REU Research Project List, 2003
Here is the latest information we have regarding REU
research projects for the 2003 program. This page will be updated
frequently—the list of projects will continue to change, so please continue to
visit!
The projects and groups listed below are intended to provide
interested students with an overview of research offerings in the Department of
Physics, University of Washington. The list is not inclusive, but it is
representative of the breadth of research opportunities—both theoretical and
experimental—within the Physics Department and INT.
Students with particular interests should feel free to ask Jerry Seidler or Alejandro Garcia whether a special
project can be designed: this has been done successfully in past years.
Condensed Matter Physics
Physical adsorption of simple gases and molecules on carbon
nanotube bundles
Faculty: Oscar E. Vilches
My research group is currently measuring the heat capacity
of 4He adsorbed (deposited) on bundles of single-wall, closed-end carbon
nanotubes (SWNT) in the temperature range between 1K and 6K. It is measuring
also the adsorption characteristics for Kr on the same SWNT bundles at temperatures
above 77K. Planned at present are additional measurements on molecular oxygen
(adsorption above and below 77K) and hydrogen (heat capacity between 1K and
20K). The REU student will join one of these projects which typically require
long data acquisition runs. The group (two graduate students, two
undergraduates, and myself) meets formally once a week to discuss current
progress, ongoing experiments, and plans for the future; everyone shows what
they are involved in. We all meet informally every day. These systems are
interesting because they are representative of matter in one, two, and three
dimensions. Crossovers in dimensionality, plus the possibility of different
states of matter are important topics in condensed matter physics and
statistical physics. Depending on funding, we may be involved also in X-ray
scattering experiments to determine the structure of adsorbed molecules.
Dynamics at Ice Surfaces
Faculty: Sam Fain
Water is an ubiquitous and important molecule appearing in every
environment on Earth. Extraterrestrial water condenses at such low
temperatures that it forms an amorphous solid, which has diffusion
properties that are important to chemical reactions occurring in space.
Water is also the simplest hydrogen bonded molecule, providing a good
model for hydrogen bonded systems. We are making measurements to
determine the diffusion properties of water at these very low
temperatures. Our lab uses one of the most powerful microscopes in the
world, a variable temperature atomic force microscope capable of
operating between 50K and 1000K. This microscope is housed in an Ultra
High Vacuum (UHV) chamber and is capable of resolving single atoms of
Si over a wide range of temperatures. Undergraduates participate in
this research by designing and constructing ancillary devices and
analyzing data obtained with this apparatus.
Parallel Calculations of Electronic Structure and Response
Functions
Faculty: John J. Rehr, AL Ankudinov
This project deals with calculations of electronic response
functions, such as the absorption and emission of x-rays, based on parallel computational
algorithms. Our codes are based on a real space Green's function (RSGF)
formalism which is applicable to nano-scale systems of order 103
atoms.
Linear and Nonlinear Elasticity of Foams
Faculty: Jerry Seidler
Elastic foams are very interesting from both an applications
and a theory viewpoint. One long-standing problem has been a disconnection
between simulation, theory, and application. The best simulations predict the
elasticity at very small strains, the most reliable theory ignores the real
disorder in the materials, and the industrially-interesting regime is often at
high strains where neither the simulations nor the theory applies. In this
project, we will build a new apparatus to directly measure the stress-strain
relationship for polymer foams over five decades in strain, spanning the
low-load linear regime to the initial onset of non-linear elasticity. This data
will allow a critical test of the reliability of existing simulations and
theory.
Wavelet Analysis of Inhomogeneous Materials
Faculty: Jerry Seidler
Although the comprehensive understanding of crystalline
materials stands as one of the cornerstones of modern physics, the theoretical
and commercial importance of nanoscale-amorphous or microscale-inhomogeneous
should not be overlooked. Granular matter, foams, and paper are central in more
than 20% of the GNP of the United States and are also materials of ongoing
research interest in condensed matter physics. My group has recently developed
an apparatus for micron-resolution studies of these materials in 3-dimensions.
