RSPS 2004 Abstracts

 ASNY/RSPS Joint Session


Stellar Formation and Spatial Distributions in S171

Kevin Flaherty, University of Rochester
Advisors: Prof. Judith Pipher and Robert Gutermuth, University of Rochester

S171 is a young stellar cluster containing many stars in the process of forming and in their early life. Infrared images of S171 were taken with STELIRCam at the Fred Lawrence Whipple Observatory atop Mt. Hopkins near Tuscon, Arizona in December 2001. Studying the images taken in three different wavelength bands reveals information about the formation of young stars and of brown dwarfs. Also, the spatial distribution of stars within S171 was studied to gather information about the formation of brown dwarfs.

A Near and Mid-Infrared Study of Young Stellar Cluster S140N

Michael Dunham, University of Rochester
Advisor: Prof. Judith Pipher, University of Rochester

We present the progress of an on-going near-infrared and mid-infrared study of the young stellar cluster S140N using data from both the STELIRCam instrument on the 48 inch (1.2 m) telescope at Whipple Observatory on Mt. Hopkins, Arizona and the Spitzer Space Telescope InfraRed Array Camera (IRAC) instrument.  By combining the near-infrared JHK data with the longer wavelength Spitzer data we investigate both the emission from the stellar photospheres and the emission from their circumstellar disks/envelopes.  A classification of young stellar object type is pursued.


Characteristic Star Forming Scales in Blue Compact Dwarf Galaxies

Evan Flath, Skidmore College
Advisor: Prof. Mary Crone Odekon, Skidmore College

We present the results of a survey of the spatial distribution of resolved young stars in Blue Compact Dwarf Galaxies (BCDs). We use Hubble Space Telescope/Wide Field Planetary Camera 2 images of three BCDs, and apply a multi-resolution cluster finding algorithm to identify groups based on a maximum distance between stars. We analyze the way the groups evolve as we vary this distance. In particular, we look at various measures of the size of groups in order to determine characteristic star-forming scales.

Near-Infrared Imaging of Young Stellar Objects in rho Ophiuchus

Melissa McClure, University of Rochester
Advisors: Prof. W. Forrest and Benjamin Sargent, University of Rochester

Ground based photometry in the near infrared (at  2.19 and 4.68 microns) taken with NASA's IRTF of young stellar objects in the rho Ophiuchus molecular cloud complex is being  used to understand and augment spectra taken with the Spitzer Space Telescope at higher wavelengths.  These combined data will reveal new information about stellar and planetary formation in our galaxy.  We will present an explanation of the data reduction process, images, and resulting photometry.

Better Homes and Gardens on Mars - Terraforming the Red Planet as Science (Fiction)

Aaron Morris, Union College
Advisor: Prof. Steven Sargent, Union College

Terraforming is the process of turning a planet's natural state into one capable of supporting terrestrial life.  This concept may seem like it is straight from the realm of science fiction, but, in fact, is firmly rooted in science. Scientists have posited various principles and theories by which other planets could be made habitable for terrestrial life.  Of all the planets in our solar system, Mars offers the best and relatively easiest opportunity to terraform.  Taking this lead from science, many works of science fiction present a Mars that is terraformed and supporting terrestrial life.  This paper examines the integration of the scientific principles and theories of terraforming into science fiction in terms of the planet Mars.  Kim Stanley Robinson's science fiction series the "Mars Trilogy'' is used to trace this "fictional" approach to terraforming back to the scientific papers and principles from which it is derived.  Terraforming may appear as science fiction, but is truly in the realm of science, as well.


Protoplanet Disks and Eccentric Orbits

Amanda LaPage, University of Rochester
Advisor: Prof. Alice Quillen and Peggy Varniere, University of Rochester

Using two-dimensional hydrodynamic simulations, we have theorized the structure of protoplanetary disks that contains a protoplanet with an eccentric orbit.  As this project continues, we hope to gain a better understanding of the nature of the evolution of disks into protoplanets


Particle and Accelerator Physics


Multiplicity and Pseudo-Rapidity Distributions of 28Si Induced Emulsion Collisions at 14.5A GeV

Patrick Blochle, Canisius College
Advisors: Prof. Michael J. Voytovich, and Prof. G. Singh, Canisius College

