REU projects list - May, 2002
Nuclear Physics
TITLE: Germanium Detectors for Nuclear Structure Studies (experimental)
SUPERVISOR: Prof. T. Glasmacher
ABSTRACT:
We have implemented the world’s largest array of highly-segmented
Germanium detectors used for in-beam gamma-ray spectroscopy with
exotic beams. We invite a student to participate in experiments with this
new photon spectrometer at the NSCL. Stable nuclei are well understood,
but very little is known about exotic nuclei – nuclei with extreme
neutron-to-proton ratios. Our experiments measure quantum mechanical
observables which elucidate the change in nuclear structure when moving
from stable nuclei towards very exotic nuclei. Familiarity with a UNIX
scripting language (such as Tcl/Tk) is desired.
More information at http://groups.nscl.msu.edu/gamma/
TITLE: LEBIT - Trapping of rare isotopes (experimental)
SUPERVISOR: Prof. G. Bollen
ABSTRACT:
A physicist's dream - place a single particle freely in space and study
it. Such a dream will become reality for ions of rare isotopes with
LEBIT at the NSCL. LEBIT - the Low Energy Beam and Ion Trap facility -
will allow us to capture single rare isotopes in devices called ion
traps. One kind of experiment foreseen is a precise mass determination
of the trapped ions. This allows us to determine how strongly the
nucleons are bound together, an important information if we want to
understand very exotic nuclei with large different neutron and proton
numbers. Penning traps, which employ a strong several Tesla magnetic
field for the ion storage, are ideal for this kind of measurement.
We are looking for a highly motivated and experimentally skilled student
who wants to help to realize this dream by contributing to the
development, construction, and testing of LEBIT and its components.
Possible projects range from improving the field stability of the
superconducting magnet that provides the 9.4 Tesla field for the Penning
trap, simulating and testing the properties of other ion trap and ion
guide components in LEBIT, to developing parts of the computer-based
control system.
TITLE: Measurement of fragment transmission in the A1900 (experimental)
SUPERVISORS: Prof. B. Sherrill and Dr. A. Stolz
ABSTRACT:
The A1900 fragment separator at the National Superconducting Cyclotron
Laboratory is a highly selective and efficient filtering device that
uses superconducting magnets to select single isotopes from among the
hundreds produced in nuclear reactions. These individual isotopes can
be selected with high efficiency. With detector systems installed in
the A1900 the isotopes can be identified unambigously and it is
possible to reconstruct the flight path within the spectrometer.
During this project the transmission through the A1900 for different
isotopes should be measured and compared with Monte-Carlo simulations.
TITLE: Commissioning of the HiRA array (experimental)
SUPERVISORS: Prof. Bill Lynch and Dr. Betty Tsang
ABSTRACT:
This summer, we are completing a $0.5 MD silicon strip detector array
called HiRA. This is a multipurpose research instrument, whose first
measurements are designed to measure the masses of nuclei that may play
an important role in the energy production in X-ray bursters. Calculations
of the nucleo-synthesis of these nuclei on the surface of neutron stars predict
that they may be formed in rapid proton capture processes provided their masses
are of the right magnitude. The HiRA array, in its final stages of construction, will
permit these masses to be measured with the radioactive ion beams of the
Coupled Cyclotron Facility. An REU student working on this project will join
the team constructing and commissioning this device. The student will be build
and test equipment and will work on the experiments during which the
components of the array will be tested and commissioned.
TITLE: Imaging Nuclear Collisions (experimental)
SUPERVISORS: Prof. Bill Lynch and Dr. Betty Tsang
ABSTRACT:
By measuring two protons in coincidence and examining how their
emission rate depends on the difference between their momenta, we have
recently shown how it is possible to “invert” this information and obtain an
image of the nuclear reaction from which the protons are emitted. This
summer we would like to work with an REU student to apply this new
method to a wide range of different nuclear reactions. By analyzing
experimental data using these new tools, it should be possible for an
enterprising student to contribute significantly to the understanding of
nuclear imaging techniques and to the understanding of nuclear reactions,
in general. We also expect that there will be some opportunities to participate
in some experiments with our research group and gain some experimental
experience.
TITLE: Sweeper Magnet Focal Plane Detector (experimental)
SUPERVISOR: Prof. Michael Thoennessen
ABSTRACT:
The NSCL has recently finished a major upgrade and has begun an exciting
phase of new experiments. One of the new experimental equipment available
is the sweeper magnet focal plane detector. The construction will be finished
by this month and tests and first experiments will be performed during the
summer. The detector consists of two Cathode-Readout-Drift Chambers
(CRDC's,) for particle tracking, a multi-sampling Frisch Grided ionization
counter for energy loss measurements, and two plastic scintillation detectors
for energy determination. We invite a highly motivated student to participate
in all aspects of this project. Responsibilities would include setting-up and
debugging electronics, programming, and analyzing experimental data.
