========================

REU Projects Summer 2003

========================

---------------

NUCLEAR PHYSICS

---------------

TITLE: Simulations for experiments with the S800 spectrometer

(experimental/simulations)

SUPERVISOR: Prof. Remco Zegers

ABSTRACT:

For planning and analysis of experiments with the S800 magnetic spectrometer at NSCL a simulation code is being written to describe the response in detail. Although the new code will be partially based on existing code, many improvements and additions will have to be made (graphical output, possibility to add secondary detectors, event generators). We invite a highly motivated and creative student to work on the simulation code. The work would include the description of response of the various detector components, tracking particles through magnetic fields and implementation of kinematical procedures and provide a good opportunity to learn about the many aspects of doing experimental nuclear physics. Some experience and a strong interest in programming is a prerequisite for this project.

 

TITLE: The Mystery of Superbursts (theoretical/experimental)

SUPERVISOR: Prof. Hendrik Schatz

ABSTRACT:

Recently a new type of X-ray bursts has been discovered by space based X-ray observatories - the so called superbursts. These bursts might be powered by a new nuclear process - the photodisintegration of heavy nuclei, initiated by a small carbon explosion, on the surface of a neutron star. How much carbon is needed to really ignite such a process depends on the composition of liquid ocean covering the neutron star surface. Current models predict an ocean made of liquid palladium.

     In this project, computer simulations of the nuclear processes during thermonuclear explosions on the surface of neutron stars will be used to determine the ocean composition and its dependence on various nuclear physics parameters. The goal is to identify uncertainties that can then be addressed by future nuclear physics experiments. In addition, we will gain a better understanding on the conditions needed to trigger a superburst. This project involves programming in Fortran 77 on a Unix based system.

 

TITLE: MoNA – A Modular Neutron Detector Array

(experimental; available for 2 students)

SUPERVISOR: Prof. Michael Thoennessen and Dr. Thomas Baumann

ABSTRACT:

The Modular Neutron Detector Array (MoNA) funded by the National Science Foundation consists of 144 plastic scintillator detectors and is intended to study 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 is responsible for one layer (16 detectors) of this array. Almost all scintillators have been delivered to the NSCL and they will be ready to 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: Imaging Nuclear Collisions (experimental)

SUPERVISORS: Prof. Betty Tsang and Dr. Giuseppe Verde

ABSTRACT:

Interferometry has been used to determine the size of stars in astronomy. In nuclear physics, a similar method of measuring two charge particles (instead of photons) in coincidence, we can obtain an image of the nuclear reaction from which the particles 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: Production of Rare Isotope (experimental)

SUPERVISORS: Prof. Betty Tsang

ABSTRACT:

The most efficient method of producing extremely neutron rich isotopes is to be able to remove protons from a nucleus but keep the total number of neutrons unchanged. Recently completed upgrade at the NSCL – Coupled Cyclotron Facility (CCF) and commissioning of new A1900 fragment separator allow measurements of the production cross-sections of these nuclei produced in a proton-removal chain. Recent work also suggests that the cross-sections of such proton removal chain are related to the neutron separation energies of these nuclei. As few experimentally measured values of neutron separation energies have been determined near the neutron drip-line (the drip line is the location of the maximum of neutrons for a certain element, beyond which, the isotope becomes unstable). This summer we would like to work with an REU student to analyze the proton removal data we currently have obtained. We also expect that there will be opportunities to participate in experiments with our research group including measuring production cross-sections of nuclei produced in projectile fragmentation experiments.

 

TITLE: Theory of Femtometer Source Measurements (theoretical)

SUPERVISOR: Prof. Scott Pratt

ABSTRACT:

In the fireball created in ultrarelativistic collisions of nuclei, a mesoscopic region is created with such high temperatures that color is effectively deconfined and the QCD structure of the vacuum is melted. Unfortunately, observables are confined to determining the asymptotic momenta of the explosion's debris. Two-particle correlations can be exploited to provide a space-time picture of the reaction. This project would involve studying the distorting influence of third-body interactions with respect to the imaging of the source. The first part of the project would consist of composing a computer code modeling three-body classical interactions. Tune into http://www.bnl.gov/RHIC/ for details about the Relativistic Heavy Ion Collider.

 

TITLE: Position-Sensitive Photon Detectors for Nuclear Structure

Studies (experimental; available for 2 students)

SUPERVISOR: Thomas Glasmacher

ABSTRACT:

We are installing an array of 24 position-sensitive NaI(Tl) detector crystals for in-beam gamma-ray experiments with radioactive ion beams. These experiments will be carried out in the fall in collaboration with Japanese scientists from RIKEN.  We invite a student to participate in the detector preparation and in the experiment in the fall.

