looking into used sun equipment as failover/backup strategy
Livingston:
(Larry for Shannon)
-Busy with the LSC meeting and related support.
Hanford:
(Christine)
-On operations shift all week.
CIT:
(Lisa)
- Built a new box with apache2/ssl to replace tegmeni.
- Swapped out Bill Kells' old ultra1 for a blade100.
- More work on the RAV spam filters.
- Restored a file from 1998 for Mark Barton.
(Veronica)
- LIGO website: posting Aspen transparencies. Posted the latest
newsletter. Several other updates to the website.
Continue working on the DCC database trying to determine what caused
the
latest glitch.
Working on Advanced LIGO website.
Working with the Digital Media Center on processing LIGO VHS tape archive.
- LSC website: set up a webpage for the March meeting talks; posting
the
talks as they arrive. Modified a backend database to allow a separate
table/query for closed-sessions talks to be output to the talks webpage.
Currently a webpage of public talks only is posted, pending a reply
from
Rai Weiss.
- CaJAGWR website: working on the video/slideshows of talks. Updated
the
website.
(Mike)
-Had to uninstall and reinstall solid works for Callum. This took me
several hours due to multiple unknown processes that were running
preventing this software from doing a clean uninstall. Then installing
this
software over again turned out to be a real pain due to downloading
multiple service packs and fighting to load the additional plug-ins.
-Ran security/OS updates on Helena Armandula's laptop and setup a dial
connection for travel.
-Ran security/OS updates on Linda's laptop and updated the ghost image
of
this laptop.
-Ran security/OS updates on Florence Kaufman, Dorothy Lloyd's computer.
-Ran security/OS updates and updated software on the second floor of
West
Bridge, which consisted of eight computers.
-Tried upgrading Paul R.'s computer from win98 to win2000, but this
unit failed
due to hardware problems. I did manage to get a ghost image of his
computer
& update some of the General Computing software that was way out
of date.
-Had to reload the Millikan conference room PC due to the boot commander
getting
corrupted. This is back up in the conference room.
-Updated servers with a vulnerability patch that involved an IIS-5
security hole and added some extra security features to all servers.
-Lisa and I shuffled some equipment and surplussed some older equipment.
(Larry)
-Worked through a number of procurement issues. In the process of ordering
a
number of items including PC's, printers, supplies and updating maintenance
contracts.
-Resolved a security issue. One of the WEB servers had been compromised.
We are
still going through the machine to discover exactly what had happened
but most
of the log files were deleted and other markers were removed. The unit
was
performing a DOS attack and it appears that it was launched from a
hole in the
apache s/w.
-Had Cleveland return the Foundry hardware. It took some time to get
the correct
instructions for returning the units but they finally came through.
-Working on a couple of reports. One of them will be a report on the
Computer
Security conference I attended last week. This should be of interest,
one thing
they gave us a set of questions people should ask their bank if they
plan on
doing on-line banking. It was a surprise on how easy it was to get
control of
another persons bank account when things are not setup correctly.
-Spent a deal of time working a number of different DCC items.
-Removed a few accounts and cleaned up a couple of others.
-Working with Keith on resolving a computer connection problem with
a LDAS box.
So far we have been able to rule out most of the network boxes.
-The e-mail filtering s/w has been catching a large number of spam
and porno
related e-mail. The subject filter has been setup to filter a number
of obscene
words plus a number related items. The filtering will not capture all
of the
junk/spam e-mail being sent but a significant amount is being blocked.
Presently, we are keeping an eye on things to check for false positives
and so
far we have had very few.
Seismic Isolation
Nothing to report.
Suspension
From: Janeen Romie <romie_j@ligo.caltech.edu>
AdLIGO Suspensions
I've been working with Larry and Dennis on the optical layout, going
over Dennis' proposed changes.
This morning, Calum hosted a meeting with Mike P-L, Mike Plissi, Russell Jones and myself to look at what still needs to be done on the MC and RM suspensions along with other suspension tasks. It was an organized and constructive meeting. Mike P-L has progressed rapidly on the RM design. Russell Jones reported that the machine shop is reworking the stainless hybrid osem heads and starting to fabricate the aluminum heads.
We will have a meeting next week to discuss our proposed schedule for quad modeling and design to support the seismic group.
PEEK: LIGO has vacuum qualified PEEK connectors that are manufactured by Accu-Glass. Chuck McIntyre from Accu-Glass reports that they only use natural PEEK, conforming to ASTM-D-6262, Type 1, Class 1, Grade 1. They buy the material in sheet form and machine it . They use machining fluids that are water soluable and free of sulfur, chlorine and silicone. Calum and I have copies of the ASTM spec., if anyone is interested.
Gin Gin Suspensions
I'm progressing on the ETM design. Helena has completed the ITM assembly
document. I accidentally broke off some magnets on the ITM, which I re-glued
this morning. She and I will rehang it Friday morning.