No previous experience is necessary, only the desire to learn and to be
an active participant in this detector's development.
TITLE: MoNA -- A Modular Neutron detector Array
SUPERVISOR: Prof.. Michael Thoennessen and Dr. Thomas Baumann
ABSTRACT:
Last year the National Science Foundation funded a 144 element
plastic scintillator detector array for the study of very neutron rich
isotopes at the NSCL. This project is a collaboration between Michigan
State University, Florida State University and 8 other colleges and
universities. Each school will be responsible for one layer (16 detectors)
of this array. The 16 MSU/FSU scintillators have been delivered to the
NSCL and they will be assembled and tested this summer. It is an ideal
project for an REU student to get involved, because she/he will learn the
fundamentals of scintillation detectors, electronics, data acquisition and
data analysis.
TITLE: The Modular Neutron Array
SUPERVISOR: Profs. Bryan Luther and Michael Thoennessen
ABSTRACT:
A new highly efficient time-of-flight neutron detector is being constructed
at the NSCL. The Modular Neutron Array, MoNA, consists of 144
individual detector modules based on 200 x 10 x 10 cm^3 plastic
scintillator bars. Thirty two of these detector modules will be assembled
and tested this summer at the lab. We invite a highly motivated student to
participate in all aspects of this project. Responsibilities would include
construction, component integration and testing. There will also be
opportunities to assist in the design and implementation of the data
acquisition electronics and software for the detector.
TITLE: Beta decay of extremely neutron rich nuclei and
their relevance for the origin of elements (expt. and theory)
SUPERVISORS: Dr. D. P. Santi and Prof. H. Schatz
ABSTRACT:
The project is related to one of the most important open questions
in science -- the origin of elements heavier than iron (see Discovery
magazine, Feb 2002). Simulations show that explosions of stars
(supernovae) are a possible place for the nuclear reactions that create
those elements. We performed a nuclear physics experiment to restage
the nuclear processes during a supernova explosion. These processes
involve nuclei that only live for fractions of seconds before they decay.
The analysis of the data will help to decide whether the proposed
astrophysical scenarios for the origin of the heavy elements are
acceptable or not.
The project involves computer analysis of existing data using PAW
and C++ codes. This includes modifying and expanding existing codes
as well as implementing new algorithms. Similar experiments are currently
performed at the NSCL, so as a member of the nuclear astrophysics group
there will be the opportunity to become familiar with experimental techniques
in nuclear physics as well as with astrophysical simulations.
Some familarity with C or C++ programming language would
be a prerequisite for this project.
TITLE: Excited-state nuclear moments by the Time-Differential Perturbed
Angular Distribution Technique. (experimental)
SUPERVISORS: Visiting Prof Andrew Stuchbery and Prof Paul Mantica
ABSTRACT:
The magnetic dipole moments of excited nuclear states give unique
information about the nuclear wavefunction. We are currently
investigating possibilities and designing experimental techniques to
measure excited-state nuclear moments in exotic isotopes produced
by fast-fragmentation reactions at NSCL. In the time-differential
perturbed angular distribution technique relatively long-lived isomeric
states are placed in a magnetic field where their spin precesses about
the magnetic field direction. The frequency of this precession, which is
proportional to the nuclear moment, is observed by measuring the
rotation of the radiation pattern when the state decays by gamma-ray
emission. This is an established technique in conventional nuclear
spectroscopy that must be adapted and optimized for new experiments
in the rare-isotope regime.
An REU student is invited to participate in this work, which will
provide the opportunity to develop generally useful skills in the design
of complex experiments and widely applicable data analysis procedures
like Fourier analysis and Autocorrelation techniques. Familiarity with
scientific programming is highly desirable. An orientation towards
experimentation would be an advantage, and a willingness to think
broadly and creatively about experiments will be essential.
TITLE: Gamma decays (theory)
SUPERVISOR: Prof. A. Brown
ABSTRACT:
Recent experiments at the NSCL and other laboratories have measured
the gamma decay schemes of very neutron-rich nuclei. The project will
involve calculations using nuclear structure models to obtain the energy
levels and decay scheme of these exotic nuclei. Comparisons to
experiment will be made when they exist, and predictions will be made
for those not yet measured. The project will involve methods for
graphical comparison of the results and a web based archive.
