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2007 SPS Outstanding Student Awards for Undergraduate Research
Recipients: 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006 | 2005 | 2004 | 2003 | About the Award


2007 ICPSThese three SPS Outstanding Students represented the United States and presented their research at the 2007 International Conference of Physics Students (ICPS) in London, England, August 10-16, 2007. Expenses for transportation, room, board, and meeting registration were paid by SPS. They also receive a $500 honorarium and a $500 award for their SPS Chapter. In addition, they will be invited to give their research presentation at a SPS Research Session at a national meeting in 2007-08.


Austin Thomas Basye - Abilene Christian University

Austin Thomas BasyeICPS Report & Photos

"Muon Spectrometer Upgrades at PHENIX"

Research Abstract
PHENIX is the largest experiment located on the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. Among its many physics goals, PHENIX seeks to understand the spin structure of the proton. It's muon spectrometer arms detect high energy muons which can be tracked back to w-boson decays, which shed light on this spin structure. This abstract will concentrate on two upgrades to the muon spectrometer arms: 1) a simple and completed electronics upgrade; and 2) an ambitious detector system integration which is currently being designed.

The first upgrade was a reconfiguration of various power distribution and data transfer systems for the Muon Tracker. Prior to this upgrade, access to several electronics crates was near impossible during the several-month long data runs. The digital-to-fiber-optic crates were relocated to the electronic rack platforms for easy access. Secondly, all the low voltage distribution crates were reconfigured. We introduced junction boxes which allowed the large diameter cables from the Front End Electronics to transition to smaller diameter cables before they entered the distribution crate. This allowed individual cables to be modified within the crate without disturbing their neighbors. Also, the distribution panel allowed for quick and easy voltage tests due to the junction blocks we elected to used. These upgrades have significantly improved the quality and quantity of the data recoded from the muon arms.

Secondly, the NSF funded a $2 million upgrade to the level 1 triggers of the Muon Tracker by providing funds to build an Resistive Plate Chamber (RPC) sub-system. Designing and integrating these detector modules has proven to be a daunting, but not impossible, task. Our primary design goals are currently: simplicity, ease of integration, spacial efficiency, spatial resolution in both ÿ and ÿ, and mechanical redundancy. Data taken for proton spin physics need fast triggering so that they can reconstruct probable w-boson decays. The RPCs will provide the Muon Tracker with the ability to trigger on high-transverse-momentum (pT) muons, eliminating a large low-pT muon background. This background will only get worse as RHIC upgrades to 500GeV beams at higher luminosities. As simplicity and timing are a few of the many strengths of this type of RPC technology, we wanted to preserve them in our designs. However, we needed to push its resolution and efficiency boundaries to its limit. Also, we wished to make them symmetric, as this will simplify the reconstruction effort while allowing us to produce generic backup modules in the event that one fails and needs to be replaced. Unfortunately, many of these goals tend to be mutually exclusive and thus require innovative mechanical optimization. The design I am currently helping to develop meets these goals.

The PHENIX muon spectrometers have produced valuable results in the past and we anticipate that with these upgrades they will be able to take full advantage of RHIC's new capabilities. As a result, answers to the mysteries of proton spin structure and of quark-gluon phases appear to be closer than ever.

 
Gregory Carson - University of Southern Mississippi
Gregory CarsonICPS Report & Photos

"Characterization of a Rubidium Magneto-Optical Trap"


Research Abstract
Recently at the University of Southern Mississippi, rubidium atoms were cooled and trapped in a standard magneto-optical trap (MOT) to a temperature 1/10,000 of a degree above absolute zero. This presentation includes a description of the basic operating principles of a magneto-optical trap, along with an overview of our apparatus, and the laser control mechanism. A systematic characterization of the rubidium MOT in terms of the total number of trapped atoms versus several laser intensities, laser detunings, and magnetic field gradients is currently under way, with the goal of finding the best experimental conditions in which the number of trapped atoms is the highest. Measurements of the total number of trapped atoms versus the rubidium vapor pressure will also be performed. The total amount of fluorescence emitted by the cold atoms is measured with a calibrated photodetector subtending a known solid angle, while a high-speed video camera connected to a computer via an image acquisition board is used to monitor the size and the shape of the atomic cloud. A two-level atom model will then be used to relate the fluorescence collected by the photodetector with the total number of atoms in the trap. The high-speed video camera will be used to study the loading process of the trap, as well as the cold cloud expansion when the magnetic field is turned off. The first experimental results will be presented at the meeting.
 
Yun Kyoung Ryu - Ohio Wesleyan University

Austin Thomas BasyeICPS Report & Photos

"Lifetime Measurements and Deformation in 79Sr"

Research Abstract
High-spin states in 79Sr were produced following the 54Fe(28Si, 2pn) fusion-evaporation reaction using a beam kinetic energy of 90 MeV at the Florida State University (FSU) Tandem-Linac particle accelerator facility, and the resulting de-exciting γ rays were detected with the FSU array of 10 Compton-suppressed high-purity Ge detectors comprised of three Clover detectors and seven single-crystal detectors.  The 54Fe target was thick enough so that all of the synthesized nuclei could stop completely in the target, resulting in Doppler-shifted γ-ray line shapes that could be analyzed using the Doppler-shift attenuation method. The experimental line shapes were acquired at detection angles of 35° and 145°, and the resulting Doppler-shifted peaks were analyzed to extract the lifetime of their parent states.  In all, 23 lifetimes were measured in three separate band structures using this method, and then used to infer transition quadrupole moments (Qt) and quadrupole deformations (β2) using the rotational model. The resulting Qt values indicated a high degree of collectivity and deformation in all three observed sequences of excited states (bands) with only a modest decline in collectivity with increasing angular momentum.  The results show good qualitative agreement with the predictions of both cranked Woods-Saxon (CWS) and projected shell model (PSM) calculations.  In addition, the pattern of excited energy states and their de-exciting gamma-ray transitions (level scheme) was re-examined and compared to the most recent study of 79Sr using γ - γ coincidence measurements, intensity measurements, and directional correlation of oriented nuclei (DCO) ratios in addition to the lifetime measurements.  Overall, the level scheme from this previous work was verified, with the exception of the re-arrangement of one transition which links two separate decay structures together.  The band based on the intrinsic d5/2 single-particle orbital from the shell model, the existence of which was verified in this study, was found to have the largest average deformation (β2,ave = 0.41) among the three observed bands, in agreement with the CWS and PSM theoretical predictions.  The measurement of lifetimes in this band also represents only the second such measurement in the mass 80 region in a band with an intrinsic structure based solely on the occupation of the d5/2 orbital by a single nucleon (a neutron in this case).

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