X-RAY RUNS: Apply for Beamtime
2017 Nov 1 - Dec 21
2018 Feb 7 - Apr 3
2018 Proposal/BTR deadline: 12/1/17
2018 Apr 11 - Jun 4
2018 Proposal/BTR deadline: 2/1/18
The REU work mentioned below was sponsored by the
National Science
Foundation REU grant PHY-9731882. CHESS additionally sponsors outreach
work for undergraduate and graduate students seeking to broaden their
research horizons. This is, of course, over and above the very large
number of students who are trained as normal CHESS users.
Research Experiences for Undergraduates (REU)
Each year several undergraduate students do summer research at CHESS via
the REU program. The REU program is a NSF-funded program for
undergraduates who wish to gain research experience at major scientific
facilities. Undergraduates at U.S. colleges who wish to apply for summer
research at CHESS may apply via two associated REU programs:
1.
The Cornell Laboratory of Elementary Particle Physics (LEPP) REU
program. LEPP operates Wilson Laboratory, the parent organization of
CHESS.
2.
Many Cornell researchers who work at CHESS are also members of the
Cornell Center for Materials Science (CCMR), and will sponsor students
in synchrotron radiation-related research.
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2004
Ismail Degani, Undergraduate computer science major, has designed a
remote crystal-centering software package that now allows beamline users
to position protein crystals in the x-ray beam with a few clicks of the
mouse. The high-resolution display uses state-of-the art streaming
digital video that can be viewed on any computer console outside the
experimental hutch, including remote sites. The system has been in
operation during the past year. The current system is not only faster
than manual positioning, but also more accurate, allowing smaller
protein crystals to be rapidly positioned for structural studies.
Eric Angle, Undergraduate from Cornell University, led the design and
construction of a novel high-pressure gas loading system for diamond
anvil cell (DAC) specimen chambers. DACs are used to explore the
properties of gases at pressures encountered deep within the outer
planets, or for use as pressurization media for studies of minerals and
metals deep within the earth. Loading the DAC with gases has
historically been a major difficulty limiting many studies; this system
overcomes this difficulty. The DAC gas loading system considerably
extends capabilities in high-pressure science possible at CHESS.
____________________________________________
2003
Richard Clinite, as a recent Cornell Undergraduate seeking some
real-world experience in physics, Rick spent the summer of 2003 working
on technical upgrades to the CHESS D1 Small-angle scattering station. He
successfully interfaced the ADC serial port slits with the station
control software SPEC and troubleshot using them at the D1 beamline
station. He worked with CHESS Computer Specialist Phil Sorensen learning
how to configure and test each motor, as well as write and debug macro
language software that moved the multiple slits in useful ways. This was
the first time this type of motor controller has run at CHESS.
Sophie McGough, from the University of California, Los Angeles, joined
CHESS in the middle of summer 2003 and, having practical research skills
and experience in computer programming, she was quickly and enthusiastic
deployed to work with CHESS Staff Scientist Ken Finkelstein to develop
programs for data reduction and modeling of complicated x-ray scattering
geometries. This interest was well matched to the project needs. She
first worked to interpret 2-dimensional x-ray scattering data recorded
by large area 'CCD' detectors. A second project involved developing
tools to model the influence of focusing optics on "coherent
diffraction" patterns; i.e. when an x-ray beam made up of waves with
well-defined relative phase illuminates a sample. An ERL x-ray source
should provide beams of this quality, so it is important to anticipate
such effects. The major challenge for Sophie was to learn to "think in
reciprocal space" since x-ray diffraction patterns are naturally
described in terms of the Fourier transform of real space structure in
the sample. As soon as she understood this concept the programs began to
flow! In both project she produced genuinely useful code that is
presently being tested.
____________________________________________
2002
Soumendra Banerjee, a Cornell Undergraduate in Applied and Engineering
Physics, has worked on two projects during this summer to help improve
our capabilities in x-ray imaging. His first project involved writing
software to automate direct imaging of x-rays using a CCD area detector
produced by the MedOptics Corporation. His second project involved
working with Rong Huang and Don Bilderback to collect x-ray fluorescence
spectra using microscopic x-ray beams. In a typical measurement, a 10
micron x-ray beam is scanned across a specimen in an array of fine
points. At each point the x-ray beam excites fluorescence from the
specimen and the full spectrum is recorded.
Anton Kriksunov, a junior at Ithaca High School, worked to develop a
web-interactive database for keeping track of scientific publications.
As a growing organization, CHESS has growing needs to keep track of the
scientific and technical report generated by both staff and users. The
scientific and technical staff members produce large numbers of
technical journal articles and presentations. CHESS users publish, on a
whole, almost one paper for each day that CHESS is open for business. We
need a system to keep track of all this output so that we can remember
and recall information as well as report the laboratory output to the
funding agencies. Anton has designed a system that can keep track of six
kinds of publications: journal articles, books and chapters, patents,
conference presentations, masters and Ph.D. theses, and internal staff
reports and presentations. This system utilizes a web interface for
entry, editing and searching for information. This will spread the
onerous task of data entry among the staff and users and allow anyone to
search the database.