A stack consisting of three dozens of electron sensitive emulsion detectors was exposed to a relativistic beam of 28Si at 14.5A GeV energy from the Brookhaven National Laboratory (BNL), Upton, New York.  By employing an along-the-track scanning technique, more than 1000 nuclear interactions were recorded. In the present investigation, we have analyzed a minimum-bias sample of more than 800 nuclear interactions for the measurements of multiplicity of black (Nb), gray (Ng) and relativistic singly-charged shower (Ns) particles. Very high magnification microscopes were employed to measure the space angles of all emitted black, grey and relativistic shower particles in three-dimensional space. Multiplicity distributions of Nb, Ng, and Ns tracks will be presented.  Pseudo-rapidity distributions of relativistic singly-charged shower particles, on the basis of several target sizes in emulsion detector, will be computed and discussed.

Optimization of Storage Ring Optics

Elisa Pueschel, Binghamton University
Advisor: Prof. David Rubin, Cornell University


A goal of accelerator machine research is to establish operating parameters that correspond to high luminosity, small beam size, and long beam lifetime.  Computer simulations were used to determine promising machine tunes for Cornell's Electron Storage Ring.  Additionally, the mechanics of the beam-beam interaction at the collision point were studied.


A 200 keV Electrostatic Accelerator

Peter Brady, Houghton College
Advisor: Prof. Mark Yuly, Houghton College


The original 200 keV electrostatic electron accelerator at Houghton College used a glass acceleration tube with external copper equipotential rings to provide the required uniform electric field along the length of the tube.  Unfortunately, in this design stray electrons striking the walls of the tube caused charge to accumulate on the inside wall, eventually deflecting the electron beam.  In order to solve this problem, a new design for the acceleration tube is being tested, made up of 51 pairs of alternating aluminum and plastic rings, with inside diameters 3.8 cm  and 5.1 cm respectively.  The differing inner radii of the rings ensure that the electrons will only strike the aluminum rings, and can therefore be removed as part of the coronal current flowing down the exterior column.


Optical Systems


A Time Resolved Double Pump-Probe Experimental Technique to Characterize Excited-State Parameters of Organic Dyes


Andrew Jensen, U.S. Military Academy, West Point
Advisor: Captain Louis Florence, U.S. Military Academy, West Point


Double pump-probe spectroscopy can be used to characterize the nonlinear optical response of reverse saturable absorbers whose properties make them good candidates for use in eye and optical sensor protection applications.  To that end we have constructed a double pump-probe spectroscopy experiment based on a design validated by Swatton et al. [1].  In a double pump-probe experiment, two pulses sequentially excite the sample so that photo-physical properties of various quantum states involved in the optical absorption process can be measured. The use of a mode-locked, pulsed laser allows resolution in the picosecond regime.  The double pump-probe apparatus was used to characterize the excited-state parameters of 2,3-naphthalocyanine bis(trihexylsiloxide) (SiNC).  Specifically, we measured the differential transmittivity of SiNC for the ultimate characterization of lifetimes and cross sections for excited state transitions.  With some refinement, the experimental apparatus created in this experiment may be used to test the nonlinear optical properties of a variety of materials. (Stewart Swatton, Kevin Welford, and Richard Hollins. Defence Evaluation and Research Agency, Malver, Worchestershire WR14, 3PS, United Kingdom 1997). 


Three-Dimensional Optical Confinement of Microscopic Objects a.k.a. Optical Tweezers
 
Patrick Crawford, Colgate University
Advisor:  Prof. Enrique Galvez, Colgate University

We have created a laser tweezer using an inverted microscope which is able trap and manipulate objects.  So far we have trapped 1-5 micron sized latex spheres immersed in water and controlled them in three dimensions.  We are currently advancing our project to incorporate two acoustical optical modulators.  This will give us computer control of our optical system, multiple traps, as well as the ability to rotate elongated objects.


An Inexpensive Method of Schlieren Imaging

Matthew M. Waters, Rochester Institute of Technology
Advisor: Prof. Robert Teese, Rochester Institute of Technology
          
Schlieren imaging is a form of photography that captures disturbances in the paths of light.  This technique of imaging can be used to capture changes within a medium that are not visible to the human eye, such as convection currents in air.  Schlieren methods have been around for more than one hundred years, and there are many useful applications.  The drawback of most schlieren photographic methods is setting up the complicated lens and camera system properly and the expense of the high quality optical equipment (lenses and/or mirrors).  This paper will outline the principles of schlieren optics, and then describe our technique that takes advantage of the inactive areas between the pixels of a CCD chip to create a sensitive schlieren optical system that does not use expensive optics and is easy to set up.