TITLE: Borromean Nuclei (theory)
SUPERVISORS: Profs. V. Zelevinsky and C. Bertulani
ABSTRACT:
"Borromean" is the class of quantum systems with the following interesting
property. The system consists of three or more subsystems. There is an
attraction between any two subsystems but not sufficiently strong to be able
to bind them. However the large system as a whole is bound. A perturbation
removing the coupling of any subsystem with the rest immediately breaks
down the entire system. The system exists only as a result of collective
interaction. The rare isotope of lithium-11 (3 protons + 8 neutrons)
considered as a three-body system (a core of lithium-9 bound with two
extra neutrons) is perhaps the best studied Borromean object; another
example of this type is the less studied system
``proton + neutron + Lambda-hyperon".
Since the attraction between the two neutrons in lithium-11 is a necessary
element of the total binding, it is expected that the neutrons are to be
correlated. One can hope to observe such correlations in reactions
breaking the nucleus. We suggest to study possible neutron-neutron
correlations in coordinates, momenta and spins by analyzing the wave
function of the Borromean system and possible break-up processes.
The decay of lithium-11 that generates entangled states of the two neutrons
can also be looked at from the viewpoint of the basic quantum postulates
(the so-called Einstein-Podolsky-Rosen paradox).
Some knowledge of quantum mechanics is desirable. Necessary
computing skills hopefully will be acquired in the process of work.
TITLE: Compound Hadron Model (theory)
SUPERVISORS: Prof. Pawel Danielewicz and Prof. Scott Pratt
ABSTRACT:
Simulations of ultrarelativistic nuclear reactions require
considerations of the production and decay of different
hadronic resonances. The resonances, their decay schemes and
reactions, the resonances are involved in, are well known for
low-mass reonances but less and less the higher the
resonance mass. Such situation is well known from nuclear
resonance states, where averaging is made over the resonances.
The averaged processes of resonance formation and decay are
described in terms of the density of resonance states and
geometry, utilizing time-reversal invariance, within the very
successful compound-nucleus model. The goal of the project is
to develop a compound-hadron model for the hadronic resonances.
Condensed matter physics
TITLE: Giant Magnetoresistance in Magnetic Multilayers. (experimental)
SUPERVISORS: Profs. J. Bass and W. Pratt
ABSTRACT:
Giant Magnetoresistance (GMR) in Magnetic Multilayers is of interest
both for the underlying physics and for technology--the read heads in
modern computer hard drives are now GMR multilayers. The MSU group
pioneered measurements of Giant Magnetoresistance in Metallic Magnetic
Multilayers with Current Flow Perpendicular to the Layer Planes, a
geometry that usually gives more direct access to the physics underlying
GMR. A specific project will be chosen after discussion with the REU
student. The project will involve sample preparation (using a
state-of-the-art sputtering system), sample characterization, and
measurement of magnetoresistance. The project might also involve
optical and electron-beam lithography in collaboration with a Ph.D. student or
Postdoc.
TITLE: Seeing is Believing: Mapping-Out Surfaces with Scanning
Probe Microscopy (experimental)
SUPERVISOR: Prof. S. Tessmer
ABSTRACT:
Nearly twenty years ago, physicists at IBM invented the first
scanning probe microscope (SPM) -- ushering in a new era for
the study of surfaces. By monitoring the electrical or mechanical
interactions between the surface of a material and a sharp tip, SPM's
can produce amazing pictures. For example, it is possible to directly
"see" the individual atoms that make up the material. In addition,
these microscopes can be used as local probes of the electronic
properties with incredible sensitivity. During the summer, we
will be assembling and an SPM system. Of particular interest
is the response of the apparatus to building vibrations, which
would be the focus of the REU project.
TITLE: Low-Temperature Physics (experimental)
SUPERVISOR: Prof. N. Birge
ABSTRACT:
Experiments in low-temperature physics require shielding of the sample
from external sources of noise, which can interfere with the experiment
or even heat up the sample. This is especially true in the field of
“mesoscopic physics”, where the samples have typical dimensions less
than one micron. Often the room temperature thermal radiation propagating
down the electrical leads to the sample is enough to overheat the electrons
in the sample and ruin the measurement. The two stages of filtering we have
now in my dilution refrigerator are adequate for our current experiments,
but may not be adequate for the future. Hence I would like to add a third
stage of filtering. An REU student could help us by learning about the many
different kinds of filters used, deciding which would be best for our cryostat,
and then building and installing the filters. This project is designed to optimize
the productivity of the student during a time when the condensed matter physics
labs will be moving to the new physics building.