We have used this apparatus to perform the first precise experimental work on
3-D structure of granular matter in almost 50 years, the first 3-D studies of
many classes of solid foams, and the first truly fiber-level studies of the 3-D
structure of paper. The question is: How do you capture the important
statistical aspects of a structure with only short-range order? In this
project, we'll investigate the use of wavelet analysis and other tailored
orthogonal-polynomial decompositions to address this question. Strong math
skills and some programming knowledge are desirable for students interested in
this project, although no prior knowledge of wavelets analysis is necessary.
Building Simulated Materials by Cellular Automata
Faculty: Jerry Seidler
In computational statistical physics, a key question is
often: Does nature specify equations or algorithms? The realistic simulation of
real disordered materials (such as foams, powders, and a range of hard and soft
biological tissues) pose unique technical problems related to this question.
Foremost among these problems is the difficulty of creating an ensemble of
simulated materials with the same structural correlation functions as a class
of real material. Unfortunately, many methods for generation of simulated
disordered materials are known to be either statistically unfounded or only
weakly relevant to real materials of interest. In this project we will review
the prior methods for generating simulated disordered materials, and then
investigate several new ideas based on Bayesian statistics and efficient
computation by cellular automata. This project is a good fit for students with
a good computing skills and a strong interest in stochastic processes,
simulations, or nonlinear physics.
Electrolytic gating of nanotube and nanowire transistors
Faculty: David Cobden
It has recently been shown that an individual carbon nanotube immersed
in an aqueous electrolyte can be gated electrolytically, by applying a
suitable voltage to a counter electrode. (By 'gating' we mean that the
charge density on the nanotube can be controlled, by analogy with that
in the channel of a field effect transistor). When the nanotube has
electrical leads attached, he resulting 'wet molecular transistor' can
have an extraordinarily high transconductance, limited by quantum
effects. In the Nanodevice group we make (or are developing) similar
devices from inorganic nanowires (down to 10 nm in diameter), and single
organic molecules, as well as from single-wall carbon nanotubes (down to
1 nm diameter) which we grow ourselves. In this project we will modify
our probestation, currently employed for initial characterization of new
devices, to carry out 'wet gating' on these new nanodevices. The
results should teach us more about the physics of nanostructures and
about their potential applications in electrochemistry and sensing.
Physics
Education Research
Research-based
Instructional Strategies for Teaching Physics
Faculty:
Lillian C. McDermott, Paula Heron, Peter Shaffer
The Physics
Education Group conducts research on student understanding of physics and uses
the results to guide the design of instructional materials, which are intended
for national distribution. The effectiveness of these curricula is assessed at
the University of Washington and at many other institutions. REU students will
have the opportunity to participate in programs shaped by the group's research,
such as the summer program for K-12 teachers and the tutorials for the
introductory physics course. In addition to taking part in classroom
activities, previous REU participants assisted in investigations of the effect
of different instructional strategies on student understanding of important
fundamental concepts.
Nuclear Astrophysics
Weak Interactions, Symmetries, and Neutrinos
Faculty: Peter Doe, Steve Elliott, Hamish Robertson, and John Wilkerson
In addition to SNO (see below), our group is involved in a
number of projects probing the weak interaction and neutrino properties.
Current projects underway include emiT, a precision neutron beta decay
measurement that is testing time-reversal invariance, as well as SAGE, the
Russian American Gallium Experiment. On SAGE we are involved in the analysis of
data from this gallium based solar neutrino experiment (an experiment sensitive
to the low-energy p-p fusion neutrinos). We are also participating in new
experiments. One, called KATRIN, will attempt to make a direct measurement of
the neutrino mass via tritium beta decay. Two other experiments, MOON and
Majorana, will use double beta decay to attempt an indirect, but very sensitive
measurement of the neutrino mass. Most of our experiments have to be performed
underground to escape the cosmic ray backgrounds. To this end we are actively
participating in the establishment of a National Underground Science Laboratory
(NUSL). An REU student is encouraged to consider working with us in any of
these areas. More details of all these research are available at:
http://ewiserver.npl.washington.edu/
The Sudbury Neutrino Observatory
Faculty: Peter Doe, Steve Elliott, Hamish Robertson, and
John Wilkerson
The Sudbury Neutrino Observatory (SNO) is a massive, heavy
water Cerenkov detector in operation 2 km underground in Sudbury, Ontario.