Poster Session



Feasibility Study for Measuring Three-Nucleon Force Effects in Neutron-Deuteron Breakup

Peter Brady, Christopher Wells, Blake Winter, Houghton College
Advisor: Prof. Mark Yuly, Houghton College
      
The feasibility of a measurement of the differential cross-section for the neutron-deuteron breakup reaction d(n,np)n is being studied as a probe of the three-nucleon component of the strong force (3NF).  Theoretical calculations predict that the breakup reaction is most sensitive to 3NF effects at forward neutron and proton scattering angles far from quasi-free kinematics.  An initial study was made at the Los Alamos Neutron Science Center (LANSCE) in which incident neutrons were scattered by a liquid deuterium target.  Liquid scintillator neutron detectors and CsI proton detectors were placed at angles ranging from 8º to 24º on either side of the beam line.  A neutron detector was also placed at 109.2º for normalization to elastic scattering. Preliminary results indicate that this setup is inadequate to make a useful measurement of the very small break-up cross section, because of the combination of high background accidental coincidence rate, detector-to-detector scattering, and small detector solid angle.   In order to achieve useful results, possible changes, such as the use of a magnetic spectrometer for proton detection and a large solid angle neutron scintillator detector, are being considered.



Complex Systems/Environmental Physics


Iceland is a Heat Island

Vikas Patel, State University of New York at Buffalo
Advisor: Prof. David H. Douglass, University of Rochester

We have calculated temperature trend line over the time period of 1979 to 1996 using various temperature data sources including weather stations on Iceland. We studied one of the “hot” spots, so-called N1 over Germany/Netherlands, in detail. We found that there is another hot spot concentrated over Iceland, which we were not able to see before because it was overwhelmed by N1. Iceland is formed of lava from volcanoes on the island. Some part of the plateau is under the sea. The center of the spot is on the northeastern edge of Iceland and over the sea. We studied the pressure trend line maps and we were not able to find similar feature around Iceland as it is in temperature maps. So, clearly the hot spot corresponds to some geothermal activity under the sea that is heating the atmosphere around the island and not due to CO2 or sulfate or other factors. Thus, we obtained a thermal “finger print” of Iceland, which means that Iceland is a heat island.

Dynamics of a Bouncing Elastic Dumbbell

Grayson Ross, Rochester Institute of Technology
Advisor: Prof. Scott Franklin, Rochester Institute of Technology

Observing a completely elastic dumbbell bouncing on a rigid surface reveals some surprising dynamics.  A simple computer program utilizing the Newton-Raphson root finding method models this system.  Energy is strictly conserved.  Knowing the dumbbell's velocity, angular velocity, and angle to the horizontal right before a collision, we can apply conservation of energy and a relation between linear and angular impulse from the floor to find the new linear and angular velocity after the collision.  The Newton-Raphson method then finds the time of the next collision and the process repeats.  Although the motion of the dumbbell at first appears chaotic (or, at best, quasi-periodic), for certain initial conditions the motion becomes periodic.


Dynamics of an Elastic Bouncing Dumbbell on a Periodically Oscillating Plate

Bill Orr, Rochester Institute of Technology
Advisor: Prof. Scott Franklin, Rochester Institute of Technology

A bouncing ball on a periodically moving plate exhibits a variety of dynamical behaviors, from periodic to chaotic motion.  Our work builds upon this by bouncing a rotating rod on a bouncing plate.  This system is simulated by the use of a simple computer program using the Newton-Raphson root finding technique.  Energy is conserved at collision between the rod and the plate, so it is possible to find the new rotational and horizontal velocities at intersection.  I will describe different behaviors observed as the plate vibration frequency is increased and also the dependence on aspect ratio (length/width of the dumbbell).


