Project examples

Below are examples of REU projects from the various fields represented in the department. The following are only examples; there will be many others. Given the wide range of interests of the faculty, we will be able to develop other projects to accommodate the interests of the REU applicants.

Astrophysics Condensed Matter Physics High Energy Physics Nuclear Physics

Astrophysics
Project Coordinator: S. Kawaler

Stellar Pulsation Projects

Kawaler's research specialty is the study of the evolution of stars, using computational models of stellar evolution in concert with observations of stellar oscillations. Kawaler directs the NSF-sponsored Whole Earth Telescope project. This collaboration works towards obtaining uninterrupted, 24 hour/day, photometric time-series observations of variable stars. With the headquarters for the Whole Earth Telescope (WET) at Iowa State, there are ample opportunities for students in this and related areas. One project is to use previously obtained WET data on a target, to look for subtle changes in the pulsational phase of a star that may result either from the secular evolution of the star or from the orbital effects of possible sub-stellar companions. Using the WET data along with other archival data, the student will develop skills in time-series analysis as well as in orbital mechanics. Another project of appropriate scale involves working with stellar models to try and reproduce the observed pulsation frequencies in stars. This project will expose the student to modern stellar evolution and structure codes, provide experience running the codes and understanding what they do as well as the outputs produced. In addition, the student will need to calculate oscillation frequencies of the models, in the process learning about eigenmode calculations for spherical systems somewhat larger than those encountered in quantum mechanics.

Studies of Long-Period Variable Stars

Systematic study of the properties of Mira variables has become possible with the large model grids produced at ISU by George Bowen. Several suitable projects involve analysis of data archives, maintained by NASA and the AAVSO, that make use of insights gained from detailed numerical modeling studies by Bowen and Willson. For example, puzzling phenomena such as the semi-regular behavior of pulsating red giants and the possibility of "dust weather" playing a role in some cases, can form the core of exciting projects. Projects may also explore ways of accessing and analyzing the data using new tools, such as special web browser capabilities under development here.

Design studies for an imaging atmospheric Cherenkov telescope

We are currently preparing for the construction of an array of seven 10 m telescopes, to be located near the Whipple observatory, Tucson, Arizona. The Iowa State group has the responsibility to build the focal plane detectors, including non-imaging optics to concentrate light onto the photo detectors. These light concentrators are currently designed by our group using ray-tracing simulations. Measurements in the laboratory and at the Whipple observatory to test the optical properties of these lightcones would be within the scope of an undergraduate project. The successful student will gain hands-on experience with electronics, optical devices and instruments used to develop particle physics detectors.

Condensed Matter Physics
Coordinator: P. Canfield

Design, growth and characterization of novel magnetic compounds

The design, growth and characterization of new materials is one of the vital areas of CMP research. Many of the current research fields in CMP have been created by the discover / design of new materials. New magnetic materials are important for academic research and industrial applications. Our research group designs and discovers new materials with novel magnetic and electronic properties, mostly in single crystal form. Thermodynamic and transport measurements are performed to identify and understand the nature of the ground state and phase transitions of the new materials. During the course of a summer internship, students can expect to learn crystal growth techniques and gain experience in the measurement of magnetic and electronic properties. Over the past seven year this group has published hundreds of papers on the complex behavior associated with the interaction between local moment magnetism and conduction electrons. A REU student could work on systems such a magnetic superconductors (see Physics Today, Oct. 1998, pg. 40), study the effect that a quasicrystalline lattice has on magnetic ordering, tune the amount of disorder in a magnetic system and measure the effects on ordering temperatures, grow and measure novel heavy Fermion systems, or simply explore new combinations of elements for undiscovered or novel compounds. In each case the REU student would be involved in the growth of single crystal samples and the subsequent measurement of their properties.

Study of Magnetic Structure using X-rays

Over the past five years, X-ray diffraction techniques are finding new applications in the area of magnetic structure determination. A set of techniques have been developed by our group for ab-initio solutions of magnetic structure using both resonant and non-resonant scattering. An undergraduate intern in our group will select among several available projects, and learn how to orient, cut and polish samples using X-ray Laue techniques and single crystal diffraction. Work in the lab will be supplemented by reading and group tutorials. The summer experience will culminate in an experiment, at the Advanced Photon Source, where the student will determine the magnetic structure of the sample he/she prepared and studied in the laboratory.

