THE ELECTRONIC
ALADDIN NEWSLETTER NO. 13
July / August 1997
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NEW RESOLUTION RECORD IN
SPECTROMICROSCOPY
Pupa DeStasio and collaborators have achieved a new resolution record of 0.05 microns
in photoelectron spectromicroscopy with synchrotron radiation. Thereby, they crossed the
0.1 micron barrier, which is essential for analyzing the microcircuits in today's
semiconductor industry. The resolution has to be better than the typical feature size of a
microprocessor or DRAM, which is reaching a quarter micron in commercial devices and less
than that in exploratory circuits. Pupa and coworkers used MEPHISTO, a second-generation
photoelectron microscope, which is being used for a variety of studies, ranging from boron
incorporation into brain cells for cancer therapy to motor oil residues on stainless
steel, a collaboration with Mike Bancroft of the Canadian Group and industry (Exxon and
Chevron).
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FIRST HIGH-TEMPERATURE SUPERCONDUCTOR
FILM GROWN AT SRC
In a Switzerland-U.S. collaboration, Marshall Onellion, Torsten Schmauder, Giorgio
Margaritondo, Davor Pavuna and coworkers have developed a growth chamber that allows the
deposition of high-temperature superconductors in situ at the SRC. It uses laser ablation
to achieve molecular layer precision in the deposition and to fabricate sandwich
structures containing superconductors, insulators, and metals. Sophisticated growth
chambers, such as this and the magnetic growth system being developed at the SRC, make it
possible to fabricate nanostructures with tailored electronic properties.
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DETECTION OF DILUTE SPECIES BY
FLUORESCENCE
Adam Hitchcock and collaborators at the Canadian double crystal monochromator have set
up a 9-element fluorescence detector (Ortec IGLET) that provide a dramatic improvement in
the detection of dilute species compared to the previous electron detector. EXAFS and
NEXAFS data of Ge crystals containing 9% Si gave very high signal-to-background. For
access to this instrument contact Mike Bancroft (scigmb@uwoadmin.uwo.ca)
and Jacek Lipowski (lipowski@chembio.uoguelph.ca).
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PGM BEAM LINE READY FOR USERS
Major changes have been performed to the PGM beamline. The PGM is currently
being aligned with the new grating. Preliminary results indicate
a gain of at least a factor of three in intensity. The beam line
is being opened for general users. Beam time proposals are being
solicited for review by the Program Advisory Committee. In order
to accelerate the process, the short Rapid Response Form will
be used, which is available on-line at: http://www.src.wisc.edu/src/currentusers/online_forms/
beamtime_rapid_response/default.html
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NEW SRC INFRARED MICROSCOPE INSTALLED
A new NicPlan infrared microscope has been installed at the IR beamline.
Knife edge experiments have shown significant improvement in the
signal to noise ratio using synchrotron radiation as compared
to the thermal source. At a wavelength of 2 micron and for a 10
micron area at the sample position, the gain in signal to noise
is more than a factor of 10. The beamline is ready for experiments
and interested users should contact Tim May (tmay@src.wisc.edu).
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LAUE CAMERA AVAILABLE TO USERS
A commercial Laue camera sponsored by Ames Lab (Cliff Olson and Dave Lynch) is now
installed in the clean room and available for users. Please contact Brian Oberbeck (boberbeck@src.wisc.edu) for access.
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REDUCTION OF HIGH-FREQUENCY BEAM
OSCILLATIONS
High-frequency beam oscillations (e.g., at 60 and 720 Hz) have not been noticed much in
the past since most experiments have operated with time constants of about a second. The
new Fourier-transform infrared beam line, though, is very susceptible to such
oscillations. In an effort to eliminate sources of such beam noise, the user ac power
transformers were moved into the center of the ring, several meters further away from the
orbit. An immediate reduction of the 60 Hz component of the vertical beam motion was
observed, but not eliminated. The largest source of 720 Hz noise was the large filter
choke at the head end of the dipole magnet chain. The choke had been located less than a
meter from the electron orbit. Recently this choke was moved into the power room inside
the ring. This all but eliminated the vertical 720 Hz motion (at one vertical monitor the
motion was reduced from 24 mm PP of mostly 720 Hz to 6 mm predominantly at 60 Hz). Any
remnant 720 Hz motion is small compared to the 60 Hz (and several higher harmonics) motion
that still remains. The search for other sources of power line related noise is
continuing.
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ON-SITE TEST OF THE SCIENTA ANALYZER
AUG. 13-20
The Scienta photoelectron spectrometer has been delivered to SRC and will go through
its final, on-site testing during Mid-August. Users interested in seeing the performance
can contact Hartmut Hoechst (hhochst@facstaff.wisc.edu),
who supervises the project.
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HONORS FOR SRC RESEARCHERS
Prof. John Weaver, Univ. Minnesota, long-time user of the SRC, was named R&D
Scientist of the Year (1997).
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