Jamming in a 2D Prolate Granular Material System

Jesus Benhumea, Rochester Institute of Technology
Advisor: Prof. Scott Franklin, Rochester Institute of Technology

A two dimensional pile of long rods is one of the simplest systems in which jamming can occur.  In our experiment, a test object is pushed through a 2D array of 2.5"x0.125"x0.125" brass rods.  We can vary the aspect ratio (length:width) of the rods.  We are investigating the packing fraction (fraction of total area covered by particles) at which the system experiences a transition from only a few rods moving to a large cluster moving as a whole. We are attempting to measure the force needed to move the pile and its dependence on initial packing fraction.  Through video analysis we quantify the disturbance induced by the moving test object, measuring its spatial extent.  We also look at how particles that are disturbed become more aligned.  Preliminary results indicate the transition to a more jammed state occurs, for particles with an aspect ratio of 20, at about 30%.

Applied Physics



Test of Ladder-Track Design for Inductrack Magnetic Levitation

David Starling, Becky Lindstrom, State University of New York at Fredonia
Advisors: Prof. Michael Grady and Prof. Peter Mattocks, State University of New York at Fredonia

Inductrack is a proposal for vehicle magnetic levitation using permanent magnets in a Halbach array and a track of fixed coils.  Our early design created to test this theory consisted of vertical coils using insulated litz wire with many turns; however, the low inductance/resistance ratio of the coil made this design impractical.  Our latest design uses a moving cart mounted with contiguous horizontal coils in the form of a bus-bar ladder and a stationary double-Halbach array mounted to force sensors.  A numerical inductance calculation of the newer design predicts a crossover speed (i.e. the lift force equals the drag force) of 9.7m/s.  The experiment yielded significant lift forces at speeds of 6m/s (the cart's current maximum speed).  The unexpectedly large drag forces at this speed, which are likely attributed to eddy currents, appear to be too large to be practical.  Future plans consist of tests to verify the amount of drag created by eddy currents and devise measures to reduce them, to verify the crossover speed calculated using theory, and to create a working model.


Optical Observation of Plasma Current Sheets

Andrew Collette, University of Rochester
Advisor: Prof. Walter Gekelman, University of California, Los Angeles

Plasma current sheets are extremely important for many fields of study, including astrophysics, solar behavior, the study of Earth's auroras, and plasma-based spacecraft propulsion systems.  Traditional observation of these structures has been limited to electrical and magnetic sampling (Langmuire probes, etc.)  We present a new probe that uses optic fibers to observe the plasma light directly, over small distances.  A simple current sheet generated in a weakly-ionized plasma provides proof-of-concept and interesting data on current-sheet behavior, which are in agreement with theo


GMR Effects in Magnetic Thin Films

Fionnbarr O'Grady, Binghamton University
Advisor: Prof. J. Q. Wang, Binghamton University

Giant Magnetoresistance, first discovered in 1988, is the phenomenon by which the resistance of a metal changes dramatically when subjected to an external magnetic field.  Since its discovery, it has revolutionized the data storage industry but there are still many prospects for new technologies that can come from GMR.  The effect is seen especially in thin films of ferromagnetic materials with spacer layers of non-magnetic materials between them.  To study GMR effects we create samples of thin films using ion beam sputtering deposition technology.  This technology is capable of creating samples only a few nanometers in width.  Ions are accelerated through a potential difference to collide with a sample.  The ion beam then sputters, or knocks off atoms of the target material, which are then collected on a substrate.  Samples of different thickness can be prepared by varying a number of parameters, such as the accelerating potential or deposition time etc.  Once the samples are created, we pattern them using chemical etching techniques.  Finally the sample has a large magnetic field applied to it using a superconducting electromagnet.  Probes are connected to the sample and a number of parameters are measured as a function of the applied magnetic field, including any change in resistance as well any voltage that develops perpendicular to the current flow (hall voltage).


Shear Viscosity Under Schock-Loading Conditions

Zhuohan Liang, Unversity of Rochester
Advisor: Prof. Steven M. Valone, Los Alamos National Laboratory, Los Alamos, NM

Since the Transition-State Theory (TST) model was first derived in the 1930's, it has been widely applied to chemical reactions under various conditions.  While it is able to provide us a simple and general explanation for a reaction process under thermal conditions, the model does not work well under shock-loading condition.  Valone re-derived reaction rate constants to account for the particle-velocity dependence in shock-activated processes.  The current study extends this result to the calculation of viscosity under shock-loading conditions.  Our model of shock activated viscosity gives values which are different enough from Eyring's TST model to change the flow regime.