Frontier Problems in Condensed Matter Theory

We have a long tradition of undergraduate involvement in on-going research in the group. Undergraduates working in our group have gained valuable experience in various areas including: atomistic simulations of the structure and dynamics of atomic and molecular clusters, grain boundary and stacking faults, protein structures, solution of Maxwell's equations in complex media using various methods (e.g transfer matrix, finite-difference-time-domain, plane-wave-expansion). There is also an opportunity for experimental work in the area of fabrication and characterization of photonic crystals (periodic structures with varying refractive indices which can control the behavior and propagation of light) by interacting with our collaborators in electrical engineering (Professor Tuttle) and Materials Science and Engineering (Professor Constant).

Condensed Matter Physics at the Extremes

In the study of new materials, compounds and (electronic) structures, it is important to search for possible quantum effects that only can be observed at extremely low temperatures, close to absolute zero. For this purpose, students can study these systems at Iowa State University using a dilution cryostat, a superconducting high-field magnet and a pressure cell to look how these effects change as the material's environment is tuned through magnetic field and high pressure. The student will acquire knowledge in modern cryotechnology, modern data acquisition systems and obtain insight into an area of physics that was awarded several Nobel prizes in the recent years, amongst them superfluidity of ³He, the quantum Hall effect and the fractional quantum Hall Effect.

Fabrication and studies of organic light-emitting devices (OLEDs)

Following dramatic improvements in their operating lifetimes, OLEDs are beginning to emerge in commercial products. Their great advantages are in the ease of fabrication, flexibility, versatility of design, to the point of fabricating very large matrix arrays or low-cost very large area displays, and they appear poised to gain a dominant position in the future display industry. At present, however, their quantum efficiency (photons out per injected electron), remains stubbornly low at 3%. Improving the efficiency is contingent on understanding the basic physical processes occurring in the devices and designing them to modify these processes. The summer trainee will be involved in fabricating the devices and learning about these basic physical processes which govern their behavior.

Superconductivity

A student will work as an apprentice with a low temperature physics group using a Helium-3 Refrigerator to study the properties of superconductors. There is an initial indication of superconductivity in a class of materials called quasicrystals, and the experiment is to study the thermodynamic and transport properties of these very unusual superconductors. The student will work directly with the major professor on this project and will learn construct apparatus for the measurements, wire circuits, help take data, and analyze the results. The initial goal of the work is to determine whether the free energy difference between the superconducting and normal state follows the Bardeen Cooper Schrieffer theory for other classical superconductors.

High Energy Physics
Project Coordinator: J. Hauptman

Fast Photomultipliers

The collidering beams at the LHC will produce an expanding shell of relativistic particles every 25 ns. Therefore, the detectors must be capable of measuring and reseting itself to zero during this time interval. We will be developing and testing fast photomultiplier bases to solve this problem for the forward calorimeters of the CMS detector. This problem will involve work in small groups of one or two physicists.

Absolute Calibration of Photodetectors

The ISU group has formed a collaboration between the National Institute of Standards and Technology (NIST) and Fermilab to design and build a new instrument capable of measuring the absolute quantum efficiency of a photomultiplier, or any other photodetector. This is being done with the support of Fermilab and the CMS collaboration. This small collaboration will involve work with 4-5 physicists and engineers at ISU, NIST and Fermilab.

BaBar Experiment

Within the BaBar group there are many suitable undergraduate projects available in data analysis and software development (or some combination thereof). The student will work with one or more members of the group to design an analysis and then to develop and write the necessary software within the BaBar framework. This process will require an understanding, and probably an extrapolation, of the current particle identification algorithms, thus adding to the foundation on which future analyses will be built. One possible analysis topic would be a determination of the CKM parameter |V_cb| from $B^0 \rightarrow D^{-}\ell^{+}\nu$ events. It is expected that this analysis will ultimately lead to a publication.

BaBar Background studies

The PEPII accelerator is the source of much of the background seen in the BaBar experiment. The primary contributors to this background are beam gas collisions and synchrotron radiation but they are not well modeled by the current Monte Carlo simulation. A proper understanding of these backgrounds will point the way toward reducing them and will also provide valuable input to many of the physics analyses. Efforts are underway to improve the background simulation and a student could contribute by writing/extending the code which describes the various elements of the accelerator beamline. Help is also needed in making detailed comparisons between the simulated backgrounds and those seen in the real data.

Nuclear Physics
Project Coordinator: M. Rosati

Project examples

Astrophysics Project Coordinator: S. Kawaler