THE ELECTRONIC ALADDIN
NEWSLETTER NO. 12
May / June 1997
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NEXT USERS MEETING
A tentative date has been set for the SRC Users Meeting: It is planned for Friday, Oct.
17, preceding a topical workshop on correlated electron systems on Saturday Oct 18th.
Suggestions for the meeting, including the date, are welcomed. E-mail them to Franz
Himpsel(himpsel@comb.physics.wisc.edu).
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ALADDIN LAMP AWARD
This year's Aladdin Lamp Award went to Krista Mullman for her work on High Sensitivity
Absorption Spectroscopy in Ions Using UV/VUV. The award recognizes excellence in
synchrotron radiation research performed at SRC in pursuit of a degree. Krista performed
absorption spectroscopy with iron and cobalt ions at a resolving power exceeding 300,000.
They are important for determining abundances of these elements in the universe from
Hubble space telescope data. Krista will join the National Institute of Standards and
Technology (NIST) next year to work on optical tweezers.
The award was presented at a special SRC Users Meeting that took place on the occasion of
the re-dedication of the SRC building in honor of Ednor M. Rowe on May 3. About 120
visitors from near and far took part in the re-dedication ceremony.
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SPACE TELESCOPE DETECTORS BEING
CALIBRATED AT SRC
Several groups have been using SRC to calibrate detectors and filters that will go up
into orbit in the fall of 1998 with the AXAF X-ray telescope (Advanced X-ray Astrophysics
Facility).
The latest results come from a MIT-Harvard team that collaborated with the Canadian group
at the Canadian double crystal monochromator (G. Prigozhin, J. Wu, and E. Hallin). On very
short notice (first contact in early December '96 with M. Bancroft, data taken in January
'97) the absolute absorption coefficients of silicon compounds were determined around the
Si K edge. Absorption spectra of Si, SiO2 , and Si3N4 are essential for calibrating the
CCD detectors in the Imaging Spectrometer of the AXAF. It will quantitatively measure the
X-ray flux from hundreds of stars, galaxies, quasars, star remnants, and interstellar dust
with high resolution.
A Penn State team led by Leisa Townsley just completed a series of filter transmission
tests for the ACIS spectrometer of the AXAF satellite. Using the multilayer-beamline in
collaboration with Jim MacKay, Townsley made soft x-ray transmission images of thin
optical blocking filters in the energy range from 270 eV to 1860 eV. These filters,
composed of polyimide and aluminum, shield the X-ray CCD detectors mentioned above from
visible light. Because of the excellent stability of the stored beam at SRC, the
transmission images were able to resolve 0.5% variations in film transmission in 0.7 mm x
0.7 mm pixels over a film that is 150mm x 25 mm in size. These filters are
mission-critical, i.e., a single point failure component in NASA's language. That means,
there is no backup in this $ 1.2 billion mission, and servicing by the Space Shuttle is
not an option.
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PGM UPDATE
A second grating was just received for the plane grating monochromator, which is one of
the new undulator beam lines to become operational. The first grating had an efficiency
that was too low by an order of magnitude. Together with the grating exchange, other beam
line improvements are being implemented. It is expected that the beam line will be
operational in about a month. At that time, proposals for beam time will be solicited.
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SCIENTA ANALYZER UPDATE
Hartmut Hoechst went to Sweden for the first series of tests of the Scienta SES-200
electron spectrometer. At 2 eV pass energy a full width at half maximum of 5.6 meV was
achieved in gas phase spectra of the Xe 5p3/2 transition using a resonance lamp. Part of
the angle multidetection software and lens tables still needs to be fine tuned at Scienta
prior to shipment of the instrument which is scheduled to be tested at SRC in the middle
of August.
Jenice Con Foo joined SRC as postdoc in June, working with Hartmut to connect the Scienta
analyzer to Aladdin and to assist users in working with this new, top-of-the-line
instrument. She has extensive experience with angle-resolved photoemission, using a
toroidal analyzer built by an Australian group and operated at BESSY in Germany.
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NEW GROWTH CHAMBER FOR MAGNETIC
NANOSTRUCTURES
A group of SRC users (M.G. Lagally, W. O'Brien, J.F. MacKay, F.J. Himpsel, B.P. Tonner)
is working on a new growth chamber for magnetic nanostructures. It combines sputtering
with MBE, which makes it possible to investigate the effects of morphology on magnetism
and to compare commercial sputtering processes with lab-based MBE techniques. In use it
will be coupled to one of three existing chambers that utilize synchrotron radiation for
the study of magnetic films, i.e., magnetic circular dichroism, spin-resolved
photoelectron spectroscopy, and x-ray resonant magnetic scattering. An instrumentation
proposal was submitted to NSF, received all excellent reviews, and is likely to be funded.
This system that should be able to lead SRC into the future by making it possible to
prepare sophisticated nanostructures at a synchrotron.
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Honors for SRC Researchers and Users
Franco Cerrina was elected Fellow of the IEEE for his work on applications of
synchrotron radiation to X-ray lithography, X-ray microscopy, and X-ray optics delivery
systems.
Tom Kuech was named the Milton J. and A. Maude Shoemaker Chair in Chemical Engineering at
the University of Wisconsin- Madison.
Art Nelson was awarded a Fulbright Grant to study and conduct research in Italy.
Krista Mullman received the Aladdin Lamp Award (see "ALADDIN LAMP AWARD")
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