Condensed Matter and Biophysics


Incorporating Individual Carbon Nanotubes into a Broadband Antenna to Measure their High Frequency Response

Anthony J. Annunziata, Colgate University
Advisor: Prof. Beth Parks, Colgate Unviersity

Carbon nanotubes are nanometer diameter hollow tubes of carbon that are ideal one-dimensional conductors. They are being developed as elements in molecular electronics. This application requires characterization of nanotubes at very high frequencies (THz).  This project facilitates such study by incorporating individual carbon nanotubes into broadband (bow tie) antennas for characterization using terahertz time domain spectroscopy. Absorption spectra will be compared to an existing model of high frequency electron transport in one dimension (based on Luttinger liquid theory). Antenna and related microstructures were designed and patterned on a sapphire substrate using optical photolithography at the Cornell Nanofabrication Facility. Carbon nanotubes are grown using chemical vapor deposition in conjunction with the McEuen research group at Cornell University.

Temperature-Dependent Phase Behavior of a 2-Component Membrane Mixture

Matthew Schutzer, Colgate University
Advisor: Prof. Jeffrey Buboltz, Colgate University

Biological membranes can perform a variety of different functions, and their variable compositions are a reflection of this fact.  Recently, there has been a lot of interest in the possible roles that may be played by localized biomembrane environments (a.k.a. membrane domains, or “rafts”).  As part of a larger effort to understand membrane domains, our laboratory at Colgate is developing techniques for mapping out the conditions under which alternative membrane environments will form within a mixture of membrane components.  Using Fluorescence Resonance Energy Transfer between differentially partitioning membrane probe molecules, we can identify the membrane compositions that spontaneously separate into distinct coexisting environments.  As a demonstration of the potential of this technique, we will present results from a temperature-dependent study of a 2-component membrane mixture.

Vortex-Breather Interactions in Superconducting Circuits

Christopher Ritacco, Colgate University
Advisor: Prof. Kenneth Segall, Colgate University

We look at nonlinear dynamics in Josephson junction ladders.  Specifically, we will observe interactions between breather modes and moving vortices in a ladder.  The talk will focus on how Josephson junctions work, what results we expected to get, and what results we obtained.


Quantum Mechanical Systems



Exponentially-Decaying Perturbation in Bound Quantum States

George Bruhn, University of Rochester
Advisor: Prof. Joseph Eberly, University of Rochester

Time-dependent perturbation theory is used to analyze the behavior of bound states in the presence of an electric field that is decaying exponentially with time.  Transition probabilities are derived for an electron in an infinite square well, and these results are applied to the Hydrogen atom, which is a more complicated system whose unperturbed eigenfunctions are well-known.  From this, transition rules and a scaling relation in the atom are found.

Quantum Mechanics Violates Bell Inequalities

Catherine Prueitt, University of Rochester
Advisor: Prof. Joseph Eberly, University of Rochester

This talk will explain the Bell Inequality Theorem and apply it to quantum mechanics through an analysis of Clauser’s experimental version of the Einstein-Podolsky-Rosen paradox.  It will be shown that quantum mechanics predicts, and experiments confirm, a direct violation of Bell’s Theorem in reference to the polarization of correlated photons.  This violation seems to undermine locality.


Liberated Electrons from H-/H Sources in Electric and Magnetic Fields: A Theoretical Study of Order and Chaos in Quantum Systems

Andrew McUmber, Binghamton University
Advisors: Prof. J. B. Delos and Prof. K. Mitchell, College of William and Mary

The behavior of a free electron in external, uniform electric and magnetic fields is described using classical mechanics.  The behavior also depends on the local emission source of the electron.  For two such sources, hydride (H-) and hydrogen (H), liberated electrons will behave differently, producing orderly and chaotic results, respectively.  Electrons from H-emitters in the field arrangement produce an orderly 'corkscrew' motion, whereas electrons from H emitters produce additional chaotic effects due to the coulomb field.  As of yet, only the H- case has been studied extensively.  As a prelude to the dual-field arrangement, the path characteristics and matter wave interference pattern of the particles in a uniform electric field were examined.  The equations of motion yield predictions for the destinations of the freed particles.  Computer-assisted graphs are employed to visualize the expected outcomes.