From: ctorrie <ctorrie@ligo.caltech.edu>
ADVANCED LIGO SUSPENSIONS
MC and RM
Janeen, Mike and I met Mike Plissi & Russell Jones to discuss the MC and RM suspensions. This was an attempt to appoint people to the various tasks and to priorities the various tasks. Several of the outstanding tasks including the modelling of the blades and the design of a catcher will be very useful in helping us model more detail for the proposed quad suspension.
Mike Perreur Lloyd has completed his 2nd spell at Caltech. During his
visit he completed the assembly of the parts for the RM suspension. As
a result Ric Paniagua has started production of the RM suspension parts.
The next stages include the design of the catchers, the wire jigs and
the parts associated with the structure. Mike Lloyd will continue to help
with this work from Glasgow.
Please see Janeen's report on an update on the Glasgow work related
to the hybrid OSEMs.
ANSYS
Mike Lloyd and I have been working on several of the on-line tutorials
that are available with the software. We also have a tutorial from one
of the PhD. students in Glasgow, which we hope to distribute once we get
the final draft. Technical support is only available using the following
e-mail address: - techsupp@ansys.com. I have used the support and they
have replied usually within the hour.
From: Jay Heefner <jay@ligo.caltech.edu>
Gin Gin Suspensions
========================
- The controller and satellite amp for the first optic is operational
in the 40 meter south annex. The other two controllers appear to have been
damaged when shipped from LHO. They should be repaired and ready by early
next week.
From: Michael Smith <smith@ligo.caltech.edu>
ADVANCED LIGO
An analysis of the thermal noise coupled from the PO mirror onto the SEI platform in the Adv. LIGO BSC chamber was completed. The analysis indicates that a relatively weak support structure--resonant frequency of 30 Hz--would not contribute excessive thermal noise to the SEI platform. However, Dennis has pointed out that the control dynamics of the multi-pendulum SUS will require that the PO mirror structure have a resonant frequency > 150 Hz. This requirement will likely necessitate that the PO mirror be a suspended structure; likewise, the ETM telescope will probably have to be a suspended structure.
Prestabilized Laser
From: Peter King <pking@ligo.caltech.edu>
AdvLIGO PSL
===========
The preliminary AdvLIGO PSL
technology downselect was made.
Unfortunately - or fortunately - there was no
clear cut choice from the
standard performance tests. If my recollection
is correct, the default
decision is to pursue the LZH rod program as
a foundation for the PSL
conceptual design. Development of the other
two laser technologies, namely
the stable/unstable oscillator and amplifier
approach, would still continue.
[GHS note: Peter's memory is correct]
Input Optics
From: David Reitze <reitze@phys.ufl.edu>
- high power rubidium tantanyl phosphate (RTP) electro-optic modulator*
- constructed and tested
prototype modulator
- temperature-stabilization
loop
- medium-term (100 hr) exposure
at Advanced LIGO power
densities; no problems so
far
- prototype Faraday isolator
- thermal birefringence
compensated FI units (> 40 dB) from IAP
delivered to LZH and Adelaide
- thermal lensing compensation
using negative temperature
derivative FK51 Schott glass
- absorption measurements to match TGG and FK51 for
each individual FI; FK51 cut to length and polished
- integrated lensing and
birefringence FI prototype undergoing
testing at UF
- adaptive MMT for Advanced LIGO
- no moving parts; in vacuo
adjustment**
- modeling indicates large
adjustment range with no modal
contamination
- prototype table-top being
tested at UF
Core Optics
A lot of activity around coatings at the LSC meeting, in particular concerning the thermoelastic noise from coatings.
Auxiliary Optics
Nothing to report
Interferometer Sensing and Controls
Analysis (Buonanno, Chen, Mavalvala -- gr-qc/0302041 -- and subsequent discussion at the LSC meeting makes it clear that the DC readout option is preferable for the sensitivity it can deliver and the simplicity of the technical approach.
Data Acquisition, Diagnostics, Network & Supervisory Control
Nothing to report
Other Laboratory R&D
From: Riccardo DeSalvo <desalvo@ligo.caltech.edu>
Allyson
Confirmed B14 hardness split into two classes
Re-indenting missing samples to fill gaps in hardness plot.
Stefano
Tried several brazes (Au71Sn29)Tix with x up to 4% atomic (13%
w.)
At high Ti concentrations it wets very well but it does not stick much
more, nowhere close to S-bond (AgSnTi).
In stress strain tests the MoRuB sample slipped off cleanly from in
between the sandwitch surfaces at 22 Kg stress.
Tried AuSnTiNi with similar results.
Tried different concentrations of Sn and Ti in AgSnTi. Probably
the commercial composition is close to optimal, may be better with some
more Ti.
In stress strain tests with S-bond both the MoRuB and CuBe surfaces
remained wet, but the braze cracked at the braze to braze surface showing
significant impurity deposits. Need to improve cleanliness with S-bond.
Eric
Molten MoRuB18 and other alloys.
X-ray scattering tests on last week alloys. Not slow cooling
rate vitrification observed.
For additional information about this report, contact sanders@ligo.caltech.edu