TITLE: Solid state models (theory)
SUPERVISOR: Profs. T. Kaplan and B. Mahanti
ABSTRACT:
Two major types of approximation in solids, the Hartree-Fock
approximation (HFA) and the Local Density Approximation (LDA) give
quite different results for the important material LaMnO3, lanthanum
manganite. One of these differences is in the values of the “exchange
parameters” they predict. These parameters determine the spin wave
dispersion, which can be observed experimentally, by inelastic neutron
scattering. The central question for this project is, can such a measurement
distinguish between the approximations.
Certainly the answer is “yes, in principle”. But we want to know if it is
“yes, in practice”. The point is that the actual differences in the spin wave
spectra predicted are rather small (despite a qualitative difference in the
exchange parameters). Determination of the answer will require
comparison of the theoretical predictions (already known) with
experimental data which has already been obtained, but which has fairly
appreciable errors. The comparison will require statistical analysis.
TITLE: Monte Carlo Simulation Studies of Magnetic Nano-Clusters
SUPERVISOR: Prof. S. D. Mahanti
ABSTRACT:
It is now possible to synthesize nano-clusters of magnetics atoms
(containing 10-30 atoms) and investigate their magnetic properties using
Stern-Gerlach type measurements. These magnetic clusters have great
potential in future technological applications through novel cluster
assembled materials.
Before one can think of possible applications, one has to develop
a fundamental understanding of how the magnetic properties of these
nanoclusters depend on temperature, magnetic field, and other
physical parameters.
The REU project will involve Monte Carlo simulation studies
of the above magnetic properties using simple models to describe
magnetic interactions in clusters. Some of the results can be compared
directly with experiment. The project requires some basic knowledge
in computer prgramming (fortran and/or C++).
TITLE: Electronic Properties of Novel Thermoelectric Materials (theory)
SUPERVISOR: Prof.. S. D. Mahanti
ABSTRACT:
Thermoelectric materials are used in either solid-sate cooling devices
or for power generation from heat. Potential future applications are in
the area of cooling computer chips as they become smaller in size and
generate a lot of heat. Here we have a joint physics-chemistry-engineering
program where we synthesize new materials (chemistry), study their
structural and transport properties (chemistry and engineering) and
look at their electronic properties (physics).
The summer project will involve looking at the electronic properties
of some of the new materials. This will involve working with an advanced
graduate student to calculate electronic structure and if possible
use these results to calculate transport properties. The project requires
experience with Fortran and/or C++.
Prof. Mark Dykman (Quantum Computing)
Astronomy and Astrophysics
TITLE: How do elliptical galaxies form?
SUPERVISOR: Prof. Steve Zepf
ABSTRACT:
The goal of the project is to gain a better understanding
of how and when elliptical galaxies form by studying the properties
of their globular cluster systems. Globular clusters are long-lived
fossil records of the major formation episodes and can be used to
reconstruct the early formation history of galaxies. The specific
project will be to write computer programs to model the expected
properties of globular cluster systems for some formation histories
of elliptical galaxies that have been proposed. The models follow
straightforward rules that can be coded with a reasonable amount
of time and effort. The model predictions will then be compared
to observational data.
TITLE: Multiperiodicity among RR Lyrae Variable Stars
SUPERVISOR: Prof. Horace Smith
ABSTRACT:
RR Lyrae stars are pulsating giant stars, which typically change
in brightness with periods under 1 day. Some RR Lyrae stars
do not perfectly repeat their light changes from one pulsation
cycle to the next. Some show longer secondary periodicities, the
nature of which is still uncertain. Photometric observations of
RR Lyrae stars, some obtained with the MSU 60-cm telescope, will
be used to explore the multiperiodic nature of several of these
stars.
High energy physics
TITLE : Parton Distribution Functions (theory)
SUPERVISOR: Prof. Dan Stump and Prof. Wu-Ki Tung
ABSTRACT:
The Parton Model describes the quark structure of the nucleons
(protons and neutrons). One project would be to study different models
and their agreement with data from high-energy scattering experiments.
Another model would be to study predictions of future experiments
based on current parton model parameters, and the uncertainties
of the predictions. One definite project is to study and compare
examples from the new LHAP compendium of parton distribution
models.
Other possible supervisors in experimental high-energy physics
Prof. Joey Huston (experimental)
Prof. Carl Bromberg (experimental)
Prof. C. P. Yuan (theory)