____________________________________________
2000
Melissa Skala, is a junior physics major from Washington State
University. As an REU (Research Experience for Undergraduates) she
joined CHESS for a 10 week period this summer working towards using MCP
optics (Micro Channel Plates) in fluorescence imaging. She obtained and
characterized the commercially available MCP optics using the F3 and D1
beamlines, gaining much hands-on experimental experience. These optics
are composed of thousands of microscopic pores, which could be used as a
defining slit to directly image the fluorescence from a two dimensional
sample onto a area detector.
Scott Forth, an undergraduate from Oberlin College (Oberlin, OH) spent a
summer as an REU participant studying focusing of x-rays with refractive
optics. His work consisted of designing, building, and testing several
compound refractive x-ray lenses at CHESS. He achieved a gain of 2.5
with one such lens, while focusing a 12 keV beam to a width of
approximately 10 microns. Such a beam could be used in various
experiments due to its extremely small width and high intensity.
Jason Flannick, a Cornell undergraduate, worked during summer 2000
writing a Java application display program for the CHESS signal
monitoring system. We have an existing system to monitor hundreds of
critical parameters of the CHESS x-ray beamlines. This system has a
limitation of only recording data once per minute. Jason wrote a new
application that updates information once every 2-3 seconds.
Sami Rosenblatt, a Cornell Physics graduate student, worked with staff
scientist Ken Finkelstein to design new focussing x-ray optical crystals
based on silicon nanofabrication techniques. The project involves using
the PT-770 Bosch Process Reactive Ion Etching machine to etch silicon
wafers to a depth of 900 microns. We hope this fabrication technique
will provide optics with much finer detailed grooves than can be made
with standard mechanical machining techniques. Finer detail should
result in more flexible optical elements with high pass-through
efficiency and much smaller focal spot sizes; these two features will
provide more usable photon flux into small specimens.
Anselm Levskaya is a Cornell freshman physics and math major. For the
past year he has assisted in the design of high heat load components for
the G-line expansion. Using the ANSYS finite element analysis code he
has modeled the thermal and structural response of the G-line Crotch and
B11W vacuum chamber to the intense power of the G-line 45 pole wiggler.
His recent results were presented at the 2000 CHESS users meeting in
June. Further he has analyzed the response of the A1 water-cooled
mirror, in particular the critical effect of splitting the wiggler beam
into two using the edge of the mirror. His calculations led the design
of this cutting edge optic.
Dan Pringle was a first-year graduate student in physics. He worked with
staff scientist Qun Shen in June-August 2000 in the development of a
phase-sensitive reference-beam x-ray diffraction technique to obtain
phases directly from a crystallography experiment. The principle of the
technique is to combine the phase-sensitivity of three-beam diffraction
with an oscillation camera that is the most popular data collection
method in protein crystallography. During the period Dan finished the
construction and the alignment of a new five-circle kappa diffractometer
that is dedicated for the phase-sensitive measurements. He authored a
computer routine to control the kappa goniometer so that an arbitrary
Bragg reflection can be oriented onto the oscillation axis based on an
initial oscillation image. Both the new hardware and the new software
were tested successfully during a three-week experimental run in July at
CHESS C-line on real protein crystals. During the run Dan was a full
participant in equipment set-up and in experimental data collection. In
the last few weeks of his stay at CHESS, Dan made further improvements
to the kappa instrument and performed extensive data analysis that
included peak indexing and integration from oscillation images and curve
fitting to obtain phases from the measured reference-beam profiles.
Dan's contributions to this work have been extremely valuable. As a
result, two publications are being planned to document the advances that
have been made at CHESS during this period.
Ivan Bazarov, a graduate student in Physics at Cornell, has been
involved on the machine physics side of studying machine parameters for
a possible new a dedicated synchrotron radiation facility called (at
this point) an Energy Recovery Linac light source. Ivan has been
calculating a trial machine lattice for both the superconducting linear
accelerator portion as well as the attached one-turn storage ring. For
doing these calculations, he has written a Pascal computer program to
implement the calculation of the needed strengths of the various magnets
and the beta functions.
____________________________________________
1999
D. J. Cooker (SUNY Albany, NY) was an REU student working with Don
Bilderback to successfully produce one-bounce capillary optics for
millibeam experiments. Several capillaries were pulled and characterized
with x-rays.
Megan Toaspern (REU, Gettysburg College, PA) imaged the location of zinc
in plant leaves with x-rays. The hyperaccumulator Thlaspi caerulescens
from Prof. Leon Kochian's laboratory (USDA & Cornell Univ.) can absorb
as much as 2% of its biomass in the form of zinc and still keep growing.
The x-ray results show that ordinary non-accumulator plants have their
"arteries" clogged with zinc and die with too much zinc. The
hyperaccumulator, on the other hand, has the ability to move the zinc to
the periphery of the plant leaf. This outstanding new research result
was featured at the AIP Centennial in Atlanta in March, 1999. See an
on-line Research Highlight on Megan's work.
Brock Aranson of the School of Applied and Engineering Physics completed
a Masters of Engineering degree with Don Bilderback, awarded Spring of
1998. Brock's project was to design custom a x-ray sensitive photodiode
with a hole in the center to pass an x-ray microbeam. With this
geometry, we hope that more solid angle can be subtended during
microprobe measurements. This is a project with the Cornell
Nanofabrication Laboratory (Hercules Neves, Cornell). Not only did Brock
design the photodiode, he fabricated prototypes in silicon. The
prototypes didn’t function very well as diodes and are into the next
round of redesign and fabrication.