     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: Measurement of charge-state distributions with the A1900

(experimental)

SUPERVISOR: Dr. Andreas Stolz and Prof. Brad Sherrill

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 for study from among the hundreds produced in nuclear reactions. These individual isotopes can be identified unambiguously with detector systems installed in the A1900. The isotopes produced can have none, one or more electrons attached to the nucleus. The distribution into these so-called charge states should be measured and compared with existing theoretical models. A better understanding of the charge state distributions will contribute to a more effective production of rare isotopes in the A1900. The project involves computer analysis of existing data. There may also be an opportunity to participate in experiments to measure new data.

 

TITLE: Relativistic Heavy Ion Collisions (experimental)

SUPERVISOR: Prof. Gary Westfall

ABSTRACT:

At the Relativistic Heavy Ion Collider (RHIC), gold nuclei are collided at energies high enough to produce a quark gluon plasma (QGP). The STAR Detector is being used to search for the QGP at RHIC using a variety of observables.  One such observable that may help in the search for the QGP is the balance function. The balance function is sensitive to whether a deconfined system of quarks and gluons exists for an extended time or not. This project consists of analysing existing STAR data for proton+proton, deuteron+gold, and gold+gold collsions in terms of the balance function. The resulting comparisons can give information about the time of hadronization in Au+Au collisions at RHIC.

 

TITLE: LEBIT - Trapping of rare isotopes

(experimental; available for 2 students)

SUPERVISORS: Prof. Georg Bollen, Dr. Stefan Schwarz

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 ( http://groups.nscl.msu.edu/lebit/ ). 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 determination of the mass of trapped ions. This allows us to determine how strongly the nucleons are bound together, a very important and basic information. Penning traps, which employ a strong magnetic field for the ion storage, are ideal for this kind of measurement.

   LEBIT is in an advanced stage of construction and the testing of components has started. We are looking for a highly motivated and experimentally skilled student who wants to get hands-on experience in the development, construction, and testing of a complex experimental apparatus. Themes for individual projects range from the design, building and test of dedicated electronics components, the development work for the computer-based control system, to the investigation of the properties of a test beam ion source and other LEBIT components.

 

TITLE: t/He3 as a probe for neutron enrichment (theoretical)

SUPERVISORS: Prof. Betty Tsang and Prof. Pawel Danielewicz

ABSTRACT:

Theoretically, it is predicted that, under right conditions, nuclear matter undergoes the liquid-to-gas phase-transition and that an excess of neutrons accumulates in the low-density (gaseous) phase. To study the problem, one would like to measure the ratios of the free neutron (n) yields to free proton (p) yields from heavy ion collisions. However, it is rather difficult to detect neutrons experimentally, as neutrons do not interact with matter as easily as charged particles. An alternative to measuring the n/p ratios is to measure triton (consisting of 1 p and 2 n) to 3He (consisting of 2 p and 1 n) particle ratios. Data on these charged particles exist for the more proton-rich 112Sn+112Sn collisions and the more neutron-rich 124Sn+124Sn collisions. In this project, we would like to work with an REU student to study the yield ratios of n/p and t/He3 from a model utilizing transport equations. This model includes the formation of light mass=3 nuclei as well as emission of free nucleons. During the summer, an experiment to measure particle ratios has been scheduled. Thus, the student may have the opportunity to participate in the experiments as well, if he/she so desires.

 

TITLE: Development of the HiRA array (experimental)

SUPERVISORS: Prof. Bill Lynch and Dr. Michael Famiano

ABSTRACT: (one REU student)

This summer, we will be working with 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, portions of which are now complete, 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 finishing and developing procedures to use this device. The student will  develop procedures to calibrate this device and will test these procedures on the  HiRA array itself. In addition, the student will participate in an experiment that  our experimental group will run this summer at the Coupled Cyclotron Facility.

 

TITLE: Measurements of neutron and proton flow (experimental)

SUPERVISORS: Prof. Bill Lynch and Dr. Dr. Michael Famiano

ABSTRACT: (up to two REU students)

This summer, we will perform measurements with the Coupled Cyclotron facility of neutron and proton energy spectra for central collisions of heavy nuclei. During these collisions, nuclear matter is compressed and then later expands and disintegrates. The velocities of the outgoing neutrons and protons will give us information about the differences between the forces neutrons and protons feel in the expanding nuclear system. From these force measurements, one can learn how the pressure in a dense system, like a neutron star, depends on the neutron concentration. Students, working on this project, will learn how to make neutron and charged particle detectors work, how experiments are set up and how the whole enterprise can produce data relevant to an interesting scientific problem.