SNO's primary mission is the study of solar neutrinos, It is also measuring
atmospheric neutrinos, and it is constantly monitoring for neutrinos emitted
from nearby (galactic) supernovae. Using its unique ability to distinguish
between neutrino flavors, SNO, in conjunction with the Super-Kamiokande
detector, has provided the definitive resolution of the long standing "solar
neutrino problem," where all existing experiments observe fewer neutrinos
from the sun than predicted by theory. We now know that neutrinos have mass and
oscillate between flavors. Work at UW in the summer of 2002 by our group (4
Faculty, 2 postdoctoral fellow, 8 graduate students) will concentrate on
analysis of the data being collected to further refine our understanding of
neutrino properties. In addition we are making final preparations to upgrade
the neutron detector system that will be used by SNO to make the key
measurement of neutral-current neutrino interactions. There are numerous
interesting hardware, software, and data analysis research opportunities
available. More information on SNO, plus other useful links, can be found at
our web site:http://EWIServer.npl.washington.edu/sno/sno.html
Nuclear Physics
Testing the Isobaric Mass Multiplet Equation
Faculty: Alejandro Garcia
We work on experiments on nuclear physics to search for new
physics, or to understand issues related to searches for new physics. During
this summer, we will try to determine with an accuracy of 10^{-8} the mass of
an excited state in 32S with isospin number T=2. This would allow the most
stringent test of the Isobaric Mass Multiplet Equation and will yield improved
accuracy to a measurement of the electron-neutrino correlation in 32Ar beta
decay.
Beta asymmetry from Neutron beta decay using UCNs
Faculty: Tom Bowles, Alejandro Garcia
This project deals with measuring the angular distribution of electrons emitted from polarized Ultra Cold Neutrons (UCNs). UCNs are neutrons that have velocities of approx 5 m/s. At these velocities neutrons can be contained in guides and trapped. Because their energy is only about 1 micro-eV they can be polarized by simply making them go through a large (approx. 7 Tesla) magnetic field. Part of the work involves developping the hardware to trap the UCNs and to measure the electrons emitted in beta decay, another part will involve doing Monte Carlo calculations in the computer to understand potential systematic uncertainties and backgrounds for the experiment. The student will work on all these aspects, getting experience on all fronts-from theory through design to measurement.
Light Front Quantum Mechanics
In 1947 Dirac introduced a new form of relativistic quantum
mechanics in which the variable ct +z acts as a "time" coordinate and
ct-z acts as a "space" coordinate. This so-called light front
formalism was largely forgotten until the 1970's, when it turned out to be
useful in analyzing a variety of high energy experiments. Despite the
phenomenological success of this formalism, it has enjoyed only limited use in
computing wave functions of particles and atomic nuclei. The present project is
devoted to using the light front formalism to solve quantum mechanics problems
involving bound and scattering states. A mathematically strong REU student
would learn about relativistic quantum mechanics through the process of solving
the relevant relativistic equations. This project would involve working on
interesting and timely topics and could provide great preparation for graduate
school quantum mechanics, field theory or even string theory. Gravitational Physics Sub-millimeter-scale tests of the gravitational
inverse-square law and other precision tests of "gravitational"
physics Faculty: Eric Adelberger, Blayne Heckel, Jens Gundlach The Eot-Wash group is testing an exciting prediction that
Newton's inverse-square could break down at length scales less than 1
millimeter. If verified experimentally, this prediction would provide strong
evidence for more than 3+1 dimensions; i.e., that some of the "extra
dimensions" of modern theories have observable consequences. Our
experiments employ novel torsion pendulums and rotating attractors. Three REU
students from 2000 and 2001 worked on the first version of this experiment,
which recently appeared in Physical Review Letters. In 2002, an REU student
worked on a second-generation experiment that proved down to length scales
below 100 micrometers. New projects will include designing and constructing an
electrostatic or gravitational "torsion fiber stiffener" that may
increase the resonant frequency of the torsion pendulum without increasing the
fiber noise. We are also making torsion balance measurements with a
spin-polarized pendulum to test CPT symmetry and to search for new spin coupled
forces, and working on an "anapole" pendulum to make very substantial
improvements on testing for a tiny but finite photon mass. REU projects
associated with these last two projects involve testing the magnetic properties
of the pendulums and developing improved magnetic shields. Other
instrumentation or computer projects will doubtless arise as time progresses.
Our lab is well-equipped with instrumentation, machine and electronic shops so
that plenty of resources are available for attacking these problems. You can learn
more about our group by clicking on the Eot-Wash Gravity Group on the
University of Washington Physics Department homepage. Particle Astrophysics WALTA
WALTA (Washington Large Area Time coincidence Array) is a
project to investigate the highest energy cosmic rays with the participation of
middle and high school students and teachers throughout the Seattle area.
Particle detectors and front-end electronics are sited at high schools and
linked to UW via the schools' Internet connections. The school network forms an
extensive air shower (EAS) array suitable for detection of extremely high
energy cosmic ray showers. Twenty schools are already participating, and during
Summer, 2003, we will hold a workshop to train teachers from another set of ~10
schools. REU students will assist with detector development and installation,
preparation of materials for the summer workshop and classroom use, and
maintaining contact with teachers and students. Atomic Physics Precision Measurements on Single Trapped, Laser-Cooled Ions
Our experimental work involves trapping single atomic ions
in an ultra-high vacuum and bringing them essentially to rest using the
radiation pressure from laser beams ("laser cooling"). Our motivation
is to observe simple atomic systems in nearly complete isolation, which will
ultimately enable us to make a single-ion atomic clock which is accurate to
about one second in the lifetime of the universe. Interested REU students can
help our efforts by constructing simple electronic or mechanical devices which
will be used in the experiments. Particle Physics Studies of the performance of planned gamma ray telescope
We at the UW have the lead in performing simulations of the
response of GLAST, a gamma ray detector to be launched in low-earth orbit in
early 2006, to incoming particles. We are involved in planning and executing
such simulations, modeling a variety of sources of particles, some representing
noise, and some the sort of signals we hope to study, like gamma ray bursts.
There are several projects that a student could contribute to; they would
involve some programming experience in C or C++. (We actually use C++). Computational Astrophysics Planetesimal Dynamics
From planet formation to planetary rings, from fragile
comets and asteroids to sandpiles, there is a large diversity of problems
related to planetary science that can be addressed with numerical simulations.
For example, the surprising configurations of planetary systems recently
discovered around nearby stars imply that planets can undergo large-scale
radial motions during their formation. It is known that planetesimal scattering
can cause a planet's orbit to shrink and circularize, but numerical simulations
are needed to quantify this process for various disk parameters. As a different
example, the spectacular breakup of Comet Shoemaker-Levy 9 and measurements of
remarkably low bulk densities in some asteroids imply that small bodies in our
Solar System may not be solid monoliths as we once thought. Numerical
simulations reveal how these fragile bodies evolve but there are many
parameters to explore. At even smaller scales, there are interesting topics in
granular dynamics to investigate, such as self-organized criticality in
sandpiles. The chosen project would provide experience performing simulations
with sophisticated numerical code on a cluster of workstations and carrying out
some analysis and visualization. For more information, visit
www-hpcc.astro.washington.edu or email trq@astro.washington.edu.
Faculty: Jerry Miller
Faculty: R. J. Wilkes, T. H. Burnett
Faculty: Warren Nagourney
Faculty: Prof. Toby Burnett
Faculty: Tom Quinn