 

TITLE: Radiation Resistant Magnet Development

SUPERVISOR: Al Zeller

ABSTRACT:

I'd like to request an REU student this summer to work on radiation resistant magnet development. We will be fabricating new coils for testing in a new Dewar, scheduled to arrive in May. The project will involve getting coils prepared and testing them for stability and current carrying limits. The student will also do quench calculations to determine how to protect the coils in case of a quench.

 

 

------------------------

CONDENSED MATTER PHYSICS

------------------------

TITLE: Phase transitions in Computational Complexity (theoretical)

SUPERVISOR: Phil Duxbury

ABSTRACT:

This project will be assgned to Andy Jones.

 

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 have a number of possible projects which could be the focus of REU research.

 

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: Local Atomic Structure of Complex Materials Using Advanced

X-ray Scattering Methods

SUPERVISOR: Prof. Simon Billinge

ABSTRACT:

This project is to apply newly developed x-ray scattering methods for studying the local arrangement of atoms in materials that have interesting properties.  It will involve learning methods of computer-based data analysis and structural modelling and applying them to solve a particular problem where local atomic structure has an impact on interesting materials propeties.  The project is fairly computer-intensive but will involve some sample preparation and collecting data in-house and probably at a synchrotron at Argonne National Laboratory in Chicago.  Computer programming expertise is not a requirement, but an aptitude for using a computer is a plus.

 

 

-------------------

HIGH-ENERGY PHYSICS

-------------------

TITLE: Implication of Neutrino Mass in Supersymmetry Models

SUPERVISOR: C.-P. Yuan

ABSTRACT:

The solar and atmospheric neutrino oscillation data suggest that neutrinos have masses. On the other hand, the Standard Model of particle physics predicted that neutrinos are massless. Hence, it is necessary to extend the Standard Model in order to explain neutrino oscillation data. One of such possibilities is to build a supersymmtric model with non-vanishing neutrino masses. It could happen that some of the supersymmetric partners of the neutrinos are light enough that they can be detected experimentally at high energy colliders. Our goal is to build a computer software that can calculate various scattering processes predicted by this new theory model, and to study the consequence of neutrino mass at collider experiments. This project will involve a Ph.D. student to set up the necessary programming for such a new model, and a REU student to run the computer code to obtain the production rates and distributions of various scattering processes. The REU student will learn how to compose Feynman diagrams to describe a scattering process, and to use the code to calculate the production rate and various distributions of the final state particles. From the output of the calculation, the REU student will learn how to draw an interesting conclusion about the implication of the existence of massive neutrinos to high energy collider experiments.

 

TITLE: Parton Distribution Functions

SUPERVISOR: Profs. Wu-Ki Tung and Dan Stump

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.

 

------------

ASTROPHYSICS

------------

TITLE: Variable Stars in the Halo and Globular Clusters

SUPERVISOR: Prof. Horace Smith

ABSTRACT:

Pulsating variable stars are keys to the extragalactic distance scale, tests of the properties of stars, and probes for understanding the formation of the Galactic halo. This project involves the study of pulsating variable stars in the Galactic halo (observed with the Robotic Optical Transient Search Experiment) and in globular star clusters. The ROTSE data have already been obtained, and the task there is to discover and characterize a large number of variable stars north of declination -30 degrees.  Running simultaneously with that project, we will be obtaining new observations of type II Cepheids in globular clusters at the MSU 60-cm telescope.  The REU student would be involved in obtaining the new CCD observations for that part of the project.

 

---------------

GENERAL PHYSICS

---------------

TITLE: Global Heating (experimental)

SUPERVISOR: Simon Billinge

ABSTRACT:

This project will be assigned to Kyle Griffith.

 

TITLE: Acoustics REU Project

SUPERVISOR: Prof. William Hartmann

ABSTRACT:

The acoustics research group studies the ability of human listeners to localize sounds. We are particularly interested in the way that a room environment distorts the physical cues that enable localization and how human listeners cope with those distortions.

   An REU project for the summer of 2003 will make physical measurements of the way that interaural level differences and interaural timing differences in different frequency bands are modified by various rooms. The measurements will lead to headphone experiments in which synthesized interaural difference cues are presented to listeners singly  and in combination to study their effect on sound localization ability and misdirection. Finally, comparison will be made with the patterns of localization errors made by listeners in the actual room environments.